Assessing Knowledge, Competence, and Performance Following Web-Based Education on Early Breast Cancer Management: Health Care Professional Questionnaire Study and Anonymized Patient Records Analysis

BACKGROUND

Web-based learning activities are key components of continuing medical education (CME) for health care professionals (HCPs). However, the published outcomes of web-based educational interventions for early breast cancer (EBC) are limited.

OBJECTIVE

This study aims to objectively assess knowledge, competence, and performance among HCPs following participation in 2 EBC-focused CME activities and to identify the remaining educational gaps.

METHODS

We developed 2 CME-accredited web-based educational activities addressing high-risk EBC, including integration of shared decision-making to optimize patient care (touchMDT) and stratification for early identification of high-risk patients and novel treatment strategies (touchPANEL DISCUSSION). Knowledge, competence, and performance were assessed before and after the activities against an expanded outcomes framework (levels 1-5) using self-reported questionnaires and an analysis of anonymized data extracted from patient records.

RESULTS

Six months after the launch of the activity, 7047 and 8989 HCP participants engaged with touchMDT and touchPANEL DISCUSSION, respectively. The overall satisfaction was 82% (a total score of 20.6 out of 25) for the touchMDT and 88% (a total score of 21.9 out of 25) for the touchPANEL DISCUSSION. For the evaluation of knowledge and competence (50 respondents before the activity and 50 learners after the activity), there was a significant increase in the mean number of correctly answered questions from pre- to postactivity (touchMDT: median 4.0, IQR 3.0-5.0 to median 5.5, IQR 4.0-7.0; mean 4.00, SD 1.39 to mean 5.30, SD 1.56 and touchPANEL DISCUSSION: median 4.0, IQR 4.0-5.0 to median 6.0, IQR 5.0-7.0; mean 4.32, SD 1.30 to mean 5.88, SD 1.49; both P<.001). A significant improvement in self-reported performance (50 respondents before the activity and 50 learners after the activity) was observed in a combined analysis of both activities (median 3.0, IQR 2.0-3.0 to median 4.0, IQR 3.0-5.0; mean 2.82, SD 1.08 to mean 4.16, SD 1.45; P<.001). Patient record analysis (50 respondents before the activity and 50 learners after the activity) showed that the HCPs used a range of measures to determine EBC recurrence risk and revealed no significant differences in adjuvant therapies used before and after the activity (P=.97 and P>.99 for Ki-67 <20% and Ki-67 ≥20% tumors, respectively). The remaining educational gaps included strategies for implementing shared decision-making in clinical practice and the use of genetic and biomarker testing to guide treatment selection.

CONCLUSIONS

Brief, web-based CME activities on EBC were associated with an improvement in HCP knowledge, competence, and self-reported performance and can help identify unmet needs to inform the design of future CME activities.

Explained variation and degrees of necessity and of sufficiency for competing risks survival data

In this contribution, the Schemper-Henderson measure of explained variation for survival outcomes is extended to accommodate competing events (CEs) in addition to events of interest. The extension is achieved by moving from the unconditional and conditional survival functions of the original measure to unconditional and conditional cumulative incidence functions, the latter obtained, for example, from Fine and Gray models. In the absence of CEs, the original measure is obtained as a special case. We define explained variation on the population level and provide two different types of estimates. Recently, the authors have achieved a multiplicative decomposition of explained variation into degrees of necessity and degrees of sufficiency. These measures are also extended to the case of competing risks survival data. A SAS macro and an R function are provided to facilitate application. Interesting empirical properties of the measures are explored on the population level and by an extensive simulation study. Advantages of the approach are exemplified by an Austrian study of breast cancer with a high proportion of CEs.

Is the CTS5 a helpful decision-making tool in the extended adjuvant therapy setting?

PURPOSE

The Clinical Treatment Score post-5 years (CTS5) is an easy-to-use tool estimating the late distant recurrence (LDR) risk in patients with hormone receptor-positive breast cancer after 5 years of endocrine therapy (ET). Apart from evaluating the prognostic value and calibration accuracy of CTS5, the aim of this study is to clarify if this score is able to identify patients at higher risk for LDR who will benefit from extended ET.

METHODS

Prognostic power, calibration, and predictive value of the CTS5 was tested in patients of the prospective ABCSG-06 and -0a6 trials (n = 1254 and 860 patients, respectively). Time to LDR was analyzed with Cox regression models.

RESULTS

Higher rates of LDR in the years five to ten were observed in high- and intermediate-risk patients compared to low-risk patients (HR 4.02, 95%CI 2.26-7.15, p < 0.001 and HR 1.93, 95%CI 1.05-3.56, p = 0.035). An increasing continuous CTS5 was associated with increasing LDR risk (HR 2.23, 95% CI 1.74-2.85, p < 0.001). Miscalibration of CTS5 in high-risk patients could be observed. Although not reaching significance, high-risk patients benefitted the most from prolonged ET with an absolute reduction of the estimated 5-year LDR of - 6.1% (95%CI - 14.4 to 2.3).

CONCLUSION

The CTS5 is a reliable prognostic tool that is well calibrated in the lower and intermediate risk groups with a substantial difference of expected versus observed LDR rates in high-risk patients. While a numerical trend in favoring prolonged ET for patients with a higher CTS5 was found, a significantly predictive value for the score could not be confirmed.

CLINICAL TRIAL REGISTRATION

ABCSG-06 trial (NCT00309491), ABCSG-06A7 1033AU/0001 (NCT00300508).

Patient-reported outcomes in high-risk HR+ /HER2- early breast cancer patients treated with endocrine therapy with or without palbociclib within the randomized PENELOPEB study

BACKGROUND

The PENELOPEB trial investigating efficacy and safety of additional 1-year post-neoadjuvant palbociclib to standard endocrine therapy (ET) high-risk hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) early breast cancer patients failed to improve invasive disease-free survival (iDFS). This analysis compared patient-reported outcomes (PROs) between treatment groups.

PATIENTS AND METHODS

Patients received 13 cycles of palbociclib 125 mg/day (n = 631) or placebo (n = 619) orally for 3 out of 4 weeks + ET. European Organization for Research and Treatment of Cancer Quality-of-Life Questionnaire (EORTC QLQ-C30), its breast cancer (BR23) and fatigue (FA13) modules, mood questionnaire GAD7 and European Quality of Life 5 Dimensions (EQ-5D) instruments were used for the assessment of quality of life (QoL). Repeated-measures mixed-effects models were used to evaluate differences in PRO, changes of PRO over time, and treatment-by-time interactions.

RESULTS

924 of 1250 patients (73.9%) completed baseline and at least one post-baseline questionnaire of all PRO instruments. General health status (GHS)/QoL based on EORTC QLQ-C30 was high in both arms (mean [SD]: palbociclib 70.1 [19.3], placebo 71.4 [18.8]) and was slightly higher in the placebo arm (LeastSquare mean difference: 0.82, p < 0.001). Higher fatigue was reported in the palbociclib arm (mean [SD]: 30.3 [23.8] vs. placebo 28.3 [22.7]; p < 0.001). No statistically significant differences were observed among FA13 physical, cognitive, and emotional fatigue subscales.

CONCLUSION

Patient-reported global QoL and fatigue did not substantially change in both treatment arms. Slight differences in GHS, physical functioning, and fatigue favored the placebo arm statistically without achieving clinically meaningful thresholds.

Impact of Imaging-Guided Localization on Performance of Tailored Axillary Surgery in Patients with Clinically Node-Positive Breast Cancer: Prospective Cohort Study Within TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101)

BACKGROUND

Tailored axillary surgery (TAS) is a novel surgical concept for clinical node-positive breast cancer. It consists of the removal of the sentinel lymph nodes (LNs), as well as palpably suspicious nodes. The TAS technique can be utilized in both the upfront and neoadjuvant chemotherapy (NACT) setting. This study assessed whether/how imaging-guided localization (IGL) influenced TAS.

PATIENTS AND METHODS

This was a prospective observational cohort study preplanned in the randomized phase-III OPBC-03/TAXIS trial. IGL was performed at the surgeon's discretion for targeted removal of LNs during TAS. Immediate back-up axillary lymph node dissection (ALND) followed TAS according to TAXIS randomization.

RESULTS

Five-hundred patients were included from 44 breast centers in six countries, 151 (30.2%) of whom underwent NACT. IGL was performed in 84.4% of all patients, with significant variation by country (77.6-100%, p < 0.001). No difference in the median number of removed (5 vs. 4, p = 0.3) and positive (2 vs. 2, p = 0.6) LNs by use of IGL was noted. The number of LNs removed during TAS with IGL remained stable over time (p = 0.8), but decreased significantly without IGL, from six (IQR 4-6) in 2019 to four (IQR 3-4) in 2022 (p = 0.015). An ALND was performed in 249 patients, removing another 12 (IQR 9-17) LNs, in which a median number of 1 (IQR 0-4) was positive. There was no significant difference in residual nodal disease after TAS with or without IGL (68.0% vs. 57.6%, p = 0.2).

CONCLUSIONS

IGL did not significantly change either the performance of TAS or the volume of residual nodal tumor burden.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03513614.

Radiotherapy to regional nodes in early breast cancer: an individual patient data meta-analysis of 14 324 women in 16 trials

BACKGROUND

Radiotherapy has become much better targeted since the 1980s, improving both safety and efficacy. In breast cancer, radiotherapy to regional lymph nodes aims to reduce risks of recurrence and death. Its effects have been studied in randomised trials, some before the 1980s and some after. We aimed to assess the effects of regional node radiotherapy in these two eras.

METHODS

In this meta-analysis of individual patient data, we sought data from all randomised trials of regional lymph node radiotherapy versus no regional lymph node radiotherapy in women with early breast cancer (including one study that irradiated lymph nodes only if the cancer was right-sided). Trials were identified through the EBCTCG's regular systematic searches of databases including MEDLINE, Embase, the Cochrane Library, and meeting abstracts. Trials were eligible if they began before Jan 1, 2009. The only systematic difference between treatment groups was in regional node radiotherapy (to the internal mammary chain, supraclavicular fossa, or axilla, or any combinations of these). Primary outcomes were recurrence at any site, breast cancer mortality, non-breast-cancer mortality, and all-cause mortality. Data were supplied by trialists and standardised into a format suitable for analysis. A summary of the formatted data was returned to trialists for verification. Log-rank analyses yielded first-event rate ratios (RRs) and confidence intervals.

FINDINGS

We found 17 eligible trials, 16 of which had available data (for 14 324 participants), and one of which (henceforth excluded), had unavailable data (for 165 participants). In the eight newer trials (12 167 patients), which started during 1989-2008, regional node radiotherapy significantly reduced recurrence (rate ratio 0·88, 95% CI 0·81-0·95; p=0·0008). The main effect was on distant recurrence as few regional node recurrences were reported. Radiotherapy significantly reduced breast cancer mortality (RR 0·87, 95% CI 0·80-0·94; p=0·0010), with no significant effect on non-breast-cancer mortality (0·97, 0·84-1·11; p=0·63), leading to significantly reduced all-cause mortality (0·90, 0·84-0·96; p=0·0022). In an illustrative calculation, estimated absolute reductions in 15-year breast cancer mortality were 1·6% for women with no positive axillary nodes, 2·7% for those with one to three positive axillary nodes, and 4·5% for those with four or more positive axillary nodes. In the eight older trials (2157 patients), which started during 1961-78, regional node radiotherapy had little effect on breast cancer mortality (RR 1·04, 95% CI 0·91-1·20; p=0·55), but significantly increased non-breast-cancer mortality (1·42, 1·18-1·71; p=0·00023), with risk mainly after year 20, and all-cause mortality (1·17, 1·04-1·31; p=0·0067).

INTERPRETATION

Regional node radiotherapy significantly reduced breast cancer mortality and all-cause mortality in trials done after the 1980s, but not in older trials. These contrasting findings could reflect radiotherapy improvements since the 1980s.

FUNDING

Cancer Research UK, Medical Research Council.

Impact of BMI in Patients With Early Hormone Receptor-Positive Breast Cancer Receiving Endocrine Therapy With or Without Palbociclib in the PALLAS Trial

PURPOSE

BMI affects breast cancer risk and prognosis. In contrast to cytotoxic chemotherapy, CDK4/6 inhibitors are given at a fixed dose, irrespective of BMI or weight. This preplanned analysis of the global randomized PALLAS trial investigates the impact of BMI on the side-effect profile, treatment adherence, and efficacy of palbociclib.

METHODS

Patients were categorized at baseline according to WHO BMI categories. Neutropenia rates were assessed with univariable and multivariable logistic regression. Time to early discontinuation of palbociclib was analyzed with Fine and Gray competing risk models. Unstratified Cox models were used to investigate the association between BMI category and time to invasive disease-free survival (iDFS). 95% CIs were derived.

RESULTS

Of 5,698 patients included in this analysis, 68 (1.2%) were underweight, 2,082 (36.5%) normal weight, 1,818 (31.9%) overweight, and 1,730 (30.4%) obese at baseline. In the palbociclib arm, higher BMI was associated with a significant decrease in neutropenia (unadjusted odds ratio for 1-unit change, 0.93; 95% CI, 0.91 to 0.94; adjusted for age, race ethnicity, region, chemotherapy use, and Eastern Cooperative Oncology Group at baseline, 0.93; 95% CI, 0.92 to 0.95). This translated into a significant decrease in treatment discontinuation rate with higher BMI (adjusted hazard ratio [HR] for 10-unit change, 0.75; 95% CI, 0.67 to 0.83). There was no significant improvement in iDFS with the addition of palbociclib to ET in any weight category (normal weight HR, 0.84; 95% CI, 0.63 to 1.12; overweight HR, 1.10; 95% CI, 0.82 to 1.49; and obese HR, 0.95; 95% CI, 0.69 to 1.30) in this analysis early in follow-up (31 months).

CONCLUSION

This preplanned analysis of the PALLAS trial demonstrates a significant impact of BMI on side effects, dose reductions, early treatment discontinuation, and relative dose intensity. Additional long-term follow-up will further evaluate whether BMI ultimately affects outcome.

Differential immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel in breast cancer patients

BACKGROUND

Epirubicin/cyclophosphamide (EC) and docetaxel (D) are commonly used in a sequential regimen in the neoadjuvant treatment of early, high-risk or locally advanced breast cancer (BC). Novel approaches to increase the response rate combine this treatment with immunotherapies such as PD-1 inhibition. However, the expected stimulatory effect on lymphocytes may depend on the chemotherapy backbone. Therefore, we separately compared the immunomodulatory effects of EC and D in the setting of a randomized clinical trial.

METHODS

Tumor and blood samples of 154 patients from the ABCSG-34 trial were available (76 patients received four cycles of EC followed by four cycles of D; 78 patients get the reverse treatment sequence). Tumor-infiltrating lymphocytes, circulating lymphocytes and 14 soluble immune mediators were determined at baseline and at drug change. Furthermore, six BC cell lines were treated with E, C or D and co-cultured with immune cells.

RESULTS

Initial treatment with four cycles of EC reduced circulating B and T cells by 94% and 45%, respectively. In contrast, no comparable effects on lymphocytes were observed in patients treated with initial four cycles of D. Most immune mediators decreased under EC whereas D-treatment resulted in elevated levels of CXCL10, urokinase-type plasminogen activator (uPA) and its soluble receptor (suPAR). Accordingly, only the exposure of BC cell lines to D induced similar increases as compared to E. While treatment of BC cells with E was associated with cell shrinkage and apoptosis, D induced cell swelling and accumulation of cells in G2 phase.

CONCLUSION

The deleterious effect of EC on lymphocytes indicates strong immunosuppressive properties of this combination therapy. D, in contrast, has no effect on lymphocytes, but triggers the secretion of stimulatory proteins in vivo and in vitro, indicating a supportive effect on the immune system. Underlying differences in the induced cell death might be causal. These divergent immunomodulatory effects of epirubicin/cyclophosphamide and docetaxel should be considered when planning future combinations with immunotherapies in breast cancer.

Understanding breast cancer complexity to improve patient outcomes: The St Gallen International Consensus Conference for the Primary Therapy of Individuals with Early Breast Cancer 2023

The 18th St Gallen International Breast Cancer Conference held in March 2023, in Vienna, Austria, assessed significant new findings for local and systemic therapies for early breast cancer with a focus on the evaluation of multimodal treatment options. The emergence of more effective, innovative agents in both the preoperative (primary or neoadjuvant) and post-operative (adjuvant) settings has underscored the pivotal role of a multidisciplinary approach in treatment decision making, particularly when selecting systemic therapy for an individual patient. The importance of multidisciplinary discussions regarding the clinical benefits of interventions was explicitly emphasized by the consensus panel as an integral part of developing an optimal treatment plan with the 'right' degree of intensity and duration. The panelists focused on controversies surrounding the management of common ductal/no special type and lobular breast cancer histology, which account for the vast majority of breast tumors. The expert opinion of the panelists was based on interpretations of available data, as well as current practices in their professional environments, personal and socioeconomic factors affecting patients, and cognizant of varying reimbursement and accessibility constraints around the world. The panelists strongly advocated patient participation in well-designed clinical studies whenever feasible. With these considerations in mind, the St Gallen Consensus Conference aims to offer guidance to clinicians regarding appropriate treatments for early-stage breast cancer and assist in balancing the realistic trade-offs between treatment benefit and toxicity, enabling patients and clinicians to make well-informed choices through a shared decision-making process.

Association of Axillary Dissection With Systemic Therapy in Patients With Clinically Node-Positive Breast Cancer

Importance

The role of axillary lymph node dissection (ALND) to determine nodal burden to inform systemic therapy recommendations in patients with clinically node (cN)-positive breast cancer (BC) is currently unknown.

Objective

To address the association of ALND with systemic therapy in cN-positive BC in the upfront surgery setting and after neoadjuvant chemotherapy (NACT).

Design, Setting, and Participants

This was a prospective, observational, cohort study conducted from August 2018 to June 2022. This was a preplanned study within the phase 3 randomized clinical OPBC-03/TAXIS trial. Included were patients with confirmed cN-positive BC from 44 private, public, and academic breast centers in 6 European countries. After NACT, residual nodal disease was mandatory, and a minimum follow-up of 2 months was required.

Exposures

All patients underwent tailored axillary surgery (TAS) followed by ALND or axillary radiotherapy (ART) according to TAXIS randomization. TAS removed suspicious palpable and sentinel nodes, whereas imaging-guidance was optional. Systemic therapy recommendations were at the discretion of the local investigators.

Results

A total of 500 patients (median [IQR] age, 57 [48-69] years; 487 female [97.4%]) were included in the study. In the upfront surgery setting, 296 of 335 patients (88.4%) had hormone receptor (HR)-positive and Erb-B2 receptor tyrosine kinase 2 (ERBB2; formerly HER2 or HER2/neu)-negative disease: 145 (49.0%) underwent ART, and 151 (51.0%) underwent ALND. The median (IQR) number of removed positive lymph nodes without ALND was 3 (1-4) nodes compared with 4 (2-9) nodes with ALND. There was no association of ALND with the proportion of patients undergoing adjuvant chemotherapy (81 of 145 [55.9%] vs 91 of 151 [60.3%]; adjusted odds ratio [aOR], 0.72; 95% CI, 0.19-2.67) and type of systemic therapy. Of 151 patients with NACT, 74 (51.0%) underwent ART, and 77 (49.0%) underwent ALND. The ratio of removed to positive nodes was a median (IQR) of 4 (3-7) nodes to 2 (1-3) nodes and 15 (12-19) nodes to 2 (1-5) nodes in the ART and ALND groups, respectively. There was no observed association of ALND with the proportion of patients undergoing postneoadjuvant systemic therapy (57 of 74 [77.0%] vs 55 of 77 [71.4%]; aOR, 0.86; 95% CI, 0.43-1.70), type of postneoadjuvant chemotherapy (eg, capecitabine: 10 of 74 [13.5%] vs 10 of 77 [13.0%]; trastuzumab emtansine-DM1: 9 of 74 [12.2%] vs 11 of 77 [14.3%]), or endocrine therapy (eg, aromatase inhibitors: 41 of 74 [55.4%] vs 36 of 77 [46.8%]; tamoxifen: 8 of 74 [10.8%] vs 6 of 77 [7.8%]).

Conclusion

Results of this cohort study suggest that patients without ALND were significantly understaged. However, ALND did not inform systemic therapy recommendations.

Explaining risks and benefits of loco-regional treatments to patients

Treatment for early-stage breast cancer is complex, requiring multidisciplinary care with a multitude of treatment options available for each patient. Coupled with the rising importance of shared decision-making, patient-physician conversations are progressively more complicated. These conversations require frank disclosure of risks and benefits of the different treatment modalities in a way that is individualized for each patient and simple to understand. In most patients, breast conserving therapy with radiation should be presented as the gold-standard local treatment given similar long-term and improved quality of life outcomes. De-escalation is currently at the forefront of research in loco-regional treatments, and further investigations are required to best determine the optimal patient populations for reduced sentinel lymph node sampling, omission of sentinel lymph node biopsy altogether and omission of radiation treatment. For future trials, better endpoints need to be established considering patient-centered outcomes as well as recurrence.

Updated Austrian treatment algorithm for metastatic triple-negative breast cancer

Approximately 15% of newly diagnosed breast cancer patients have neither hormone receptors expression nor HER2 overexpression and/or HER2/neu gene amplification. This subtype of breast cancer is known as Triple Negative Breast Cancer (TNBC), and carries a significantly elevated risk of local and distant recurrence. In comparison with other breast cancer subtypes, there is a higher rate of visceral and brain metastases. The majority of metastases of TNBC are diagnosed within three years after initial breast cancer diagnosis. While there have been major advances in hormone-receptor- positive and in human epidermal growth factor receptor 2 (HER2)-positive disease over the past two decades, only limited improvements in outcomes for patients with triple negative breast cancer (TNBC) have been observed. A group of Austrian breast cancer specialists therefore convened an expert meeting to establish a comprehensive clinical risk-benefit profile of available mTNBC therapies and discuss the role sacituzumab govitecan may play in the treatment algorithm of the triple-negative breast cancer patients.

Trends in use of neoadjuvant systemic therapy in patients with clinically node-positive breast cancer in Europe: prospective TAXIS study (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101)

PURPOSE

The aim of this study was to evaluate clinical practice heterogeneity in use of neoadjuvant systemic therapy (NST) for patients with clinically node-positive breast cancer in Europe.

METHODS

The study was preplanned in the international multicenter phase-III OPBC-03/TAXIS trial (ClinicalTrials.gov Identifier: NCT03513614) to include the first 500 randomized patients with confirmed nodal disease at the time of surgery. The TAXIS study's pragmatic design allowed both the neoadjuvant and adjuvant setting according to the preferences of the local investigators who were encouraged to register eligible patients consecutively.

RESULTS

A total of 500 patients were included at 44 breast centers in six European countries from August 2018 to June 2022, 165 (33%) of whom underwent NST. Median age was 57 years (interquartile range [IQR], 48-69). Most patients were postmenopausal (68.4%) with grade 2 and 3 hormonal receptor-positive and human epidermal growth factor receptor 2-negative breast cancer with a median tumor size of 28 mm (IQR 20-40). The use of NST varied significantly across the countries (p < 0.001). Austria (55.2%) and Switzerland (35.8%) had the highest percentage of patients undergoing NST and Hungary (18.2%) the lowest. The administration of NST increased significantly over the years (OR 1.42; p < 0.001) and more than doubled from 20 to 46.7% between 2018 and 2022.

CONCLUSION

Substantial heterogeneity in the use of NST with HR+/HER2-breast cancer exists in Europe. While stringent guidelines are available for its use in triple-negative and HER2+ breast cancer, there is a need for the development of and adherence to well-defined recommendations for HR+/HER2-breast cancer.

LM02 trial Perioperative treatment with panitumumab and FOLFIRI in patients with wild-type RAS, potentially resectable colorectal cancer liver metastases-a phase II study

Background

Twenty percent of colorectal cancer liver metastases (CLMs) are initially resectable with a 5-year survival rate of 25%-40%. Perioperative folinic acid, 5-fluorouracil, oxaliplatin (FOLFOX) increases progression-free survival (PFS). In advanced disease, the addition of targeting therapies results in an overall survival (OS) advantage. The aim of this study was to evaluate panitumumab and FOLFIRI as perioperative therapy in resectable CLM.

Methods

Patients with previously untreated, wild-type Rat sarcoma virus (RAS), and resectable CLM were included. Preoperative four and postoperative eight cycles of panitumumab and folinic acid, 5-fluorouracil, irinotecan (FOLFIRI) were administered. Primary objectives were efficacy and safety. Secondary endpoints included PFS and OS.

Results

We enrolled 36 patients in seven centers in Austria (intention-to-treat analyses, 35 patients). There were 28 men and seven women, and the median age was 66 years. About 91.4% completed preoperative therapy and 82.9% underwent liver resection. The R0 resection rate was 82.7%. Twenty patients started and 12 patients completed postoperative chemotherapy. The objective radiological response rate after preoperative therapy was 65.7%. About 20% and 5.7% of patients had stable disease and progressive disease, respectively. The most common grade 3 adverse events were diarrhea, rash, and leukopenia during preoperative therapy. One patient died because of sepsis, and one had a pulmonary embolism grade 4. After surgery, two patients died because of hepatic failure. Most common grade 3 adverse events during postoperative therapy were skin toxicities/rash and leukopenia/neutropenia, and the two grade 4 adverse events were stroke and intestinal obstruction. Median PFS was 13.2 months. The OS rate at 12 and 24 months were 85.6% and 73.3%, respectively.

Conclusions

Panitumumab and FOLFIRI as perioperative therapy for resectable CLM result in a radiological objective response rate in 65.7% of patients with a manageable grade 3 diarrhea rate of 14.3%. Median PFS was 13.2 months, and the 24-month OS rate was 73.3%. These data are insufficient to widen the indication of panitumumab from the unresectable setting to the setting of resectable CLM.

Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors: existing and emerging differences

The cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors palbociclib, ribociclib, and abemaciclib are standard-of-care therapy for hormone receptor-positive advanced or metastatic breast cancer, based on randomized trials showing improved progression-free survival for all 3 drugs and overall survival for ribociclib and abemaciclib. Results in early breast cancer are discordant, with sustained improvement in invasive disease-free survival demonstrated for abemaciclib but not other CDK4/6 inhibitors to date. We review nonclinical studies exploring mechanistic differences between the drugs, the impact of continuous dosing on treatment effect, and translational research into potential resistance mechanisms and prognostic and predictive markers. We focus particularly on how emerging findings may help us understand similarities and differences between the available CDK4/6 inhibitors. Even at late-stage clinical development, there remains much to learn about how agents in this class exert their varying effects.

Third International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions)

The heterogeneous group of B3 lesions in the breast harbors lesions with different malignant potential and progression risk. As several studies about B3 lesions have been published since the last Consensus in 2018, the 3rd International Consensus Conference discussed the six most relevant B3 lesions (atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), radial scar (RS), papillary lesions (PL) without atypia, and phyllodes tumors (PT)) and made recommendations for diagnostic and therapeutic approaches. Following a presentation of current data of each B3 lesion, the international and interdisciplinary panel of 33 specialists and key opinion leaders voted on the recommendations for further management after core-needle biopsy (CNB) and vacuum-assisted biopsy (VAB). In case of B3 lesion diagnosis on CNB, OE was recommended in ADH and PT, whereas in the other B3 lesions, vacuum-assisted excision was considered an equivalent alternative to OE. In ADH, most panelists (76%) recommended an open excision (OE) after diagnosis on VAB, whereas observation after a complete VAB-removal on imaging was accepted by 34%. In LN, the majority of the panel (90%) preferred observation following complete VAB-removal. Results were similar in RS (82%), PL (100%), and FEA (100%). In benign PT, a slim majority (55%) also recommended an observation after a complete VAB-removal. VAB with subsequent active surveillance can replace an open surgical intervention for most B3 lesions (RS, FEA, PL, PT, and LN). Compared to previous recommendations, there is an increasing trend to a de-escalating strategy in classical LN. Due to the higher risk of upgrade into malignancy, OE remains the preferred approach after the diagnosis of ADH.

Uncertainties and controversies in axillary management of patients with breast cancer

The aims of this Oncoplastic Breast Consortium and European Breast Cancer Research Association of Surgical Trialists initiative were to identify uncertainties and controversies in axillary management of early breast cancer and to recommend appropriate strategies to address them. By use of Delphi methods, 15 questions were prioritized by more than 250 breast surgeons, patient advocates and radiation oncologists from 60 countries. Subsequently, a global virtual consensus panel considered available data, ongoing studies and resource utilization. It agreed that research should no longer be prioritized for standardization of axillary imaging, de-escalation of axillary surgery in node-positive cancer and risk evaluation of modern surgery and radiotherapy. Instead, expert consensus recommendations for clinical practice should be based on current evidence and updated once results from ongoing studies become available. Research on de-escalation of radiotherapy and identification of the most relevant endpoints in axillary management should encompass a meta-analysis to identify knowledge gaps, followed by a Delphi process to prioritize and a consensus conference to refine recommendations for specific trial designs. Finally, treatment of residual nodal disease after surgery was recommended to be assessed in a prospective register.

Managing a Long and Winding Road: Estrogen Receptor-Positive Breast Cancer

We review key topics in the management of estrogen receptor (ER)-positive human epidermal growth factor receptor 2-negative breast cancer. The single biggest challenge in management of this disease is late relapse, and we review new methods for identifying which patients are at risk of late relapse and potential therapeutic approaches in clinical trials. CDK4/6 inhibitors have become a standard treatment option for high-risk patients in both the adjuvant setting and the first-line metastatic setting, and we review data on optimal treatment after progression on CDK4/6 inhibitors. Targeting the estrogen receptor remains the single most effective way of targeting the cancer, and we review the developments in new oral selective ER degraders that are becoming a standard of care in cancers with ESR1 mutations and potential future directions.

St. Gallen/Vienna 2023: Optimization of Treatment for Patients with Primary Breast Cancer - A Brief Summary of the Consensus Discussion

The St. Gallen Consensus Conference on early breast cancer treatment 2023 was again a live event and took place in Vienna, Austria. After 4 years and one virtual event due to the pandemic, more than 2,800 participants from over 100 countries came together in Vienna, and the 2023 St. Gallen/Vienna conference was a great success. Over 3 days, the global faculty reviewed the most important evidence published during the last 2 years and debated over controversial topics, and finally, the consensus votes aimed to define the impact of the new data on everyday routine practice. Focuses of this year's conference were radiotherapy and local management of the axilla, genetics, and their impact on treatment, as well as the role of the immune system and tumor-infiltrating lymphocytes in pathological reports and treatment decision-making. The traditional panel votes were moderated for the first time by Harold Burstein from Boston, and with questions previously voted on and live voting, the panel managed for the most part to clarify the critical questions. This report by editors of BREAST CARE summarizes the results of the 2023 international panel votes with respect to locoregional and systemic treatment as a brief news update but does not intend to replace the official St. Gallen Consensus publication that not just reports but also interprets the panel votes and will follow shortly in a major oncological journal. The next (19th) St. Gallen International Breast Cancer Conference will again take place in Vienna (save the date: March 12-15, 2025).

Abstract P1-07-03: Unmet needs and future applications of breast cancer multigene signatures in routine clinical practice: results from the European PROCURE Project

Background: Several Breast Cancer Multigene Signatures (BCMS) are available to profile early breast cancer (eBC) that according to current evidence, can provide reliable information on the risk of recurrence. However, knowledge regarding their perceived value and use in clinical practice is scarce. The first results regarding the panelists’ opinions on the clinical utility of BCMS were presented at SABCS Symposium 2021 (Poster P4-06-08). Here we discuss present and future recommendations for improving the use of BCMS resulting from the PROCURE Project. Methods: The Delphi survey developed by the 8 members of the Scientific Committee was administered twice to oncologists, pathologists, and surgeons across Europe. The questionnaire included 5 sections: 1) Participants’ profile and experience with BCMS, 2) Current clinical practice in eBC and use of BCMS, 3) Participants’ opinion on the utility of the BCMS in eBC according to patient profiles, 4) Agreement with a set of recommendations on the use of BCMS in clinical practice and 5) Identification of unmet needs and future applications of BCMS. 70% agreement was used to determine consensus on a topic. Results: 133 panelists from 11 European countries completed both rounds of the survey. Experts were mostly medical oncologists (72.2%) with extensive experience (more than 5 years) in the management of BC patients (97.0%) and in the use of BCMS (73.4%). Most of them worked in university hospitals (86.5%). Regarding recommendations for improving BCMS utility, according to panelists’ opinion, these genomic tests should provide prognostic as well as predictive information (82.0%), especially to help physicians when deciding on the most appropriate adjuvant chemotherapy (81.2%). Also, their evidence should be based mostly on prospective randomized clinical trials (85.0%) and they should evaluate the clinical and pathological features of the disease (91.0%). Another aspect agreed by panelists is that patients should have the right to access their BCMS results to take part in treatment decisions (85.7%). Finally, when thinking about future applications of BCMS, consensus was only reached after the second Delphi round, and according to panelists, there is a need for validating BCMS in order to know if they can predict treatment benefits in patients with ER-positive advanced/metastatic BC (78.2%) and in triple-negative eBC patients (72.2%). Likewise, panelists also agreed on the need of developing newly validated tests to evaluate the risk of distant recurrence and predict treatment benefits in the neoadjuvant setting (71.4% and 81.2%, respectively). However, no consensus was reached on the need for BCMS to give an accurate prognosis for patients with ER+ advanced and/or metastatic BC (50.4%), HER2+ advanced BC (21.8%), or triple-negative advanced BC (36.8%). Conclusions: The panelists who participated in the PROCURE Project had an extensive experience in the management of eBC patients as well as using BCMS; however, the high degree of importance that they attributed to both prognostic and predictive information reflects a misconception on the correct interpretation of BCMS results because, even if those test can be used to predict the benefit of adjuvant chemotherapy, they are primarily prognostic tools but not predictive about the effect of a specific cytotoxic intervention. These results in conjunction with the agreements regarding treatment benefit prediction reached in the neoadjuvant, the triple-negative eBC, and the metastatic settings reinforce the idea that more training is needed to highlight that BCMS should be used in the context of risk assessment in intermediate-risk eBC as well as the possibility of running those tests in core biopsies.

Citation Format: Michael Gnant, Anne-Vibeke Lænkholm, Aleix Prat, Judy King, Giuseppe Curigliano, Nadia Harbeck, Frédérique Penault-Llorca, Fatima Cardoso. Unmet needs and future applications of breast cancer multigene signatures in routine clinical practice: results from the European PROCURE Project [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-07-03.

Abstract PD17-05: Development and Validation of a Composite Biomarker Predictive of Palbociclib + Endocrine Treatment Benefit in Early Breast Cancer: PENELOPE-B and PALLAS Trials

Background: The PENELOPE-B (NCT01864746) and PALLAS (NCT02513394) trials are large prospective, randomized, phase III trials that evaluated adjuvant palbociclib (PAL) + endocrine treatment (ET) vs ET in patients with hormone receptor–positive/human epidermal growth factor receptor 2–negative (HER2–) early breast cancer (EBC). Both studies did not meet the primary endpoint of improving invasive disease-free survival (iDFS). We conducted biomarker analyses to identify patients who might benefit from PAL + ET in EBC. Methods: Resected tumor tissue was collected from consenting patients. Gene expression analyses were conducted using the HTG EdgeSeq Oncology Biomarker Panel including 2549 genes. Based on 91 genes from the HTG panel, the intrinsic molecular subtypes were calculated using Absolute Intrinsic Molecular Subtyping (AIMS). Potential predictive treatment biomarkers were established in PENELOPE-B (n=906 with resected tissue) as the development set using an outcome-oriented approach based on iDFS with a selection procedure that maximized the log-rank statistic to estimate a standard Z score–based optimal cutoff. Independent validation was conducted on PALLAS (n=2085; PENELOPE-B-like with resected tissue and HTG data). Hazard ratios and corresponding 95% CIs were calculated using the Cox proportional hazards model, and iDFS distributions between treatment arms were compared using the log-rank test. Interaction between treatment and biomarker status was assessed. Results: Patient baseline characteristics were well balanced, with no differences in iDFS between the intent-to-treat set and the biomarker set for both trials. Approximately 73% of patients (PENELOPE-B [n=663] and PALLAS [n=1516]) had luminal A subtypes whereas only 7.1 % (PENELOPE-B [n=64]) and 8.3 % (PALLAS [n=172]) had a luminal B subtype. AIMS subtypes showed overall similar prognostic patterns for iDFS between PENELOPE-B and PALLAS. The biomarker-defined subgroup found in PENELOPE-B with optimal cutoff demonstrated a preferential benefit from PAL + ET (n=364 [96 events]; hazard ratio [95% CI], 0.63 [0.42, 0.95]; P=0.025). Independent validation of the PALLAS subgroup using the pre-defined optimal cutoff confirmed a significant benefit from PAL + ET (n=916 [70 events]; 0.55 [0.34–0.90]; P=0.015) while not in the rest of the patients (interaction p=0.0025). Significant treatment effects remained (0.55 [0.34–0.89]; P=0.015) after adjusting for the randomization stratification factors of PALLAS. Conclusions: The composite predictive biomarker defined from PENELOPE-B was independently validated in a prospectively defined retrospective analysis of a subset of patients selected from PALLAS. The composite biomarker identified a subset of EBC patients deriving benefit from the addition of PAL to ET. This patient stratification approach can potentially be applied to future adjuvant clinical trials for treatment of hormone receptor–positive/HER2– EBC.

Citation Format: Sibylle Loibl, Carsten Denkert, Yuan Liu, Erik S. Knudsen, Angela DeMichele, Zhe Zhang, Julia Teply-Szymanski, Martin Filipits, Peter A. Fasching, Michael Gnant, Shibing Deng, Marija Balic, Federico Rojo, Mark Watson, Chetan Deshpande, Nicholas Turner, Otto Metzger, Kathy Puyana Theall, Agnieszka Witkiewicz, Olga Valota, W. Fraser Symmans, Erica L. Mayer. Development and Validation of a Composite Biomarker Predictive of Palbociclib + Endocrine Treatment Benefit in Early Breast Cancer: PENELOPE-B and PALLAS Trials [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD17-05.

Abstract OT1-01-02: EMBER-4: A phase 3 adjuvant trial of imlunestrant vs standard endocrine therapy (ET) in patients with ER+, HER2- early breast cancer (EBC) with an increased risk of recurrence who have previously received 2 to 5 years of adjuvant ET

Background: Adjuvant ET has been the standard of care for patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) EBC. A significant proportion of patients with increased risk still experience disease relapse despite available ET and more optimum ET is needed to prevent patients developing incurable metastatic cancer. Distant recurrence risk ranges from 20% to 40% after 5 years of adjuvant ET, depending on clinicopathological (clin-path) features at diagnosis. Consequently, there is a need to further optimize adjuvant treatment, particularly in those patients who are at increased risk of recurrence. Imlunestrant is an orally bioavailable selective estrogen receptor degrader (SERD) with pure antagonistic properties and the potential to overcome ET resistance. In early phase trials, imlunestrant monotherapy showed favorable safety with pharmacokinetic (PK) exposures exceeding fulvestrant and preliminary efficacy in ER+, HER2- advanced breast cancer patients (EMBER, Jhaveri 2022) along with robust biological/pharmacodynamic activity and tolerability in EBC (EMBER-2, Neven). Trial Design: EMBER-4 is a randomized, open-label, global phase 3 study comparing imlunestrant versus physicians’ choice of ET, in patients who are at an increased risk of recurrence based on clin-path features and who have received 2 to 5 years of standard adjuvant ET. Approximately 6,000 patients will be randomized 1:1 to receive imlunestrant (400 mg daily) for 5 years or physicians’ choice of adjuvant ET (tamoxifen or an aromatase inhibitor, AI, dosed per label). Study treatment duration is 5 years. Males and pre-/peri-menopausal women will receive concomitant treatment with a GnRH agonist if receiving imlunestrant or an AI. Stratification factors include time from initial adjuvant ET, use of prior adjuvant cyclin dependent kinase 4/6 inhibitors, nodal status, menopausal status, and geographic region. Eligibility criteria: Eligible patients are adult males and females (pre-, peri- or postmenopausal) with ER+, HER2- EBC who have completed definitive locoregional therapy and have received 2 to 5 years of prior adjuvant ET without disease recurrence, but who are at increased risk of recurrence based on clin-path features at diagnosis. Prior (neo) adjuvant chemotherapy and/or targeted therapy with a CDK4/6- or PARP- inhibitor is permitted. Study endpoints: The primary endpoint is invasive disease-free survival (IDFS), excluding second non-breast primary invasive cancers. Key secondary endpoints include distant relapse-free survival, overall survival, IDFS including second non-breast primary invasive cancers, safety, PK and patient reported outcomes. Recruitment for EMBER-4 begins globally in Q4 2022.

Citation Format: Komal Jhaveri, Joyce O’Shaughnessy, Fabrice Andre, Matthew P. Goetz, Nadia Harbeck, Miguel Martín, Francois-Clement Bidard, Zachary M. Thomas, Suzanne Young, Roohi Ismail-Khan, Lillian M. Smyth, Michael Gnant. EMBER-4: A phase 3 adjuvant trial of imlunestrant vs standard endocrine therapy (ET) in patients with ER+, HER2- early breast cancer (EBC) with an increased risk of recurrence who have previously received 2 to 5 years of adjuvant ET [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr OT1-01-02.

Abstract P2-11-15: Focal ESR1 gene amplification is an independent prognostic marker in postmenopausal patients with endocrine-responsive early breast cancer

Purpose: Estrogen receptor (ER) expression predicts response to endocrine therapy and is a prognostic biomarker. However, no ER-associated biomarker is able to identify patients with particularly favorable outcome among ER+ tumors. We investigated the value of ESR1 amplification in predicting long-term outcome in tamoxifen-treated postmenopausal women with early breast cancer with and without nodal involvement. Patients and Methods: 394 patients with ER+ breast cancer (235 node-negative, 159 patients node- positive), who had received adjuvant tamoxifen for 5 years in the prospective randomized ABCSG-06 trial, and in whom FFPE tumor tissue was available, were included in this analysis. ER alpha immunoreactivity was evaluated using the Allred score, while ESR1 gene amplification was evaluated by FISH analysis. Results: Focal ESR1 amplification was detected in 187 (47%) tumors, and was associated with a favorable outcome. After a median follow-up of 10 years, women with focal ESR1 amplification had a significantly longer distant recurrence-free survival (DRFS; adjusted HR 0.48; 95% CI 0.26-0.91; p=0.02) and breast cancer-specific survival (BCSS; adjusted HR 0.47; CI 0.27-0.80; p=0.01) compared to women without ESR1 amplification. The association between ESR1 amplification and improved DRFS and BCSS was only found in node-positive tumors, but not in nodal-negative tumors. ER alpha immunoreactivity, evaluated by Allred score, correlated significantly with focal ESR1 amplification (p&lt; 0∙0001; Chi-squared test), but without prognostic significance. Conclusion: We suggest focal ESR1 amplification as predictor of improved long-term outcome in postmenopausal women with node-positive ER+ early breast cancer.

Citation Format: Christian F. Singer, Frederik Holst, Stefan Steurer, Eike Burandt, Sigurd Lax, Raimund Jakesz, Margaretha Rudas, Herbert Stöger, Richard Greil, Guido Sauter, Martin Filipits, Ronald Simon, Michael Gnant. Focal ESR1 gene amplification is an independent prognostic marker in postmenopausal patients with endocrine-responsive early breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-11-15.

Abstract P2-02-04: De-escalation of bone-targeted treatment: Does the number of 6-monthly adjuvant zoledronate infusions received affect treatment efficacy for early breast cancer? A sub-study of ABCSG-12

Background: The results of the Early Breast Cancer Trialist Group (EBCTCG) meta-analysis (Lancet 2015) led to the widespread adoption of bisphosphonates as adjuvant therapy for postmenopausal early-stage breast cancer (EBC). Despite evaluating multiple bisphosphonate agents and regimens, there was no signal of varying efficacy with different agents, routes of administration or dose/dose intensity. We evaluated the question of treatment de-escalation using long-term outcome data from the prospective randomized ABCSG-12 trial.

Patients and methods: Between 1999 and 2006, ABCSG-12 accrued 1803 patients with hormone-receptor positive EBC on ovarian function suppression for three years that were randomized to receive 4 mg zoledronic acid 6-monthly or not (and tamoxifen or anastrozole, in a 2:2 factorial design). In the current retrospective study, we evaluated whether the number of zoledronate infusions actually received had an impact on breast cancer-specific and fragility fracture outcomes. Based on the results of the EBCTCG meta-analysis, we hypothesized that amongst patients who receive less infusions than the planned seven zoledronate infusion in this trial, the number of infusions has no differential effect on these outcomes. Time to event endpoints were analyzed with Cox models and Kaplan Meier curves starting from a 3-year landmark. BMD subset analyses were restricted to patients who participated in the BMD sub-study with available BMD data.

Results: 725 patients who received at least one zoledronate infusion were included in the time-to-event-analysis. There was no statistically significant difference in disease-free survival (adjusted HR 0.83, 95% CI 0.48–1.44, p=0.51) or overall survival (HR 0.97, 95% 0.30-3.11, p=0.96) in patients who received ≤6 zoledronate infusions (n=170) compared to those who received ≥7 zoledronate infusions (n=555) (adjusted HR 0.83, 95% CI 0.48 – 1.44, p=0.51). Both subgroups show stable lumbar spine and total hip BMD measurements across the five years.

Conclusions: Comparable to the metastatic bone disease and fragility fracture settings, there was no evidence observed to indicate that a reduced number of zoledronate infusions is associated with reduced adjuvant efficacy. Further studies to define optimal regimens of adjuvant bone-targeted therapies (prospective evaluation of “how-low-can-you-go”) are required.

Table 1: Multivariate Cox Regression: DFS and OS

Table 2: BMD and percent change from baseline at the total hip and lumbar spine (L1-L4) over 60 months

Citation Format: Ana-Alicia Beltran-Bless, Mark Clemons, Christian Fesl, Dominik Hlauschek, Lidija Soelkner, Gregory R. Pond, Lisa Vandermeer, Richard Greil, Marija Balic, Vesna Bjelic-Radisic, Christian F. Singer, Guenther Steger, Ruth Helfgott, Daniel Egle, Simon P. Gampenrieder, Stephanie Kacerovsky-Strobl, Christoph Suppan, Magdalena Ritter, Gabriel Rinnerthaler, Georg Pfeiler, Hannes Fohler, John Hilton, Michael Gnant. De-escalation of bone-targeted treatment: Does the number of 6-monthly adjuvant zoledronate infusions received affect treatment efficacy for early breast cancer? A sub-study of ABCSG-12 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-02-04.

Abstract HER2-06: HER2-06 Outcome analysis of HER2-zero or HER2-low hormone receptor-positive (HR+) breast cancer patients - characterization of the molecular phenotype in combination with molecular subtyping

Background: Breast cancer with low HER2 expression (HER2-low) is of high clinical relevance because of new therapeutic options with antibody-drug conjugates. We have recently shown in a large cohort from neoadjuvant clinical trials that HER2-low breast cancer has different molecular characteristics as well as different clinical outcomes compared to HER2-zero. Considering the positive correlation between HER2-low expression and hormone receptor positivity observed consistently in many investigations, we have extended our analysis to HR+ tumors from the post-neoadjuvant PenelopeB trial. In PenelopeB, patients with HR+ breast cancer and residual disease after neoadjuvant chemotherapy (NACT) were randomized to post-neoadjuvant palbociclib versus placebo in addition to endocrine therapy. We evaluated the molecular phenotype and clinical outcomes of HER2-low compared to HER2-zero patients. Methods: A total of 1250 patients were randomized, HER2 status was available for 1151 tumors from pretherapeutic core biopsy, determined mainly by local pathology, and from 1213 tumors from the post-NACT sample, determined as part of central pathology. For 1119 patients a paired HER2-status was both available. HER2-zero was defined as IHC0 and HER2-low-positive was defined as IHC1+ or IHC2+/ISH-. Gene expression analysis of 2549 genes using the HTG oncology biomarker panel was performed in 620 pretherapeutic biopsies and 780 post-NACT residual tumor samples, with 539 paired gene expression samples. Breast cancer subtypes were determined using the AIMS approach. Results: In pretherapeutic biopsies, 695 tumors (60%) were HER2-low and 457 (40%) were HER2-zero. A HER2-low status in the biopsy was significantly linked to improved iDFS (HR 0.76 (0.60-0.96; p=0.02). In residual tumors, 632 tumors (60%) were HER2-low and 581 (40%) were HER2-zero, without any prognostic impact of HER2 low status. In addition, a shift of HER2-low-status comparing core biopsy and residual tumor was observed in 415 (37%) of 1119 tumors. 161 (14%) had a shift from HER2-zero to HER2-low and 254 (23%) shifted from HER2-low to HER2-zero. A shift from HER2-zero to HER2-low in the post-NACT samples was significantly linked to reduced iDFS (HR 1.43 [95%CI 1.01-2.01]), p=0.04), compared to HER2-low group, while a shift from HER2-low to HER2-zero was associated with better iDFS compared to HER2-zero group, although not statistically significant (p=0.17). We did not observe a significant correlation of HER2-low status and AIMS molecular subtypes. In particular, the HER2-enriched (HER2E) subtype was assigned to only 4.3% of HER2-zero and 3.1% of HER2-low tumors. Significant iDFS differences were observed for HER2-low-status in combination with AIMS subtypes (lumB/basal/HER2E vs. lumA/normL; overall p-value &lt; 0.0001) for both pretherapeutic biopsies and residual tumor. Patients with post-NACT HER2-low tumors had an improved survival in the subgroups of aggressive AIMS subtypes (lumB/basal/HER2E), but not in the less aggressive AIMs subtypes (lumA/normL), with a positive test for interaction (p=0.02). For the pre-NACT samples a similar, but non-significant trend was observed. We evaluated a total of 620 core biopsies for differences in gene expression comparing HER2-low and HER2-zero tumors. A total of 417 genes were statistically significantly different, but in a hierarchical clustering there was no clear separation of HER2-low and HER2-zero tumors. Conclusions: In the PenelopeB cohort of HR+ tumors, a HER2-low status in pretherapeutic core biopsies is related to improved disease-free survival, especially for those tumors that have a more aggressive intrinsic subtype. A shift of HER2-low status was observed before and after chemotherapy, indicating an adaptation of the pathway activity to therapy-induced stress, which might become relevant for future diagnostic and therapeutic approaches.

Citation Format: Carsten Denkert, Miguel Martín, Michael Untch, Hervé R. Bonnefoi, Erik S. Knudsen, Seock-Ah Im, Angela DeMichele, Agnieszka Witkiewicz, Laura Van ’t Veer, Sung-Bae Kim, Harry D. Bear, Nicole McCarthy, Karen Gelmon, Frederik Marmé, José Ángel García-Sáenz, Nicholas Turner, Federico Rojo, Martin Filipits, Lesley-Ann Martin, Peter A. Fasching, Christian Schem, Catherine M. Kelly, Toralf Reimer, Masakazu Toi, Hope Rugo, Michael Gnant, Andreas Makris, Yuan Liu, Karsten Weber, Sivaramakrishna Rachakonda, Sibylle Loibl. HER2-06 Outcome analysis of HER2-zero or HER2-low hormone receptor-positive (HR+) breast cancer patients - characterization of the molecular phenotype in combination with molecular subtyping [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr HER2-06.

Abstract PD17-06: Immunohistochemical markers and determinants of clinical response in the Penelope-B trial

Background: The Penelope-B trial did not show improvement in invasive disease-free survival (iDFS) with the addition of palbociclib to endocrine therapy (ET) in patients with high-risk early breast cancer (BC) after neoadjuvant chemotherapy (NACT). Biomarkers may be able to identify subgroups of patients deriving benefit from Palbociclib and guide future studies. Estrogen-receptor (ER), progesterone-receptor (PgR) and Ki-67 might be helpful in identifying patients benefiting from palbociclib. Concordantly, tumors with elevated expression of Cyclin D1 and phosphorylated retinoblastoma protein (phospho-RB) may harbor more dependency on CDK4/6 and thus higher sensitivity to palbociclib. Methods: The percentage of positive ER and PgR cells and Ki-67 assessed in surgical specimens after NACT were combined to obtain the immunohistochemical score 3 (IHC3, Cuzick et al JCO 2011, low vs high based on the median IHC3 value). Cyclin D1 and phospho-RB Ser 807/811 immunoreactive (phospho-RB) scores were analyzed in residual tumors after NACT (range 0-12 each). Proportional hazard regression model was used to assess the predictive and prognostic value of IHC3 and treatment on iDFS. Subgroup analysis was performed according to BC intrinsic subtypes (luminal-A/normal-like, luminal-B/HER2-enriched/basal) and HER2-status (HER2 0, HER2 low). Cox/Fine-Gray regression was used to define the predictive and prognostic value of CyclinD1 (≤1, &gt;1), phospho-RB (≤2, &gt;2) as dichotomized and continuous variables on iDFS, distant DFS (DDFS), locoregional invasive recurrence-free interval (LRRFI) and overall survival (OS). Multivariate analyses (MVA) were adjusted for age (≤50 vs &gt;50), Ki-67 (≤15 vs &gt;15), region (non-Asian vs Asian), ypN (ypN0-1 vs ypN2-3), risk status (CPS-EG=2 ypN+ vs ≥3), cT (cT1-2 vs cT3-4), ypT (ypT0-2 vs ypT3-4), and grade (G1-2 vs G3). The MVA for IHC3 includes all the covariates above except Ki-67. p&lt; 0.05 was defined as statistically significant. Results: Data for ER, PgR, Ki-67, HER2, Cyclin D1 and phospho-RB were available for 1250 patients. Overall, 98.9% of the patients had ER+ tumors, 75.0% PgR+, 52.2% had HER2 low, 25.5% Ki-67&gt;15, 50% had IHC3 score higher than median, 93.9% had Cyclin D1 &gt;1, 57.8% had phospho-RB &gt;2. Patients with IHC3 score high had a worse iDFS compared to patients with IHC3 score low (MVA HR 2.28 95%CI (1.78-2.91), p&lt; 0.0001). Patients with luminal-A/normal-like tumors and IHC3 low had an improved iDFS with the addition of palbociclib to ET (MVA HR 0.35 95%CI (0.14-0.90), test for interaction p=0.01). No difference was observed according to HER2 status. Cyclin D1&gt;1 has no predictive value but is prognostic for better iDFS (MVA HR 0.62 95%CI (0.41-0.94), p=0.023), LRRFI (MVA HR 0.30 95%CI (0.15-0.63), p=0.001) and OS (MVA HR 0.50 95%CI (0.28-0.89), p=0.019). Similar results were obtained when Cyclin D1 was analysed as a continuous variable. Phospho-RB had neither predictive nor prognostic value. Phospho-RB highly correlates with Ki-67 (p&lt; 0.001, Spearman correlation 0.248). Conclusions: Patients with high Cyclin D1 expression had a favorable prognosis independent of treatment arm, but patients with luminal-A/normal-like tumors and IHC3 low after NACT had an improved outcome when receiving palbociclib in addition to adjuvant ET. Theses exploratory studies suggest specific signatures/phenotypes could predict benefit from Palbociclib in high-risk early breast cancer.

Citation Format: Erik S. Knudsen, Sivaramakrishna Rachakonda, Frederik Marmé, Miguel Martín, Michael Untch, Hervé R. Bonnefoi, Wolfgang D. Schmitt, Sung-Bae Kim, Harry D. Bear, Agnieszka Witkiewicz, Seock-Ah Im, Angela DeMichele, Laura Van’t Veer, Nicole McCarthy, Bruno V. Sinn, Karen Gelmon, José Ángel García-Sáenz, Catherine M. Kelly, Toralf Reimer, Nicholas Turner, Federico Rojo, Martin Filipits, Peter A. Fasching, Christian Schem, Lesley-Ann Martin, Yuan Liu, Masakazu Toi, Hope Rugo, Michael Gnant, Andreas Makris, Jenny Furlanetto, Karsten Weber, Carsten Denkert, Sibylle Loibl. Immunohistochemical markers and determinants of clinical response in the Penelope-B trial [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD17-06.

PROCURE European consensus on breast cancer multigene signatures in early breast cancer management

Breast cancer multigene signatures (BCMS) have changed how patients with early-stage breast cancer (eBC) are managed, as they provide prognostic information and can be used to select patients who may avoid adjuvant chemotherapy. Clinical guidelines make recommendations on the use of BCMS; however, little is known on the current use of BCMS in clinical practice. We conduct a two-round Delphi survey to enquire about current use and perceived utility for specific patient profiles, and unmet needs of BCMS. Overall, 133 panellists experienced in breast cancer across 11 European countries have participated, most using BCMS either routinely (66.2%) or in selected cases (27.1%). Our results show that BCMS are mainly used to assess the risk of recurrence and to select patients for adjuvant chemotherapy; notably, no consensus has been reached on the lack of utility of BCMS for selecting the type of chemotherapy to administer. Also, there are discrepancies between the recommended and current use of BCMS in clinical practice, with use in certain patient profiles for which there is no supporting evidence. Our study suggests that physician education initiatives are needed to ensure the correct use and interpretation of BCMS to, ultimately, improve management of patients with eBC.

Overall survival with neratinib after trastuzumab-based adjuvant therapy in HER2-positive breast cancer (ExteNET): A randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

ExteNET showed that neratinib, an irreversible pan-HER tyrosine kinase inhibitor, given for 1 year after trastuzumab-based therapy significantly improved invasive disease-free survival in women with early-stage HER2-positive breast cancer. We report the final analysis of overall survival in ExteNET.

METHODS

In this international, randomised, double-blind, placebo-controlled, phase 3 trial, women aged 18 years or older with stage 1-3c (amended to stage 2-3c) HER2-positive breast cancer who had completed neoadjuvant and adjuvant chemotherapy plus trastuzumab were eligible. Patients were randomly assigned to oral neratinib 240 mg/day or placebo for 1 year. Randomisation was stratified according to hormone receptor (HR) status (HR-positive vs. HR-negative), nodal status (0, 1-3 or 4+), and trastuzumab regimen (sequentially vs. concurrently with chemotherapy). Overall survival was analysed by intention to treat. ExteNET is registered (Clinicaltrials.gov: NCT00878709) and is complete.

RESULTS

Between July 9, 2009, and October 24, 2011, 2840 women received neratinib (n = 1420) or placebo (n = 1420). After a median follow-up of 8.1 (IQR, 7.0-8.8) years, 127 patients (8.9%) in the neratinib group and 137 patients (9.6%) in the placebo group in the intention-to-treat population had died. Eight-year overall survival rates were 90.1% (95% CI 88.3-91.6) with neratinib and 90.2% (95% CI 88.4-91.7) with placebo (stratified hazard ratio 0.95; 95% CI 0.75-1.21; p = 0.6914).

CONCLUSIONS

Overall survival in the extended adjuvant setting was comparable for neratinib and placebo after a median follow-up of 8.1 years in women with early-stage HER2-positive breast cancer.

Does the number of 6-monthly adjuvant zoledronate infusions received affect treatment efficacy for early breast cancer? A sub-study of ABCSG-12

BACKGROUND

The widespread adoption of adjuvant bisphosphonate therapy for postmenopausal early breast cancer (EBC) patients was based on results of the Early Breast Cancer Trialist Group (EBCTCG) meta-analysis. Despite multiple regimens evaluated, there was no signal of varying efficacy with type, dose/dose intensity of bisphosphonate administration. We evaluated the effect of early treatment cessation using long-term outcome data from the ABCSG-12 trial.

PATIENTS AND METHODS

ABCSG-12 randomized 1803 hormone-receptor positive EBC patients on ovarian suppression between 1999 and 2006 to receive 4 mg zoledronic acid 6-monthly or not (and tamoxifen or anastrozole, 2:2 factorial design). In the current study, we evaluated whether the number of zoledronate infusions had an impact on breast cancer-specific outcomes. We hypothesized that amongst patients who received at least one zoledronate infusion, the number of infusions had no effect on outcomes. Time-to-event endpoints were analysed with Cox models and Kaplan Meier curves starting from a 3-year landmark. BMD analysis was restricted to patients who participated in the BMD sub-study.

RESULTS

725 patients who received at least one zoledronate infusion were included in the time-to-event analysis. There was no statistically significant difference in disease-free or overall survival in the patients who received ≤6 zoledronate infusions (n = 170) compared to those who received ≥7 zoledronate infusions (n = 555).

CONCLUSIONS

Comparable to efforts to de-escalate treatment duration in metastatic bone disease, there was no evidence to indicate that a reduced number of zoledronate infusions is associated with reduced adjuvant efficacy. Further studies to define optimal regimens of adjuvant bone-targeted therapies are required.

Long-Term Outcomes of Adjuvant Denosumab in Breast Cancer

Outcomes of Adjuvant Denosumab in Breast CancerIn this long-term report of a prospective, double-blind, placebo-controlled, phase 3 trial of adjuvant aromatase inhibitor in postmenopausal patients with early hormone receptor-positive breast cancer, adjuvant denosumab therapy improved disease-free survival by 3.5 percentage points, bone metastasis-free survival by 2.5 percentage points, and overall survival by 1.0 percentage point at 9 years of follow-up.

Breast surgery after neoadjuvant therapy

PURPOSE OF REVIEW

The standard of care in breast surgery has changed, from mastectomy to breast conserving surgery whenever possible, and from axillary dissection to sentinel node biopsy. Neoadjuvant systemic approaches have broadened the indications for organ-conserving and less mutilating surgery, but also raise important questions of balancing locoregional treatment de-escalation and protecting excellent long-term outcomes.

RECENT FINDINGS

Recent studies have aimed at investigating the safety of de-escalating surgical approaches not only in the upfront breast surgery situation but also after neoadjuvant systemic therapy. This pertains to both the safety of breast conserving surgery - including more complex oncoplastic approaches - within the new (posttherapeutic) anatomical extent of the residual disease, but more controversially to de-escalating surgical treatment of the axilla. While sentinel node biopsy appears to be the standard of care for node-negative disease also after primary systemic therapy, the optimal procedure in situations of posttherapeutic node-positive disease remains highly controversial.

SUMMARY

Both breast and axillary surgery after neoadjuvant systemic therapy for women with breast cancer has undergone multiple paradigm changes in recent years. For the primary tumor in the breast, breast-conserving surgery constitutes the standard of care, and unnecessary mastectomies should be strongly discouraged. For axillary surgery, sentinel-node biopsy should be aimed at, and completion axillary dissections minimized for situations of extensive disease and or poor neoadjuvant treatment response. Additional techniques such as targeted axillary dissection are currently under evaluation in clinical trials.

Adjuvant palbociclib for ER+ breast cancer (PALLAS Trial (ABCSG-42/AFT-05/PrE0109/BIG-14-13): A preplanned analysis of the stage IIA cohort

390216

Background: CDK4/6 inhibitors have become standard of care for advanced hormone receptor positive, HER2-negative (HR+/HER2-) breast cancer in combination with endocrine therapy (ET), with one approved for high-risk patients (pts) in the adjuvant setting. The PALLAS Trial investigated the addition of palbociclib to adjuvant ET in pts with stage II-III breast cancer. Stage IIA patients were specifically enrolled to evaluate the potential benefit of using palbociclib with adjuvant ET pts diagnosed at lower risk who may have more indolent disease. Methods: In the prospective, randomized, phase III PALLAS trial, pts with HR+/HER2- early breast cancer were randomly assigned to receive adjuvant ET for at least 5 years with or without 2 years of palbociclib (125 mg orally once daily, days 1-21 of a 28-day cycle). ET was of provider’s choice. Stage IIA enrollment was capped at 1,000 patients. While the primary end point of the overall study was invasive disease-free survival (iDFS) for the entire cohort, there was a preplanned analysis of recurrence and survival endpoints in the stage IIA cohort. Outcomes were compared between arms using stratified log-rank tests and Cox models (stratification factors: chemotherapy and age ≤ 50). Results: Among 5,796 pts enrolled at 406 centers in 21 countries worldwide between 9/1/2015 and 11/30/2018, a total of 1,010 stage IIA pts were enrolled. The protocol-defined number of events occurred at a median follow-up of 50 months for this subgroup (43.1 months for the overall study). Median age within this subgroup was 54 (range 29-85 yrs), and 410 (40.6%) were pre/perimenopausal, 506 (50.1%) T2/N0 (vs T0-1/N1), 272 (26.9%) grade 3 (vs. grade1/2), and 561 (55.5%) received chemotherapy. iDFS events occurred in 31 of 503 (6.2%) pts who received palbociclib plus ET and in 45 of 507 (8.9%) pts who received ET alone, resulting in a statistically nonsignificant difference in iDFS at 4 years (92.9% vs. 92.1%; hazard ratio, 0.75; CI, 0.48 to 1.19; P = .23). Nonsignificant differences were also observed for invasive breast cancer-free, distant recurrence-free, and locoregional cancer-free survival. No significant differences in iDFS were observed in subgroups including age group, receipt of chemotherapy, tumor grade, and clinical risk (T1/N1 vs. T2/N0).Conclusions: In this preplanned analysis of the stage IIA cohort of the PALLAS trial, the addition of adjuvant palbociclib to standard ET did not improve outcomes over ET alone, suggesting no benefit from the agent in reducing the incidence of early relapse in pts with lower-stage HR+/HER2- breast cancer. Future analyses will incorporate genomic risk and other molecular patterns from the extensive transPALLAS correlative program. Additional follow-up (10-year minimum) is also underway to assess the impact of palbociclib exposure on late recurrence in HR+ disease. Clinical trial information: NCT02513394.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Austrian treatment algorithms in HER2-positive metastatic breast cancer: a 2022 update

In the past 12 months a plethora of relevant novel data for the treatment of metastatic HER2 positive breast cancer were published. To bring this new evidence into a clinical perspective, a group of Austrian breast cancer specialists updated their previously published treatment algorithm for those patients. For this consensus paper a total of eight scenarios were developed in which treatment strategies appropriate for specific patient profiles were evaluated. Consensus was established by detailed discussions of each scenario and by reaching full consensus.

Estrogen Receptor Alpha Gene Amplification Is an Independent Predictor of Long-Term Outcome in Postmenopausal Patients with Endocrine-Responsive Early Breast Cancer

PURPOSE

Estrogen receptor (ER) expression is a prognostic parameter in breast cancer, and a prerequisite for the use of endocrine therapy. In ER+ early breast cancer, however, no receptor-associated biomarker exists that identifies patients with a particularly favorable outcome. We have investigated the value of ESR1 amplification in predicting the long-term clinical outcome in tamoxifen-treated postmenopausal women with endocrine-responsive breast cancer.

EXPERIMENTAL DESIGN

394 patients who had been randomized into the tamoxifen-only arm of the prospective randomized ABCSG-06 trial of adjuvant endocrine therapy with available formalin-fixed, paraffin-embedded tumor tissue were included in this analysis. IHC ERα expression was evaluated both locally and in a central lab using the Allred score, while ESR1 gene amplification was evaluated by FISH analysis using the ESR1/CEP6 ratio indicating focal copy number alterations.

RESULTS

Focal ESR1 copy-number elevations (amplifications) were detected in 187 of 394 (47%) tumor specimens, and were associated with a favorable outcome: After a median follow-up of 10 years, women with intratumoral focal ESR1 amplification had a significantly longer distant recurrence-free survival [adjusted HR, 0.48; 95% confidence interval (CI), 0.26-0.91; P = 0.02] and breast cancer-specific survival (adjusted HR 0.47; 95% CI, 0.27-0.80; P = 0.01) as compared with women without ESR1 amplification. IHC ERα protein expression, evaluated by Allred score, correlated significantly with focal ESR1 amplification (P < 0.0001; χ2 test), but was not prognostic by itself.

CONCLUSIONS

Focal ESR1 amplification is an independent and powerful predictor for long-term distant recurrence-free and breast cancer-specific survival in postmenopausal women with endocrine-responsive early-stage breast cancer who received tamoxifen for 5 years.

Cost-effectiveness of palbociclib in early breast cancer patients with a high risk of relapse: Results from the PENELOPE-B trial

Background

Patients with hormone receptor-positive, HER2-negative breast cancer who have residual invasive disease after neoadjuvant chemotherapy (NACT) are at a high risk of relapse. PENELOPE-B was a double-blind, placebo-controlled, phase III trial that investigated adding palbociclib (PAL) for thirteen 28-day cycles to adjuvant endocrine therapy (ET) in these patients. Clinical results showed no significant improvement in invasive disease-free survival with PAL.

Methods

We performed a pre-planned cost-effectiveness analysis of PAL within PENELOPE-B from the perspective of the German statutory health insurance. Health-related quality of life scores, collected in the trial using the EQ-5D-3L instrument, were converted to utilities based on the German valuation algorithm. Resource use was valued using German price weights. Outcomes were discounted at 3% and modeled with mixed-level linear models to adjust for attrition, repeated measurements, and residual baseline imbalances. Subgroup analyses were performed for key prognostic risk factors. Scenario analyses addressed data limitations and evaluated the robustness of the estimated cost-effectiveness of PAL to methodological choices.

Results

The effects of PAL on quality-adjusted life years (QALYs) were marginal during the active treatment phase, increasing thereafter to 0.088 (95% confidence interval: −0.001; 0.177) QALYs gained over the 4 years of follow-up. The incremental costs were dominated by PAL averaging EUR 33,000 per patient; costs were higher in the PAL arm but not significantly different after the second year. At an incremental cost-effectiveness ratio of EUR 380,000 per QALY gained, PAL was not cost-effective compared to the standard-of-care ET. Analyses restricted to Germany and other subgroups were consistent with the main results. Findings were robust in the scenarios evaluated.

Conclusions

One year of PAL added to ET is not cost-effective in women with residual invasive disease after NACT in Germany.

Oncoplastic breast consortium recommendations for mastectomy and whole breast reconstruction in the setting of post-mastectomy radiation therapy

Aim

Demand for nipple- and skin- sparing mastectomy (NSM/SSM) with immediate breast reconstruction (BR) has increased at the same time as indications for post-mastectomy radiation therapy (PMRT) have broadened. The aim of the Oncoplastic Breast Consortium initiative was to address relevant questions arising with this clinically challenging scenario.

Methods

A large global panel of oncologic, oncoplastic and reconstructive breast surgeons, patient advocates and radiation oncologists developed recommendations for clinical practice in an iterative process based on the principles of Delphi methodology.

Results

The panel agreed that surgical technique for NSM/SSM should not be formally modified when PMRT is planned with preference for autologous over implant-based BR due to lower risk of long-term complications and support for immediate and delayed-immediate reconstructive approaches. Nevertheless, it was strongly believed that PMRT is not an absolute contraindication for implant-based or other types of BR, but no specific recommendations regarding implant positioning, use of mesh or timing were made due to absence of high-quality evidence. The panel endorsed use of patient-reported outcomes in clinical practice. It was acknowledged that the shape and size of reconstructed breasts can hinder radiotherapy planning and attention to details of PMRT techniques is important in determining aesthetic outcomes after immediate BR.

Conclusions

The panel endorsed the need for prospective, ideally randomised phase III studies and for surgical and radiation oncology teams to work together for determination of optimal sequencing and techniques for PMRT for each patient in the context of BR

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Autologous breast reconstruction is increasingly preferred over implants in the setting of radiation therapy.

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Use of patient-reported outcomes is endorsed.

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Shape and size of reconstructed breasts can hinder radiotherapy planning.

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There is a need for randomised phase III trials.

Long-term outcomes of adjuvant denosumab in breast cancer: Fracture reduction and survival results from 3,425 patients in the randomised, double-blind, placebo-controlled ABCSG-18 trial

507

Background: State-of-the-art adjuvant endocrine therapy with aromatase inhibitors (AI) compromises bone health in postmenopausal patients with hormone receptor-positive (HR+) breast cancer, increasing fracture incidence. Adjuvant treatment with the anti-RANK ligand denosumab (Dmab) counteracts these side effects and may improve outcomes. We here report the final long-term outcomes of the ABCSG-18 trial (ClinicalTrials.gov NCT00556374). Methods: In this prospective, double-blind, placebo-controlled, phase 3 trial, 3,425 postmenopausal patients with early HR+ breast cancer on AI therapy were randomised in 58 trial centers between 2006 and 2013 to receive either Dmab 60 mg or placebo s.c. every 6 months (q6m). The primary endpoint was time to first clinical fracture, secondary disease outcome-related endpoints were disease-free survival (DFS), bone-metastasis free survival (BMFS), and overall survival (OS). In addition to the main endpoint analyses reported previously, exploratory long-term follow-up was conducted in ABCSG-18. Main time-to-event analyses were based on stratified Cox models. Sensitivity analyses accounting for treatment cross-over associated with a late Dmab open-label phase, as well as for receiving any anti-resorptive agents were performed. Results: For this final protocol-defined analysis, median follow-up is 8 years (Q1,3: 6, 9.6), and all patients had ended their randomly assigned double-blind treatment (Dmab 60mg s.c. q6m n = 1711; placebo s.c. q6m n = 1709) for a median of 5 years. DFS was improved in the Dmab group versus the placebo group (309 versus 368 DFS events, hazard ratio (HR) 0.83, 95% CI 0.71-0.97, p = 0.016), resulting in an absolute 9-year DFS difference of 3.5% (79.4% vs 75.9%, respectively). When censoring for late cross-over and use of anti-resorptive agents, the DFS difference was confirmed (HR 0.82, p = 0.010). BMFS was improved by 19 per cent (HR 0.81, 95% CI 0.65-1.00, p = 0.047) in the Dmab group, and OS was improved by 20 per cent in the uncensored analysis (127 versus 158 OS events, HR 0.80, 95% CI 0.64-1.01, p = 0.065), and 26 per cent after censoring (HR 0.74, 95% CI 0.58-0.94, p = 0.013). The previously reported marked reduction in clinical fractures persisted even long-term, with 201 fractures in the Dmab and 255 fractures in the placebo group (HR 0.76, 95% CI 0.63-0.92, p = 0.004). No new toxicities for this (low) bone-protective dose of adjuvant Dmab were reported, particularly no ONJ occured.. Conclusions: Adjuvant Dmab 60mg every 6 months during AI therapy is safe, and markedly reduces treatment-induced clinical fractures even in the long-term. DFS, BMFS, and OS are improved in this descriptive final long-term analysis of ABCSG-18. Adjuvant denosumab should be considered for routine clinical use in postmenopausal patients with HR+ breast cancer. Clinical trial information: NCT00556374.

Consensus on the utility of breast cancer multigene signatures in routine clinical practice: Results of the PROCURE Project

e13639

Background: Several Breast Cancer Multigene Signatures (BCMS) are available to profile early breast cancer (eBC) that according to current evidence, can provide reliable information on the risk of recurrence but the knowledge regarding their real use in clinical practice is scarce. The PROCURE Project aims to establish recommendations on the use of BCMS in clinical practice. Methods: A Scientific Committee consisting of 8 European experts in BC, including oncologists, pathologists, and surgeons, developed a Delphi questionnaire that was administered twice to clinicians across different European centers. The questionnaire included 5 sections: 1) Panelists’ profile and experience with BCMS, 2) Current clinical practice in eBC and use of BCMS, 3) Panelists’ opinion on the utility of the BCMS in eBC according to patient profiles, 4) Agreement with a set of recommendations on the use of BCMS in clinical practice and 5) Identification of unmet needs and future applications of BCMS. 70% agreement was used to determine consensus on a topic. Results: 133 panelists from 11 European countries completed both rounds of the survey. Most of the panelists worked in a teaching hospital (86.5%) and 72.2% of them were medical oncologists. 93.6% of the panelists used BCMS routinely or in selected patients and 73.4% had more than 5 years of experience using BCMS. According to panelists, for being useful in clinical practice BCMS should consider clinical and pathological features of the disease (91%). Additionally, BCMS must provide both, prognostic and predictive information (82%), and information on the risk of late distant recurrence from 5 to 10 years (74%), all based on prospective randomized clinical trials (85%). BCMS must also provide accurate results to guide adjuvant chemotherapy decision (81%). Regarding recommendations for improving BCMS utility, 76% of the panelists agreed that hospitals policies on the use of BCMS must be based on clinical practice guidelines. Panelists also agreed that patients should have the right to access their BCMS results to take part in the treatment decision (86%) and more training is needed for patients (79%) as well as oncologists (84%) and pathologists (82%). Finally, panelists mostly disagree on the fact that BCMS must be performed in all patients when BC is suspected (76%). Conclusions: The high degree of importance that panelists attributed to the fact that a BCMS should provide both prognostic and predictive information, reflects a misconception on the utility of BCMS as they are primarily prognostic tools but not predictive about the effect of a therapeutic intervention. Also, consensus reached on the need of providing risk of late recurrence from 5 to 10 years shows that panelists evaluate the long-term treatment even in the early setting.

Impact of body mass index on treatment and outcomes in patients with early hormone receptor-positive breast cancer receiving endocrine therapy with or without palbociclib in the PALLAS trial

518

Background: Body Mass Index (BMI) impacts breast cancer risk and prognosis. Conflicting results have been published regarding BMI as a predictive factor for endocrine therapy benefit. CDK4/6 inhibitors (CDK4/6i) in combination with endocrine treatment (ET) are standard-of-care treatments for metastatic hormone receptor-positive breast cancer. In contrast to cytotoxic chemotherapy, CDK4/6i are given at a fixed dose irrespective of BMI or weight. The PALLAS trial compared the combination of the CDK4/6i palbociclib and adjuvant ET to ET alone in the early breast cancer setting. This analysis investigates the impact of BMI on the efficacy and the side effect profile of palbociclib (P) in the PALLAS trial. Methods: In this pre-planned analysis, patients (pts) enrolled in PALLAS were categorized according to BMI as underweight (BMI <18.5 kg/m2), normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25-29.9 kg/m2) and obese (³30 kg/m2), respectively. Adverse event differences were assessed with Chi-squared tests. Time to early discontinuation of P was analyzed with Fine and Gray competing risk models. Cox models were used to investigate the association between BMI category and time to invasive disease-free survival (iDFS). Results: Of a total of 5698 pts included in this analysis, 68 (1.2%) were underweight, 2082 (36.5%) normal weight, 1818 (31.9%) overweight and 1730 (30.4%) obese at baseline. Significantly different rates of all grade neutropenia were observed in normal weight, overweight and obese pts with regard to total (88.5%, 85.7% and 74.7%), as well as grade 3 (64.1%, 62.0% and 43.9%) and grade 4 neutropenia (7.0%, 3.6% and 2.0%), respectively. The lower frequency and severity of neutropenia observed in overweight and obese pts was associated with a significant lower treatment discontinuation rate over time when compared to normal weight patients (overweight vs normal weight: HR 0.73 CI 0.63-0.84, p<0.0001, and obese vs normal weight: HR 0.65 CI 0.56-0.75, p<0.0001). In pts treated with P, neutropenia was the primary toxicity leading to treatment discontinuation in 21.1% of normal weight pts, 14.0% of overweight pts and 5.9% obese pts, respectively. Despite these observations, there was no statistically significant improvement in iDFS with the addition of P to ET in any weight category (normal weight HR 0.84 CI 0.63-1.12, overweight HR 1.10 CI 0.82-1.49 and obese HR 0.95 CI 0.69-1.30). Conclusions: This pre-planned analysis of outcomes by BMI in the PALLAS trial demonstrates significantly less frequent and less severe neutropenia in overweight and obese pts compared to those with normal weight, leading to significant lower treatment discontinuation rates. However, no difference in iDFS outcomes by BMI was observed. Additional long-term follow-up will further evaluate whether BMI ultimately impacts outcome. Clinical trial information: NCT02513394.

A phase 3 study to determine the breast cancer risk reducing effect of denosumab in women carrying a germline BRCA1 mutation (BRCA-P Study)

TPS10616

Background: Women with BRCA1 mutations have a 50-70% lifetime risk of developing breast cancer. Currently, prophylactic mastectomy is the only strategy that significantly reduces breast cancer risk. Recent evidence suggests that the RANK/RANKL signaling pathway plays a pivotal role in the development of BRCA1-mutated tumors. Targeting the RANK pathway has been shown to attenuate breast epithelial proliferation in vitro and in vivo, and to profoundly reduce mammary tumor formation in mouse models. The RANKL inhibitor, denosumab, an FDA approved drug for the treatment of osteoporosis, is potentially an ideal chemopreventive agent for women with a germline BRCA1 mutation because it: (a) could potentially reduce breast cancer risk, and (b) concomitantly protect bone health in women who have already undergone bilateral salpingo-oophorectomy or in naturally postmenopausal women. The BRCA-P study will evaluate the reduction in the risk of any breast cancer (invasive or DCIS) in women with a germline BRCA1 mutation who are treated with denosumab compared to placebo. Sub-studies include measurement of bone turnover markers; epigenetic profiling of tumor tissues; measuring denosumab’s effect on bone and breast density; measurement of serum RANK, RANKL, OPG, progesterone, LH and FSH; and measurement of quality of life. Methods: This is a randomized, double-blind, placebo-controlled, multi-center international phase 3 study to determine the breast cancer risk reducing effect of denosumab in women carrying a germline BRCA1 mutation. Eligibility: Women with a confirmed BRCA1 germline mutation; ages ≥ 25 years and ≤ 55 years; no evidence of breast or ovarian cancer; no preventive breast surgery planned at randomization; ECOG performance status 0-1. Eligible participants will be randomized 1:1 to receive 120 mg of subcutaneous denosumab or placebo every 6 months for 5 years. Thereafter, all participants will be followed up for 5 years. Primary endpoints: Time to the occurrence of any breast cancer (invasive or DCIS). Secondary endpoints: Time to invasive triple negative breast cancer; time to other BRCA1 mutation associated malignancies, time to clinical fractures. Statistically, a 35% reduction in breast cancer risk would be detected with an 80% power and a two-sided significance level of 5% if 167 breast cancer cases are observed. We expect to observe the number of events needed if 1459 subjects per group (2918 in total) are randomized. The study is currently enrolling participants in Austria, Australia, Israel and Spain. The study will shortly begin accrual in Germany, United Kingdom, and at more than 30 sites across the United States. Globally, the trial is coordinated by the Austrian Breast & Colorectal Cancer Study Group and by the Alliance for Clinical Trial in Oncology in the US. EudraCT: 2017-02505-35. Clinical trial information: NCT04711109.

Effect of concomitant statin treatment in postmenopausal patients with hormone receptor-positive early-stage breast cancer receiving adjuvant denosumab or placebo: a post hoc analysis of ABCSG-18

Background

Statins are cholesterol-lowering drugs prescribed for the prevention and treatment of cardiovascular disease. Moreover, statins may possess anticancer properties and interact with receptor activator of nuclear factor κB ligand expression. We aimed at evaluating a hypothetical synergistic effect of statins with denosumab in early-stage breast cancer (BC) patients from the Austrian Breast and Colorectal Cancer Study Group (ABCSG) trial 18.

Patients and methods

ABCSG-18 (NCT00556374) is a prospective, randomized, double-blind, phase III study; postmenopausal patients with hormone receptor-positive BC receiving a nonsteroidal aromatase inhibitor were randomly assigned to denosumab or placebo. In this post hoc analysis, we investigated the effects of concomitant statin therapy on recurrence risk (RR) of BC, fracture risk and bone mineral density (BMD).

Results

In the study population (n = 3420), statin therapy (n = 824) was associated with worse disease-free survival (DFS) [hazard ratio (HR) 1.35, 95% confidence interval (CI) 1.04-1.75; P = 0.023]. While no significant effect of lipophilic statins (n = 710) on RR was observed (HR 1.30, 95% CI 0.99-1.72; P = 0.062), patients on hydrophilic statins (n = 87) had worse DFS compared with patients not receiving any statins (HR 2.00, 95% CI 1.09-3.66; P = 0.026). This finding was mainly driven by the effect of hydrophilic statins on DFS in the denosumab arm (HR 2.63, 95% CI 1.21-5.68; P = 0.014). However, this effect subsided after correction for confounders in the sensitivity analysis. No association between statin use and fracture risk or osteoporosis was observed.

Conclusion

According to this analysis, hydrophilic statins showed a detrimental effect on DFS in the main model, which was attenuated after correction for confounders. Our data need to be interpreted with caution due to their retrospective nature and the low number of patients receiving hydrophilic statins.

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Statin co-medication was initially associated with a worse DFS in hormone receptor-positive early-stage BC patients.

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This effect was mainly driven by patients on hydrophilic statins.

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However, this effect subsided after correction for confounders in the sensitivity analysis.

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No association between statin use and fracture risk or osteoporosis was observed.

Aromatase inhibitors versus tamoxifen in premenopausal women with oestrogen receptor-positive early-stage breast cancer treated with ovarian suppression: a patient-level meta-analysis of 7030 women from four randomised trials

BACKGROUND

For women with early-stage oestrogen receptor (ER)-positive breast cancer, adjuvant tamoxifen reduces 15-year breast cancer mortality by a third. Aromatase inhibitors are more effective than tamoxifen in postmenopausal women but are ineffective in premenopausal women when used without ovarian suppression. We aimed to investigate whether premenopausal women treated with ovarian suppression benefit from aromatase inhibitors.

METHODS

We did a meta-analysis of individual patient data from randomised trials comparing aromatase inhibitors (anastrozole, exemestane, or letrozole) versus tamoxifen for 3 or 5 years in premenopausal women with ER-positive breast cancer receiving ovarian suppression (goserelin or triptorelin) or ablation. We collected data on baseline characteristics, dates and sites of any breast cancer recurrence or second primary cancer, and dates and causes of death. Primary outcomes were breast cancer recurrence (distant, locoregional, or contralateral), breast cancer mortality, death without recurrence, and all-cause mortality. As distant recurrence invariably results in death from breast cancer several years after the occurrence, whereas locoregional recurrence and new contralateral breast cancer are not usually fatal, the distant recurrence analysis is shown separately. Standard intention-to-treat log-rank analyses estimated first-event rate ratios (RR) and their confidence intervals (CIs).

FINDINGS

We obtained data from all four identified trials (ABCSG XII, SOFT, TEXT, and HOBOE trials), which included 7030 women with ER-positive tumours enrolled between June 17, 1999, and Aug 4, 2015. Median follow-up was 8·0 years (IQR 6·1-9·3). The rate of breast cancer recurrence was lower for women allocated to an aromatase inhibitor than for women assigned to tamoxifen (RR 0·79, 95% CI 0·69-0·90, p=0·0005). The main benefit was seen in years 0-4 (RR 0·68, 99% CI 0·55-0·85; p<0·0001), the period when treatments differed, with a 3·2% (95% CI 1·8-4·5) absolute reduction in 5-year recurrence risk (6·9% vs 10·1%). There was no further benefit, or loss of benefit, in years 5-9 (RR 0·98, 99% CI 0·73-1·33, p=0·89) or beyond year 10. Distant recurrence was reduced with aromatase inhibitor (RR 0·83, 95% CI 0·71-0·97; p=0·018). No significant differences were observed between treatments for breast cancer mortality (RR 1·01, 95% CI 0·82-1·24; p=0·94), death without recurrence (1·30, 0·75-2·25; p=0·34), or all-cause mortality (1·04, 0·86-1·27; p=0·68). There were more bone fractures with aromatase inhibitor than with tamoxifen (227 [6·4%] of 3528 women allocated to an aromatase inhibitor vs 180 [5·1%] of 3502 women allocated to tamoxifen; RR 1·27 [95% CI 1·04-1·54]; p=0·017). Non-breast cancer deaths (30 [0·9%] vs 24 [0·7%]; 1·30 [0·75-2·25]; p=0·36) and endometrial cancer (seven [0·2%] vs 15 [0·3%]; 0·52 [0·22-1·23]; p=0·14) were rare.

INTERPRETATION

Using an aromatase inhibitor rather than tamoxifen in premenopausal women receiving ovarian suppression reduces the risk of breast cancer recurrence. Longer follow-up is needed to assess any impact on breast cancer mortality.

FUNDING

Cancer Research UK, UK Medical Research Council.

Abstract P1-15-01: Effect of concomitant statin treatment in postmenopausal patients with hormone-receptor positive early-stage breast cancer receiving adjuvant denosumab or placebo: A post-hoc analysis of ABCSG-18

Background Statins are a common class of cholesterol-lowering drugs prescribed for the prevention and treatment of cardiovascular disease. Moreover, it was suggested that statins may possess anti-cancer properties and interact with RANK ligand expression. Therefore, we aimed at evaluating a hypothetical synergistic effect of statins with denosumab in early-stage breast cancer (BC) patients from the Austrian Breast and Colorectal Cancer Study Group (ABCSG) trial 18. Methods ABCSG-18 (NCT00556374) is a prospective, randomized, double-blind, phase III study; postmenopausal patients with hormone receptor (HR) positive BC receiving a non-steroidal aromatase inhibitor were randomly assigned to denosumab or placebo. In this post-hoc analysis, we investigated the potential effects of concomitant statin therapy on recurrence risk of BC, fracture risk and bone mineral density (BMD) using time-dependent Cox proportional hazards models. Sensitivity analyses accounting for immortal time and confounding bias were performed. Results In the analysis of the study population (n=3,420), statin therapy (n=824) was associated with worse disease-free survival (DFS) (HR 1.35, 95%; CI 1.04-1.75; p=0.023). Sensitivity analysis relativized these results (HR 1.22, 95% CI 0.94 - 1.59; p=0.14). While there was no significant effect of lipophilic statins (n=710) on recurrence risk (HR 1.30, 95% CI 0.99 - 1.72; p=0.062), patients on hydrophilic statins (n=87) had worse DFS compared with patients not receiving any statins (HR 2.00, 95% CI 1.09-3.66; p=0.026). This finding was mainly driven by the effect of hydrophilic statins on DFS in the denosumab arm (HR 2.63, 95% CI 1.21 - 5.68; p=0.014). No association between statin use and fracture risk or osteoporosis was observed. Conclusion In this population of early-stage breast cancer patients from a prospective randomized study, an association of hydrophilic statins with increased recurrence risk was observed. According to this retrospective analysis hydrophilic statins may increase recurrence risk especially in patients treated with denosumab. Still, our data need to be interpreted with caution due to their retrospective nature and the low number of patients receiving hydrophilic statins. Therefore, no final conclusion is possible. This hypothesis generating result warrants further exploration.

Citation Format: Christoph Minichsdorfer, Thorsten Fuereder, Michael Leutner, Christian F. Singer, Stephanie Kacerovsky-Strobl, Daniel Egle, Richard Greil, Marija Balic, Florian Fitzal, Georg Pfeiler, Sophie Frantal, Rupert A. Bartsch, Michael Gnant. Effect of concomitant statin treatment in postmenopausal patients with hormone-receptor positive early-stage breast cancer receiving adjuvant denosumab or placebo: A post-hoc analysis of ABCSG-18 [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-15-01.

Abstract GS2-04: Aromatase inhibitors versus tamoxifen in pre-menopausal women with estrogen receptor positive early stage breast cancer treated with ovarian suppression: A patient level meta-analysis of 7,030 women in four randomised trials

Background: For women with early stage hormone receptor positive breast cancer, adjuvant treatment with tamoxifen reduces their 15-year risk of death from breast cancer by about one third. Aromatase inhibitors (AIs) are even more effective than tamoxifen in post-menopausal women but, used alone, are ineffective in pre-menopausal women due to compensatory ovarian oestrogen production. Several trials have assessed whether, if administered with ovarian suppression, AIs may also be more effective than tamoxifen at preventing breast cancer recurrence in premenopausal women but trial results have been inconsistent. Methods: Individual patient data were available from four randomised controlled trials, including 7,030 pre-menopausal women with estrogen receptor positive (ER+) breast cancer. All women received ovarian suppression or ablation and were randomised to receive either an AI or tamoxifen for 3 years (in ABCSG XII) or 5 years in other trials (SOFT, TEXT and HOBOE). Primary outcomes for the meta-analysis were time to invasive breast cancer recurrence (distant, loco-regional, or new contralateral breast primary) and breast cancer mortality. Log-rank analyses were used to estimate first-event rate ratios (RR) and their confidence intervals (CIs). Results: Overall, the annual rate of recurrence averaged 21% lower (RR 0.79, 95% 0.69-0.90, p=0.0005) for women allocated AI compared to tamoxifen. The main benefit from AI was seen in years 0-4 (RR 0.68, 99% CI 0.58-0.80), during the period when treatments differed, with no further benefit, or loss of benefit, in years 5-9 (RR 0.98, 99% 0.73-1.32), and as yet limited follow up data available beyond year 10. The 5-year absolute risk of breast cancer recurrence was 3.2% lower in the AI group than the tamoxifen group (6.9% vs 10.1%, p=0.0005). Although distant recurrence was reduced with AI (RR 0.83, 95% CI 0.71-0.97, p=0.02), there was no difference in breast cancer mortality although longer follow up is needed to assess effects on mortality reliably. The proportional reduction in recurrence during the period when treatments differed did not vary by age, BMI, or by tumour size, tumour grade, histological subtype, or presence and absence of chemotherapy. In contrast to the findings of the meta-analysis of AI vs tamoxifen in postmenopausal women, AI appeared ineffective in N4+ disease (RR=0.49 in N0, RR=0.56 in N1-3, RR=1.03 in N4+; p for trend =0.0009). The only other apparent heterogeneity was between the four trial results (p=0.03), and between HER2-negative and positive disease (p=0.05), which may be chance findings given the borderline statistical significance. There were more bone fractures in women receiving AI (5.0% AI vs 3.8% Tam, p=0.02). Among these younger women, few non-breast cancer deaths occurred: 0.9% AI vs 0.7% Tam (RR 1.30, 95% CI 0.75-2.25), and the incidence of endometrial cancer was low (0.2% AI vs 0.3% tamoxifen, p=0.14). Conclusion: Using an AI rather than tamoxifen, in premenopausal women receiving ovarian suppression, reduces the risk of breast cancer recurrence by about 20%. If the surprising lack of benefit in N4+ disease is a chance finding, then the absolute benefits will be larger for women at a higher absolute risk of recurrence.

Citation Format: Rosie Bradley, Jeremy Braybrooke, Richard Gray, Robert K Hills, Zulian Lui, Hongchao Pan, Richard Peto, Jonas Bergh, Sandra M Swain, Prudence Francis, Michael Gnant, Francesco Perrone, Meredith M Regan. Aromatase inhibitors versus tamoxifen in pre-menopausal women with estrogen receptor positive early stage breast cancer treated with ovarian suppression: A patient level meta-analysis of 7,030 women in four randomised trials [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr GS2-04.