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.

Circulating tumor DNA association with residual cancer burden after neoadjuvant chemotherapy in triple-negative breast cancer in TBCRC 030

BACKGROUND

We aimed to examine circulating tumor DNA (ctDNA) and its association with residual cancer burden (RCB) using an ultrasensitive assay in patients with triple-negative breast cancer (TNBC) receiving neoadjuvant chemotherapy.

PATIENTS AND METHODS

We identified responders (RCB 0/1) and matched non-responders (RCB 2/3) from the phase II TBCRC 030 prospective study of neoadjuvant paclitaxel versus cisplatin in TNBC. We collected plasma samples at baseline, 3 weeks and 12 weeks (end of therapy). We created personalized ctDNA assays utilizing MAESTRO mutation enrichment sequencing. We explored associations between ctDNA and RCB status and disease recurrence.

RESULTS

Of 139 patients, 68 had complete samples and no additional neoadjuvant chemotherapy. Twenty-two were responders and 19 of those had sufficient tissue for whole-genome sequencing. We identified an additional 19 non-responders for a matched case-control analysis of 38 patients using a MAESTRO ctDNA assay tracking 319-1000 variants (median 1000 variants) to 114 plasma samples from 3 timepoints. Overall, ctDNA positivity was 100% at baseline, 79% at week 3 and 55% at week 12. Median tumor fraction (TFx) was 3.7 × 10-4 (range 7.9 × 10-7-4.9 × 10-1). TFx decreased 285-fold from baseline to week 3 in responders and 24-fold in non-responders. Week 12 ctDNA clearance correlated with RCB: clearance was observed in 10 of 11 patients with RCB 0, 3 of 8 with RCB 1, 4 of 15 with RCB 2 and 0 of 4 with RCB 3. Among six patients with known recurrence, five had persistent ctDNA at week 12.

CONCLUSIONS

Neoadjuvant chemotherapy for TNBC reduced ctDNA TFx by 285-fold in responders and 24-fold in non-responders. In 58% (22/38) of patients, ctDNA TFx dropped below the detection level of a commercially available test, emphasizing the need for sensitive tests. Additional studies will determine whether ctDNA-guided approaches can improve outcomes.

ESMO expert consensus statements (ECS) on the definition, diagnosis, and management of HER2-low breast cancer

Human epidermal growth factor receptor 2 (HER2)-low breast cancer has recently emerged as a targetable subset of breast tumors, based on the evidence from clinical trials of novel anti-HER2 antibody-drug conjugates. This evolution has raised several biological and clinical questions, warranting the establishment of consensus to optimally treat patients with HER2-low breast tumors. Between 2022 and 2023, the European Society for Medical Oncology (ESMO) held a virtual consensus-building process focused on HER2-low breast cancer. The consensus included a multidisciplinary panel of 32 leading experts in the management of breast cancer from nine different countries. The aim of the consensus was to develop statements on topics that are not covered in detail in the current ESMO Clinical Practice Guideline. The main topics identified for discussion were (i) biology of HER2-low breast cancer; (ii) pathologic diagnosis of HER2-low breast cancer; (iii) clinical management of HER2-low metastatic breast cancer; and (iv) clinical trial design for HER2-low breast cancer. The expert panel was divided into four working groups to address questions relating to one of the four topics outlined above. A review of the relevant scientific literature was conducted in advance. Consensus statements were developed by the working groups and then presented to the entire panel for further discussion and amendment before voting. This article presents the developed statements, including findings from the expert panel discussions, expert opinion, and a summary of evidence supporting each statement.

Risk-adapted modulation through de-intensification of cancer treatments: an ESMO classification

BACKGROUND

The landscape of clinical trials testing risk-adapted modulations of cancer treatments is complex. Multiple trial designs, endpoints, and thresholds for non-inferiority have been used; however, no consensus or convention has ever been agreed to categorise biomarkers useful to inform the treatment intensity modulation of cancer treatments.

METHODS

An expert subgroup under the European Society for Medical Oncology (ESMO) Precision Medicine Working Group shaped an international collaborative project to develop a classification system for biomarkers used in the cancer treatment de-intensification, based on a tiered approach. A group of disease-oriented clinical, translational, methodology and public health experts, and patients' representatives provided an analysis of the status quo, and scanned the horizon of ongoing clinical trials. The classification was developed through multiple rounds of expert revisions and inputs.

RESULTS

The working group agreed on a univocal definition of treatment de-intensification. Evidence of reduction in the dose-density, intensity, or cumulative dose, including intermittent schedules or shorter treatment duration or deletion of segment(s) of the standard regimens, compound(s), or treatment modality must be demonstrated, to define a treatment de-intensification. De-intensified regimens must also portend a positive impact on toxicity, quality of life, health system burden, or financial toxicity. ESMO classification categorises the biomarkers for treatment modulation in three tiers, based on the level of evidence. Tier A includes biomarkers validated in prospective, randomised, non-inferiority clinical trials. The working group agreed that in non-inferiority clinical trials, boundaries are highly dependent upon the disease scenario and endpoint being studied and that the absolute differences in the outcomes are the most relevant measures, rather than relative differences. Biomarkers tested in single-arm studies with a threshold of non-inferiority are classified as Tier B. Tier C is when the validation occurs in prospective-retrospective quality cohort investigations.

CONCLUSIONS

ESMO classification for the risk-guided intensity modulation of cancer treatments provides a set of evidence-based criteria to categorise biomarkers deemed to inform de-intensification of cancer treatments, in risk-defined patients. The classification aims at harmonising definitions on this matter, therefore offering a common language for all the relevant stakeholders, including clinicians, patients, decision-makers, and for clinical trials.

Continuous versus intermittent extended adjuvant letrozole for breast cancer: final results of randomized phase III SOLE (Study of Letrozole Extension) and SOLE Estrogen Substudy

BACKGROUND

Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment.

PATIENTS AND METHODS

SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5).

RESULTS

Intention-to-treat population included 4851 women in SOLE (n = 2425 in the intermittent and n = 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n = 78 in the intermittent and n = 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment.

CONCLUSIONS

Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption.

Neoadjuvant treatment strategies for HER2-positive breast cancer: cost-effectiveness and quality of life outcomes

PURPOSE

Achieving a pathologic complete response (pCR) with neoadjuvant therapy for HER2-positive breast cancer is associated with less recurrence and improved clinical outcomes compared to having residual cancer at surgery. However, recent data have demonstrated favorable outcomes for patients with residual HER2-positive cancer who received adjuvant trastuzumab emtansine (TDM-1). Therefore, we sought to determine the optimal chemotherapy/anti-HER2 treatment strategy.

METHODS

We created a decision-analytic model for patients with stage II-III HER2-positive cancer that incorporated utilities based on toxicity and recurrence. We separately modeled hormone receptor-negative (HR-) and positive (HR+) disease and calculated quality-adjusted life years (QALYs) and costs through 5 years. Simulated patients received one of the following neoadjuvant treatments: three 'intensive' regimens (TCHP: docetaxel, carboplatin, trastuzumab, pertuzumab; THP + AC: taxol, trastuzumab, pertuzumab then doxorubicin and cyclophosphamide; THP: taxol, trastuzumab, pertuzumab) and two 'de-escalated' regimens (TH: taxol, trastuzumab; TDM-1) followed by adjuvant treatment based on pathologic response.

RESULTS

Among 'intensive' neoadjuvant strategies, treatment with THP was more effective and less costly than TCHP or THP + AC. When 'de-escalated' strategies were included, TH became the most cost-effective. For HR-negative cancer, TH had 0.003 fewer quality-adjusted life years (QALYs) than THP but was less costly by $55,831, resulting in an incremental cost-effectiveness ratio of over $18M/QALY for THP, well above any threshold. For HR-positive cancer, neoadjuvant TH dominated the THP strategy.

CONCLUSION

An adaptive-treatment strategy beginning with neoadjuvant THP or TH followed by tailoring post-operative therapy reduces treatment costs, and spares toxicity compared to more intensive chemotherapy regimens for women with HER2-positive breast cancer.

Estimating the benefits of therapy for early-stage breast cancer: the St. Gallen International Consensus Guidelines for the primary therapy of early breast cancer 2019

BACKGROUND

The 16th St. Gallen International Breast Cancer Conference 2019 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer.

DESIGN

Treatments were assessed in light of their intensity, duration and side-effects, estimating the magnitude of clinical benefit according to stage and biology of the disease. The Panel acknowledged that for many patients, the impact of adjuvant therapy or the adherence to specific guidelines may have modest impact on the risk of breast cancer recurrence or overall survival. For that reason, the Panel explicitly encouraged clinicians and patients to routinely discuss the magnitude of benefit for interventions as part of the development of the treatment plan.

RESULTS

The guidelines focus on common ductal and lobular breast cancer histologies arising in generally healthy women. Special breast cancer histologies may need different considerations, as do individual patients with other substantial health considerations. The panelists' opinions reflect different interpretation of available data and expert opinion where is lack of evidence and sociocultural factors in their environment such as availability of and access to medical service, economic resources and reimbursement issues. Panelists encourage patient participation in well-designed clinical studies whenever available.

CONCLUSIONS

With these caveats in mind, the St. Gallen Consensus Conference seeks to provide guidance to clinicians on appropriate treatments for early-stage breast cancer and guidance for weighing the realistic tradeoffs between treatment and toxicity so that patients and clinical teams can make well-informed decisions on the basis of an honest reckoning of the magnitude of clinical benefit.

A phase II feasibility study of palbociclib in combination with adjuvant endocrine therapy for hormone receptor-positive invasive breast carcinoma

BACKGROUND

The CDK4/6 inhibitor palbociclib prolongs progression-free survival in hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer when combined with endocrine therapy. This phase II trial was designed to determine the feasibility of adjuvant palbociclib and endocrine therapy for early breast cancer.

PATIENTS AND METHODS

Eligible patients with HR+/HER2- stage II-III breast cancer received 2 years of palbociclib at 125 mg daily, 3 weeks on/1 week off, with endocrine therapy. The primary end point was discontinuation from palbociclib due to toxicity, non-adherence, or events related to tolerability. A discontinuation rate of 48% or higher would indicate the treatment duration of 2 years was not feasible, and was evaluated under a binomial test using a one-sided α = 0.025.

RESULTS

Overall, 162 patients initiated palbociclib; over half had stage III disease (52%) and most received prior chemotherapy (80%). A total of 102 patients (63%) completed 2 years of palbociclib; 50 patients discontinued early for protocol-related reasons (31%, 95% CI 24% to 39%, P = 0.001), and 10 discontinued due to protocol-unrelated reasons. The cumulative incidence of protocol-related discontinuation was 21% (95% CI 14% to 27%) at 12 months from start of treatment. Rates of palbociclib-related toxicity were congruent with the metastatic experience, and there were no cases of febrile neutropenia. Ninety-one patients (56%) required at least one dose reduction.

CONCLUSION

Adjuvant palbociclib is feasible in early breast cancer, with a high proportion of patients able to complete 2 years of therapy. The safety profile in the adjuvant setting mirrors that observed in metastatic disease, with approximately half of the patients requiring dose-modification. As extended duration adjuvant palbociclib appears feasible and tolerable for most patients, randomized phase III trials are evaluating clinical benefit in this population.

CLINICALTRIALS.GOV REGISTRATION

NCT02040857.

Abstract GS4-02: Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor positive (HR+) early breast cancer (BC): Update of the combined TEXT and SOFT trials

Background: The combined results of TEXT and SOFT, after 5.7 years median follow-up, found adjuvant E+OFS significantly improved disease-free survival (DFS) vs T+OFS in premenopausal women with HR+ BC (Pagani et al, NEJM 2014). Follow-up was immature for overall survival (OS). We report a planned update with visit cut-off of 31Dec16 after 9 years median follow-up.

Methods: TEXT and SOFT enrolled premenopausal women with HR+ early BC from Nov 2003 to Apr 2011 (2660 TEXT, 3047 SOFT in the intention-to-treat populations). TEXT randomized women within 12wk of surgery to 5 yrs E+OFS vs T+OFS; chemotherapy (CT) was optional and concurrent with OFS. SOFT randomized women to 5 yrs E+OFS vs T+OFS vs T alone, within 12wk of surgery if no CT planned, or within 8mo of completing (neo)adjuvant CT after premenopausal status was (re-)established. OFS was by choice of 5yr GnRH agonist triptorelin, oophorectomy or ovarian irradiation. Both trials were stratified by CT use. The primary endpoint was DFS: randomization until invasive local, regional, distant recurrence or contralateral breast; invasive second malignancy; death. Secondary endpoints included invasive breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and OS. Stratified Cox models estimated hazard ratios; Kaplan-Meier method estimated 8yr endpoint rates. NCT00066703/NCT00066690.

Results: DFS for patients assigned E+OFS (n=2346) continued to be significantly improved over T+OFS (n=2344): 8yr DFS was 86.8% vs. 82.8%. The 8yr BCFI was improved by 4.1% (89.3% vs 85.2%) and 8yr DRFI by 2.1% (91.8% vs 89.7%). There was no difference in OS in patients assigned E+OFS vs T+OFS: 93.4% vs 93.3% OS at 8yrs. For 1996 women without CT there have been 45 deaths, with 98% OS at 8yrs with both treatments.

EndpointN. EventsHazard Ratio (95% CI) E+OFS vs T+OFSDFS7200.77 (0.67-0.90); P<0.001BCFI6000.74 (0.63-0.87)DRFI4330.80 (0.65-0.96)OS3200.98 (0.79-1.22)

Overall toxicity was not significantly worse with E+OFS than with T+OFS (32% vs 31% grade 3-4 targeted AEs). Hot flashes, musculoskeletal symptoms and hypertension were the most frequent targeted grade 3-4 AEs. Overall, 15% of patients stopped all protocol-assigned treatment early. Patients assigned E+OFS had increased risk of assigned oral endocrine therapy cessation (25% vs 19% for patients assigned T+OFS by 4yrs) but not of triptorelin cessation (18% vs 19% by 4yrs, respectively).

Conclusions: After 9 yrs median follow-up, adjuvant E+OFS, as compared with T+OFS, shows a sustained reduction of the risk of recurrence but did not improve overall survival. As in postmenopausal women, oncologists need to consider potential absolute benefits and properly select patients at sufficient risk for recurrence for whom E+OFS seems indicated. Follow-up continues, which will further clarify the effect of E+OFS for safety, late recurrence and overall survival.

Citation Format: Pagani O, Regan MM, Fleming GF, Walley BA, Colleoni M, Láng I, Gomez HL, Tondini C, Burstein HJ, Goetz MP, Ciruelos EM, Stearns V, Debled M, Martino S, Geyer Jr CE, Pinotti G, Coates AS, Goldhirsch A, Gelber RD, Francis PA. Randomized comparison of adjuvant aromatase inhibitor exemestane (E) plus ovarian function suppression (OFS) vs tamoxifen (T) plus OFS in premenopausal women with hormone receptor positive (HR+) early breast cancer (BC): Update of the combined TEXT and SOFT trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS4-02.

Abstract OT3-05-08: PALLAS: PALbociclib CoLlaborative Adjuvant Study: A randomized phase 3 trial of palbociclib with standard adjuvant endocrine therapy versus standard adjuvant endocrine therapy alone for HR+/HER2- early breast cancer

Background:

Cell cycle inhibition is a proven target for novel cancer therapeutics. Palbociclib (P) is an orally active inhibitor of CDK4/6, and arrests the cell cycle at the G1-S transition. P in combination with endocrine therapy (ET) has demonstrated efficacy in phase II and III randomized trials for patients with newly diagnosed and recurrent hormone receptor positive/HER2 negative (HR+/HER2-) metastatic breast cancer (MBC), and is approved in these settings. Given confirmed benefits of P and ET for MBC, the PALLAS study was designed to determine if the addition of P to adjuvant ET improves outcomes over ET alone in HR+/HER2- early breast cancer.

Trial Design:

PALLAS is an international open-label phase III trial randomizing (1:1) patients (pts) to 2 years of P (125 mg daily, 21 days on 7 days off in a 28-day cycle) combined with at least 5 years of provider choice ET (AI, tamoxifen, +/- LHRH agonist), versus ET alone. The primary objective of the study is to compare invasive disease-free survival (iDFS) for the combination of P and ET, versus ET alone. Secondary objectives include comparison of iDFS excluding cancer of non-breast origin, DRFS, LRRFS, OS, as well as safety. The principal objective of the translational investigations is to determine the predictive or prognostic utility of defined genomic subgroups with respect to iDFS and OS. Additional objectives include evaluation of cfDNA and tissue biomarkers predictive of benefit or resistance, pharmacogenomics, adherence, and patient-reported QOL. Eligible pts are pre- or post-menopausal women or men with stage II-III, HR+/HER2- breast cancer. Patients may have already initiated ET, but must be randomized within 12 months of diagnosis and 6 months of initiation of adjuvant ET. Trial sample size is 4600 pts and stage IIA pts will be capped at a total accrual of 1000 pts. Interim analyses for safety, futility/efficacy and sample size re-estimation are planned. PALLAS opened in 9/2015 and accrual is ongoing. Contact information: emayer@partners.org

Key words: palbociclib, CDK4/6 inhibition, HR+/HER2- early breast cancer, adjuvant endocrine therapy.

Citation Format: Mayer E, DeMichele A, Gnant M, Barry W, Pfeiler G, Metzger O, Burstein H, Miller K, Rastogi P, Loibl S, Goulioti T, Zardavas D, Fesl C, Koehler M, Huang-Bartlett C, Huang X, Piccart M, Winer E, Wolff A. PALLAS: PALbociclib CoLlaborative Adjuvant Study: A randomized phase 3 trial of palbociclib with standard adjuvant endocrine therapy versus standard adjuvant endocrine therapy alone for HR+/HER2- early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT3-05-08.

Abstract P1-07-04: Physical activity, weight and outcomes in patients receiving first-line chemotherapy for metastatic breast cancer: Results from CALGB 40502 (Alliance)

Background: Obesity and inactivity are associated with an increased risk of cancer-related and overall mortality in women with early-stage breast cancer, but there are few data in advanced breast cancer.

Methods: C40502 was a Phase III trial of first-line chemotherapy for patients with metastatic breast cancer (MBC). Participants were randomized to weekly paclitaxel, nab-paclitaxel or ixabepilone. Height and weight at the time of study enrollment were abstracted from medical records. After study activation, the protocol was amended to collect physical activity (PA) data. Participants completed the Nurses' Health Study Exercise Questionnaire, indicating the frequency, type and duration of recreational PA in which they engaged at study enrollment. Metabolic equivalent (MET)-hours of weekly PA (MET-hrs/wk) were calculated using the Ainsworth Compendium. PA was dichotomized to 0-9 or 9+ MET-hrs/wk based on data in early stage breast cancer suggesting that women who engaged in > 9 MET-hrs of PA/wk had lower cancer-specific mortality. Association with clinical endpoints was evaluated using multivariate Cox proportional hazard models adjusting for treatment assignment, age, tumor hormone-receptor status, prior taxane use, disease-free interval and visceral metastases.

Results: 799 patients enrolled in C40502 between 2008 and 2011. Baseline body mass index (BMI) was available for 792 patients and PA data for 500 participants. Median follow up was 60 months. Median age was 56.7 years; 72% of patients had hormone receptor (HR)-positive cancers. Median BMI was 28.6 kg/m2 (IQR: 24.7-33.1 kg/m2). Patients engaged in a median of 3.3 MET-hrs/wk of PA (about 1 hour of moderate-intensity PA/wk) (IQR: 0.7-12.7 MET-hrs/wk). Neither BMI nor PA was significantly associated with progression-free (PFS) or overall survival (OS).

BMI and OutcomesBMI (kg/m2)N (%)PFS (months)Adj HRP valueOS (months)Adj HRP value18.5-24.9209 (26.4)10.0 (9.1-11.2)ref0.4826.1 (23.3-33.2)ref0.5425-29.9248 (31.3)9.0 (7.6-10.3)1.00 (0.83-1.22) 22.0 (20.0-25.4)1.05 (0.85-1.30) ≥30335 (42.3)8.7 (7.7-9.7)0.97 (0.81-1.17) 25.5 (23.1-29.5)0.95 (0.78-1.16) 

PA and OutcomesPA (MET-hrs/wk)N (%)PFS (months)Adj HRP valueOS (months)Adj HRP value0-9344 (68.8)7.9 (7.4-9.2)ref0.1323.6 (20.1-26.8)ref0.21>9156 (31.2)9.8 (8.9-12.0)0.86 (0.71-1.05) 27.4 (22.3-35.6)0.87 (0.70-1.08) 

There was a trend toward longer PFS and OS in patients who reported PA > 9 MET-hrs/wk vs 0-9 MET-hrs/wk, especially in individuals with HR+ cancers (median PFS 11.7 vs 9.2 months [adj HR = 0.84 (0.66-1.05)] and OS 34.0 vs 26.5 months [adj HR = 0.83 (0.66-1.05)] with PA >9 vs 0- 9 MET-hrs/wk).

Conclusions: In some of the first data looking at the relationship between lifestyle factors and outcomes in MBC, there was no relationship between BMI and PFS or OS in patients receiving first-line chemotherapy for advanced disease. A trend toward improved PFS and OS was seen in multivariate analysis in patients who reported higher levels of PA, but results were not statistically significant and could have been influenced by other patient factors. More information is needed regarding the relationship between PA and cancer outcomes, especially in patients with HR+ cancers.

Citation Format: Ligibel JA, Huebner LJ, Rugo HS, Burstein H, Toppmeyer DL, Anders CK, Ma C, Hudis CA, Winer EP, Barry WT. Physical activity, weight and outcomes in patients receiving first-line chemotherapy for metastatic breast cancer: Results from CALGB 40502 (Alliance) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-04.

Abstract P3-11-01: Treatment patterns for young women with HR+/HER2- metastatic breast cancer in the United States in the era of CDK 4/6 inhibitors

Background: NCCN guidelines recommend that premenopausal women with HR+/HER2- metastatic breast cancer (MBC) be rendered postmenopausal and then treated accordingly. After its approval in February 2015, the CDK4/6 inhibitor palbociclib (P), in combination with endocrine therapy (ET), has become a standard of care in the first-line or pretreated settings for women with HR+/HER2- MBC. Specialty pharmacy prescription data indicate that 12% of all women with HR+/HER2- MBC treated with P in the United States are younger than 50 years of age. We assessed the real world treatment patterns and outcomes before and after approval of P in women with HR+/HER2- MBC. We further sought to assess the impact of the NCCN guidelines for premenopausal women on treatment patterns and outcomes.

Methods: This retrospective cohort study utilized electronic health record (EHR) data from Flatiron Health (Fl) from 1/2012 through 4/2017 to evaluate patient characteristics and first-line ET treatment patterns among women with HR+/HER2- MBC prior to and after P approval. Menopausal status was defined by age (< 50 vs >50 yrs). Additional datasets of > 13,000 pts with MBC in the Truven Health MarketScan and Optum Clinformatics claims and Humedica EHR databases will be included to represent a more comprehensive dataset and evaluate clinical outcomes.

Results and Discussion: Initial results include 4,537 pts in the FI database who initiated a first-line ET regimen. Overall, 30% of pts < 50 yrs used P compared to 29% of women age >50. Treatment patterns for initial endocrine therapy are shown in the table.

Initial Endocrine Therapy Women <_50 yrs N (%) women > 50 yrs N(%) cohort01.2012-01.201502.2015-04.2017Absolute Change01.2012-01.201502.2015-04.2017Absolute ChangeN (%)296 (%0273 (100%) 2062 (100%)1906 (100%) ET monotx +/- LHRH296 (100%)192 (70%)-30%2062 (100%)1345 (71%)-29%TAM108 (36%)75 (27%)-9%161 (8%)78 (4%)-4%AI139 (47%)80 (29%)-18%1326 (64%)866 (45%)-19%FUL49 (17%)37 (14%)-3%575 (28%)401 (21%)-7%ET + P +/- LHRHNA81 (30%)+30%NA561 (29%)+29%% of concurrent LHRH77 (26%)92 (34%)+8%20 (1%)28 (1%)0%

Decreased use of tamoxifen as 1st line ET was observed in pts <_50 yrs over the observed time. 47% of young pts initiated endocrine based treatment with AI monotherapy in the pre-P era, consistent with the NCCN guidelines. About 26% (pre-P) and 34% (post-P) of pts ≤50 yrs initiated first ET with ovarian suppression in the analyzed treatment eras. The concurrent use of LHRH increased 8%.

Conclusions: The treatment paradigm for women with HR+/HER2- MBC has evolved over the last >5 years. Consistent with NCCN guidelines, more young pts are receiving ovarian suppression as part of initial therapy, and pts regardless of age are receiving treatment with P. There has been a related decrease in use of tamoxifen for younger pts and overall. These data illustrate rapid incorporation of palbociclib into standard care for US pts with HR+/HER2- MBC. Further treatment patterns and therapy outcome data for these groups reflecting real world use ET regimens of over 17,000 pts in the combined cohort, will be reported.

Citation Format: Burstein HJ, Mayer EL, DeMichele A, Harnett J, Mardekian J, McRoy L, Huang Bartlett C, Koehler M, Fahed Rimawi M. Treatment patterns for young women with HR+/HER2- metastatic breast cancer in the United States in the era of CDK 4/6 inhibitors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-01.

Abstract GS4-03: Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial

Background: The primary results of SOFT at 5.6 years median follow-up found adding OFS to T did not provide a significant benefit in the overall study population of premenopausal women with HR+ BC (Francis et al, NEJM 2015). For those women at sufficient risk for recurrence to warrant adjuvant chemotherapy (CT) and who remained premenopausal, the addition of OFS improved disease outcomes. Follow-up was immature for overall survival (OS). We report a planned update with visit cut-off of 31Dec16 after 8 yrs median follow-up.

Methods: SOFT randomized premenopausal women with HR+ BC from Nov 2003 to Jan 2011 to 5 yrs of T vs T+OFS vs Exemestane(E)+OFS. OFS was by choice of GnRH agonist triptorelin, oophorectomy or ovarian irradiation. SOFT was stratified by the use of prior CT; 47% received no CT and 53% remained premenopausal after prior CT, determined by premenopausal estradiol level within 8 months of CT completion. The primary endpoint was invasive disease-free survival (DFS; randomization until invasive local, regional, distant recurrence or contralateral breast; invasive second malignancy; death). Secondary endpoints included invasive breast cancer-free interval (BCFI), distant recurrence-free interval (DRFI) and OS. NCT00066690.

Results: DFS for patients assigned T+OFS (n=1015) was significantly improved over T (n=1018; HR=0.76 [95%CI 0.62-0.93]) and 8yr DFS was 83.2% vs 78.9%, respectively; BCFI and DRFI results were supportive (see Table). Hazard ratios for these 3 endpoints showed no heterogeneity by use of prior CT. For patients with prior CT, 8yr DFS was 76.7% with T+OFS vs 71.4% with T (Δ=5.3%); in those without CT, 8yr DFS was 90.6% vs 87.4% (Δ=3.2%). E+OFS (n=1014) improved outcomes relative to T (Table); 8yr DFS for E+OFS was 85.9% (80.4% with use of prior CT and 92.5% for those without CT). OS was improved with T+OFS vs T (8yr OS 93.3% vs 91.5%). 8yr OS was 92.1% with E+OFS. 201/225 deaths occurred in women with prior CT. For women without CT there have been 10, 5 and 9 deaths in the T+OFS, T and E+OFS groups (total n=1419), respectively, only half of these deaths after breast cancer event.

N. EventsHazard Ratio (95% CI)Endpoint(3 arms)T+OFS vs TE+OFS vs TDFS5180.76 (0.62-0.93) P=0.0090.65 (0.53-0.81)BCFI4370.76 (0.61-0.95)0.64 (0.51-0.81)DRFI3060.86 (0.66-1.13)0.73 (0.55-0.96)OS2250.67 (0.48-0.92)0.85 (0.62-1.15)

Overall toxicity was worse with T+ OFS than with T, including 32% vs 25% grade 3+ targeted AEs. Early cessation of tamoxifen occurred for 19% assigned T+OFS and 22% of women assigned T; the cumulative incidence of early cessation of triptorelin on the T+OFS arm was 23% by 4yrs. Early cessation of exemestane occurred for 28% and of triptorelin for 21% by 4yrs on the E+OFS arm.

Conclusions: With additional follow-up to a median of 8yrs, SOFT further supports the value of OFS for some premenopausal women. Follow-up continues, which will further clarify the safety and the benefit of OFS for late recurrence and overall survival. Oncologists appear to be able to select a low risk group (no chemotherapy) for whom treatment escalation is unlikely to improve survival.

Citation Format: Fleming G, Francis PA, Láng I, Ciruelos EM, Bellet M, Bonnefoi HR, Climent MA, Pavesi L, Burstein HJ, Martino S, Davidson NE, Geyer Jr CE, Walley BA, Coleman RE, Kerbrat P, Buchholz S, Ingle JN, Rabaglio-Poretti M, Colleoni M, Regan MM. Randomized comparison of adjuvant tamoxifen (T) plus ovarian function suppression (OFS) versus tamoxifen in premenopausal women with hormone receptor-positive (HR+) early breast cancer (BC): Update of the SOFT trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS4-03.

Abstract PD5-06: Adjuvant palbociclib plus endocrine therapy for hormone receptor positive/HER2 negative breast cancer: A phase II feasibility study

Background:

The CDK4/6 inhibitor palbociclib (P) combined with endocrine therapy (ET) prolongs progression-free survival in previously untreated and treated hormone receptor positive/HER2 negative (HR+/HER2-) metastatic breast cancer (MBC). The most common toxicity with P is neutropenia, typically non-cumulative and uncomplicated. Given observed benefits of P in metastatic BC, this single arm phase II trial was designed to determine the feasibility and toxicity of combination adjuvant P and ET for HR+/HER2- early BC (EBC).

Methods:

Eligible patients (pts) had HR+/HER2- stage II (not T2N0)-III EBC, with prior completion of 3-24 mo of ET (either AI or tamoxifen) without significant adverse events (AE). Pts received P at 125 mg daily, 3 wk on/1 wk off in a 28d cycle, plus continuous ET, for planned duration 2 yrs. Pts were removed from study for toxicity, non-adherence, or other events related to tolerability; pts who recurred or completed 2 yrs of therapy were censored for the primary endpoint. The primary objective was to evaluate the treatment discontinuation rate at 2 yrs; a rate of >50%, would indicated a non-feasible treatment duration (null hypothesis). Discontinuation rates at 2 yrs are estimated by Kaplan Meier with 95% confidence bands. A sample size of 160 pts provided 92% power to reject the null hypothesis using a one-sided alpha = 0.025 if the true rate of discontinuation is <33.3%, and accounting for a censoring rate of up to 20% over the 2 yrs. Secondary endpoints include toxicity, adherence, QOL, and pharmacogenomics.

Results:

Between 3/2014 and 11/2015, 162 pts initiated P; the majority had stage III EBC (52%) and received prior chemotherapy (63%). As of 05/2017, 120 (74%) have completed at least 1 yr of P + ET, and 50 (31%) have completed 2 yrs of P + ET. Early discontinuation of protocol treatment was reported for 59 pts (36%), including 49 events (30%) related to protocol-mandated (9%) and non-mandated (21%) tolerability. The cumulative rate of all discontinuations was 15.1% at 6 mos, 20.9% at 12 mos and 27.8% at 18 mos. Half of all non-mandated discontinuations occurred within the first 6 mos of initiation of therapy, and the rate decreased with greater provider and pt education. Median duration of pts still on treatment is 20 mos (inter-quartile range: 18 to 21 mos). The rate of grade 3/4 neutropenia was 77%, with 0 cases of febrile neutropenia. Other common all-grade P-related AE > 20% included fatigue 65%, alopecia 25%, mucositis 24%, and anemia 24%. 32% of pts required one dose reduction, 16% required two. There have been 2 BC recurrence events and 1 chemotherapy-related AML. Updated data for the primary analysis of feasibility and tolerability, as well as pharmacogenomics, QOL, and adherence, will be presented.

Conclusions:

In this single arm phase II trial, the majority of pts have completed at least 1 year of adjuvant P + ET therapy, with no new toxicity signals. Non-protocol discontinuations have decreased with education. Updated results for the primary analysis will be presented. As in the MBC setting, extended duration palbociclib appears feasible and tolerable for most pts. The efficacy of 2 years of P and ET will be addressed by the phase III PALLAS trial (NCT NCT02513394).

Citation Format: Mayer EL, DeMichele AM, Guo H, Miller KD, Rugo HS, Schneider B, Waks AG, Come SE, Mulvey T, Huang Bartlett C, Koehler M, Barry W, Winer EP, Burstein HJ. Adjuvant palbociclib plus endocrine therapy for hormone receptor positive/HER2 negative breast cancer: A phase II feasibility study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD5-06.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Abstract P2-09-09: The effects of treatment-induced symptoms, depression and age on sexuality in premenopausal women with early breast cancer receiving adjuvant endocrine therapy

Background: In premenopausal women with breast cancer any treatment that causes abrupt, premature ovarian failure increases the risk of sexual problems. Randomized-controlled trials in this population reported a worsening in sexual functioning over time irrespective of adjuvant endocrine treatment. We investigated key symptoms related to endocrine therapy, depression and age as predictors of sexual problems in premenopausal women with early breast cancer treated in the IBCSG TEXT/SOFT trials over the first two years of endocrine therapy.

Methods: A subset of patients (pts) enrolled by centers with English as primary language to TEXT (1027 of 2672 pts) and SOFT (1260 of 3066 pts) completed a questionnaire consisting of global and symptom-specific quality of life indicators, the CES-Depression (CES-D) and the MOS- Sexual Problems (MOS-SP) measures at baseline, 6, 12 and 24 months. The analysis considered 5 cohorts of pts according to chemotherapy use (yes/no), trial (SOFT/TEXT) and endocrine treatment assignment (tamoxifen alone [T], T or exemestane [E] with ovarian function suppression [OFS]). Mixed modeling was used to test the effect of the following on changes in sexual problems (MOS-SP total score) over two years: changes in treatment-induced symptoms (hot flushes, vaginal dryness, sleep disturbances, bone/joint pain, troubled by weight gain, tiredness, nausea/vomiting) from baseline to 6 months; depression at 6 months; and age at randomization. The model included severity groups of symptoms, depression (all dichotomized by median) and age (< 40 vs ≥40 years), 5 cohorts, time points (6, 12, 24 months), baseline covariates, and interactions of symptoms, timepoints and cohorts.

Results: Overall across cohorts, pts with more severe worsening of vaginal dryness and sleep disturbances at 6 months reported a greater increase in sexual problems at all timepoints (p<.0001). The effect of vaginal dryness on sexual problems was most pronounced in the cohort of pts who received T+OFS or E+OFS without chemotherapy; the effect of sleep disturbances was most pronounced in the cohort with prior chemotherapy and T alone. All other symptoms had a smaller impact on differences in changes of sexual problems. Significant effects were only seen in the short-term and varied according to cohort. Severity of depression at six months did not predict sexual problems at the later timepoints in the overall population. In the cohort that received T+OFS or E+OFS without chemotherapy, pts who had more severe depression scores at 6 months reported significantly worse sexual problems at all timepoints (p<.05). No differences were found for younger vs. older pts with respect to sexual problems at any timepoint.

Conclusion: Among several key symptoms related to endocrine therapy, only vaginal dryness and sleep disturbances significantly predicted sexual problems during the first two years in pts who received adjuvant endocrine therapy with or without chemotherapy. Depression predicted sexual problems only in the cohort of pts who received combined endocrine treatment without chemotherapy. Early identification of vaginal dryness, sleep disturbances and depression is important for timely and tailored interventions.

Citation Format: Ribi K, Luo W, Burstein HJ, Naughton MJ, Chirgwin J, Ansari RH, Walley BA, Salim M, van der Westhuizen A, Abdi E, Francis PA, Budman DR, Kennecke H, Harvey VJ, Giobbie-Hurder A, Fleming GF, Pagani O, Regan MM, Bernhard J. The effects of treatment-induced symptoms, depression and age on sexuality in premenopausal women with early breast cancer receiving adjuvant endocrine therapy [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-09-09.

Experts' perspectives on the role of medical marijuana in oncology: A semistructured interview study

BACKGROUND

Expansion of medical marijuana (MM) laws in the United States may offer oncology new therapeutic options. However, the scientific evidence for MM remains in infancy. This study qualitatively explored professional opinion around the role of MM in cancer care.

METHODS

Semistructured interviews were administered to a sample of individuals with expertise at the interface of MM and oncology nationally. Key informant criteria included an oncologic clinical or research background and any of the following: publications, research, or lectures on cannabinoids or cancer symptoms; involvement in the development of MM dispensaries or legislation; and early adoption of state MM certification procedures. A gold standard, grounded, inductive approach was used to identify underlying themes.

RESULTS

Participants (N = 15) were predominantly male, in their sixth decade, working in academic settings. Themes ranged from strong beliefs in marijuana's medical utility to reservations about this notion, with calls for expansion of the scientific evidence base and more stringent MM production standards. All participants cited nausea as an appropriate indication, and 13 of 15 pain. Over one-third believed MM to have a more attractive risk profile than opioids and benzodiazepines.

CONCLUSIONS

Expert opinion was divided between convictions in marijuana's medicinal potential and guardedness in this assertion, with no participant refuting MM's utility outright. Emergent themes included that MM ameliorates cancer-related pain and nausea and is safer than certain conventional medications. Participants called for enhanced purity and production standards, and further research on MM's utility.

Breast conservation following neoadjuvant therapy for breast cancer in the modern era: Are we losing the opportunity?

The main rationale for neoadjuvant therapy for breast cancer is to provide effective systemic treatment while surgically down-staging the cancer. This down-staging was initially to convert inoperable patients to operable and later to increase rates of breast conservation in patients initially deemed mastectomy only candidates. Unexpectedly, in recent neoadjuvant trials lower rates of breast conservation have been observed than in past decades, despite remarkable advances in systemic therapies, which have increased pathologic complete response rates. These results point to factors aside from response and eligibility for breast conservation that may lead surgeons and/or patients to recommend and choose mastectomy. Here, we aim to examine the surgical benefits offered by the modern era neoadjuvant therapy and explore factors that have contributed to this decrease in breast conservation rates. If the main benefit of neoadjuvant therapy is to increase the opportunity for breast conservation, then our review suggests that to optimize less invasive surgical approaches, we will need to address both surgeon and patient-level variables and biases that may be limiting our ability to identify patients appropriate for less aggressive options. As an oncology community, we must be aware of the surgical overtreatment of breast cancer, especially in a time where systemic therapies have remarkably improved outcomes and responses.

Abstract ES09-1: Update on management of ER positive metastatic breast cancer

Patients with ER positive, metastatic breast cancer are candidate for endocrine and chemotherapy treatments in order to prolong survival, alleviate and forestall symptoms, and preserve quality of life. Classical management strategies such as the prompt initiation of ovarian suppression at the time of diagnosis of metastatic disease, the sequential use of treatment with endocrine agents and chemotherapeutic agents, the predilection of ER positive tumors for bone / soft tissue / mucosal and lymph nodes as initial sites of metastatic disease, and the lack of close correlation between clinical benefit and overt treatment response to endocrine agents remain valuable observations. Despite decades of clinical use, important new findings regarding endocrine therapy continue to emerge. Several examples of recent innovation include the following. 1. Dosing of fulvestrant. Because of limited bioavailability in its injectable formulation, higher doses of fulvestrant (500 mg) yield superior clinical outcomes than seen with the lower doses (250 mg) originally used for drug approval. 2. Combinations of aromatase inhibitors and fulvestrant. Historically, single-agent endocrine treatment has been the norm. Recent studies have examined AI therapy given with or without fulvestrant. In the FACT trial, no substantial benefit was observed. However, in the SWOG 0221 study, the combination led to improved overall survival, perhaps because this patient population had received less in the way of prior endocrine treatment. 3. Novel pathways: mTOR inhibitors. Everolimus, the orally available mTOR inhibitor, is now FDA approved for use in AI-refractory breast cancer based on the BOLERO-2 study which showed that adding everolimus improved PFS compared to ongoing AI therapy, alone. To date, genomic biomarkers have not lent themselves to clinical use for patient selection of mTOR inhibitor therapy. 4. Novel pathways: CDK4/6 inhibitors. Novel agents are targeting the CDK4/6 pathway in ER+ metastatic breast cancer, and show early promise in randomized phase II studies. 5. Use of estrogens as treatment for advanced breast cancer. Harkening back to observations from the 1950s and 1960s, investigators have shown in small phase II trials that estrogen therapy itself can achieve tumor regression and clinical benefit in ER+ metastatic breast cancer. 6. Genomic revolution. Full genome sequencing is now available for many ER+ advanced cancers, identifying frequent mtuations in many genes (PIK3CA, FGFR, IGFR, AKT, CCND1 and other genes that may lend themselves to targeted therapeutic approaches. In addition to these innovations in targeted the ER and related pathways, it is also becoming clear chemotherapy outcomes for women with ER+ breast cancer are effective, and often more effective than in the treatment of TNBC which is more often considered a “chemotherapy-treated” tumor. These advances and other insights into ER positive metastatic breast cancer will be discussed.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr ES09-1.

Abstract P6-11-09: Impact of tumor subtype on clinical features, treatment, and clinical outcomes among breast cancer patients with central nervous system disease

Background: Breast cancer is the second most common cancer associated with brain metastases. For some patients, central nervous system (CNS) progression is the primary clinical problem, and the optimal management of these patients remains a challenge. In this study we examined the differences in clinical characteristics, the features of CNS-directed therapy, and outcomes among breast cancer patients with brain metastases according to tumor subtype.

Methods: A retrospective series of 214 breast cancer patients with brain metastases treated at the Dana-Farber Cancer Institute from 1999-2011 was identified. Tumor subtype was classified as hormone receptor (HR)+ (ER+/PR+/HER2-), triple negative (ER-/PR-/HER2-) or HER2+ (HER2+, any HR). Descriptive analysis was performed; Chi-square, Kruskal-Wallis, and Kaplan-Meier methods were used to compare clinical characteristics, CNS-directed therapy features, and outcomes between groups.

Results: Median follow-up time since CNS progression was 8 months (0-117). Median age at CNS diagnosis was 52 years (30-82). Tumor subtype distribution was as following: 35% HR+, 36% HER2+, and 29% triple negative. Table 1 represents the clinical characteristics, CNS-directed therapy features, and outcomes according to tumor subtypes. More patients with triple negative disease (32%) had CNS involvement at presentation of metastatic disease. 8% of HER2+ patients had CNS as the only site of disease. A higher proportion of patients with HER2+ disease received more than one modality of CNS directed treatment as initial therapy. These patients also received more lines of CNS-directed therapy during the entire course of their disease. The median survival time after CNS progression differed by subtype; patients with HER2+ disease had the longest median survival times.

Conclusions: Tumor subtype appears to impact clinical presentation, type and number of CNS-directed therapies, and survival among patients with breast cancer with brain metastases.

Table 1 Tumor subtype HR+ (n = 74, 35%)HER2+ (n = 78, 36%)Triple negative (n = 62, 29%)P-valueBreakdown of treatment periods 0.2011999-200334%45%29% 2004-200628%17%31% 2007-201138%38%40% Clinical features at CNS disease presentationCNS disease at presentation of metastatic disease,%1522320.052Only site of metastatic disease,%181 Time from metastatic disease until CNS disease (median, min-max; months)16 (0-113)12 (0-65)6 (0-60)<0.001Type of CNS disease,%   0.004Brain only849589 Leptomeningeal disease only040 Brain and leptomeningeal disease16111 Number of CNS lesions,%   0.4141202921 2-3151413 4+625666 Unknown300 CNS-directed therapy1st CNS-directed therapy,% 0.126Surgery553 Whole brain radiotherapy725660 SRS896 Experimental drug135 More than one modality directed to CNS82721 Never received a CNS-directed therapy505 CNS-directed therapy (first and subsequent treatments combined),%    Surgery113360.003SRS154421<0.001Whole brain radiotherapy8788850.866Intrathecal therapy114150.085Systemic therapy3215<0.001Number of CNS-directed treatments (median, min-max)1 (0-6)2 (1-9)1 (0-5)<0.001Clinical outcomesSurvival times (median, min-max; months)6 (0-83)22 (1-117)4 (0-110)<0.001Events,%9697980.016

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-09.

A phase II study of bevacizumab in combination with vinorelbine and trastuzumab in HER2-positive metastatic breast cancer

We aimed to evaluate the efficacy and feasibility of combining trastuzumab/vinorelbine with bevacizumab in patients with first-or second-line HER2-positive, metastatic breast cancer (MBC). Eligible patients had HER2-positive measureable MBC, with no more than one prior line of chemotherapy, and were treated with trastuzumab (4 mg/kg × 2 mg/kg weekly thereafter), vinorelbine (25 mg/m(2) weekly), and bevacizumab (10 mg/kg every 2 weeks). Co-primary endpoints were (a) the proportion of patients alive and progression-free at 1 year and (b) safety profile/feasibility. Feasibility was defined as a rate of grade 3/4 non-hematologic toxicity attributable to protocol-based therapy <20 %. Twenty-nine patients were enrolled (n = 22 first-line, n = 7 second-line). Median age was 48 years (range 37-68). The median number of cycles received was 8 (1-23) and median duration on treatment was 7.4 months (range 1-22). The study was closed early due to higher-than-expected rates of grade 3/4 non-hematologic toxicities, with 50 events in 20 patients. A total of six patients (21 %) were taken off study for treatment-related toxicity. Most common treatment-related toxicities included fatigue (n = 7), febrile neutropenia (n = 4), and headache (n = 3). At 1 year, 8/22 first-line (36 %) and 2/7 second-line (29 %) patients were alive and progression-free. Median PFS was 9.9 months and 7.8 months in the first- and second-line cohorts, respectively. Objective responses were observed in 16/22 (73 %) and 5/7 (71 %) patients in the first- and second-line settings. Although the combination of vinorelbine, trastuzumab, and bevacizumab showed notable activity in HER2-positive MBC, the proportion of first-line patients alive and progression-free at 1 year was deemed unlikely to reach the pre-defined threshold for declaring success. Additionally, unacceptable toxicity was observed, at rates greater than previously reported with vinorelbine/trastuzumab or vinorelbine/bevacizumab doublet combinations.

Abstract P5-18-03: Clinicopathological features among patients with HER2-positive breast cancer with prolonged response to trastuzumab based therapy

Background: HER2-positivity is a predictor of benefit from trastuzumab (TRZ), but fails to depict the observed interpatient variability in terms of treatment (tx) duration. In this study we described the relationship between clinicopathological features and TRZ tx duration.

Methods: A retrospective consecutive series of 343 HER2+ breast cancer (BC) patients (pts) treated with TRZ at the Dana-Farber Cancer Institute from 1999–2008 was identified. 139 pts treated with 1st line TRZ-based tx were selected for analysis. Pts who received any non-TRZ prior tx for metastatic disease were excluded. TRZ tx duration was defined as time from start of 1st line therapy to the 1st day of 2nd line therapy or death. Central nervous system (CNS) progression with TRZ maintenance was not considered change of tx. Pts were divided equally into 3 groups based on the duration of 1st line tx distribution. Short-term responders (STR) were on the 1st line tx for &lt;7 months (m), intermediate responders (IR) 7–15m and long responders (LTR) for &gt;15m. An additional group of extremely LTR (ELTR) was defined as being in the 90th percentile of tx duration (&gt;37m). Descriptive analysis was performed; fisher exact test, Kruskal-Wallis and logistic regression methods were used to compare groups.

Results: Median follow-up time since metastatic diagnosis was 4 years (y) (range 0–11). Median age at diagnosis was 47y (22–83), 25% of stage I-III pts at diagnosis received adjuvant/neoadjuvant TRZ. The median disease free interval (DFI) was 20m (0–172), median number of metastatic sites was 2(1–5), 68% of pts had visceral disease. Median duration of 1st line tx was 10m (2–105). TRZ was given with CT in 86%, hormone tx in 6% and as monotherapy in 9%. 25% of pts developed CNS progression and continued tx. There were only small absolute differences for clinicopathological characteristics among STR, IR and LTR.

Responses to subsequent anti-HER2 therapy after treatment with trastuzumab-DM1 in women with HER2-positive metastatic breast cancer

BACKGROUND

Women with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC) can respond to multiple lines of anti-HER2 therapy. It is unknown whether these patients will derive further clinical benefit following treatment with trastuzumab-MCC-DM1 (T-DM1).

PATIENTS AND METHODS

We retrospectively identified HER2-positive MBC patients treated with T-DM1 and characterized outcomes during subsequent lines of anti-HER2 therapy. Response was determined by a blinded radiology review. Time-dependent analyses were carried out using Kaplan-Meier estimates.

RESULTS

We identified 23 patients treated with single-agent T-DM1 and report on the 20 patients who discontinued protocol therapy. All patients received trastuzumab-based metastatic therapy before initiation of T-DM1 [median 7 regimens (range 3-14)]. Of these 20 patients, 75% (15 of 20) received further therapy with or without anti-HER2 agents after discontinuing T-DM1. Partial response to either first- or second-subsequent line(s) of therapy was seen in 5 of 15 (33%) treated patients, including 33% (4 of 12) who received a regimen containing trastuzumab and/or lapatinib. Median durations of therapy to first- and second-subsequent regimens after T-DM1 were 5.5 and 6.4 months, respectively.

CONCLUSIONS

In heavily pretreated HER2-positive MBC patients, prior exposure to T-DM1 does not exhaust the potential benefit of ongoing anti-HER2 therapy with trastuzumab- and/or lapatinib-based regimens.

OT3-02-04: TBCRC 012: ABCDE, a Phase II Randomized Study of Adjuvant Bevacizumab, Metronomic Chemotherapy (CM), Diet and Exercise after Preoperative Chemotherapy for Breast Cancer

Background Patients (pts) with residual breast cancer after neoadjuvant chemotherapy are at increased risk of recurrence; no proven risk-reduction strategies exist, supporting exploration of novel therapies in the post-preoperative setting. Bevacizumab (B) combined with chemotherapy is active in metastatic disease; ongoing studies are exploring the efficacy of adjuvant combination chemotherapy and B. DFCI 05–055 (Mayer et al, ASCO 2007, 2008) demonstrated the feasibility of 1 year B after preoperative chemotherapy. Also, increasing data support risk reduction through lifestyle interventions (Segal, Ligibel et al, ASCO 2011). The ABCDE trial was designed to evaluate extended adjuvant B in a high risk post-preoperative cohort, and also assess the contribution of exercise to a dietary intervention.

Eligibility Criteria Eligible pts have HER2− breast cancer and have received preoperative anthracycline and/or taxane-based chemotherapy with residual invasive disease at surgery. Acceptable stages include: triple negative if preop stages I-III, or ER+/PR+ if stage III preop or IIB postop. Acceptable organ function and standard B exclusions apply. Registration must occur between 28–180 days after last surgery.

Specific Aims Primary endpoint is recurrence-free survival at a median follow-up of 6 years. Secondary endpoints include B pharmacogenomics, evaluation of the impact of exercise on quality of life and biomarkers associated with recurrence, and prospective examination of cardiac toxicity. Residual tissue-based predictors of outcome will be extensively explored, including PAM50, Ki67, and VEGF hypoxia signature.

Methods This is a 2 × 2 randomized study with a first randomization to 6 months (mo) B 15 mg/kg every 3 weeks (wks) plus 6 mo CM (C 50 mg daily, M 2.5 mg twice daily days 1, 2 each wk), followed by 2.5 years B 15 mg/kg every 6–8 wks, versus observation. A second randomization is to a 1 year telephone-based lifestyle intervention, offering dietary modification alone, or in combination with a structured exercise program.

Statistical Methods and Accrual Total sample size is 660 pts within the Translational Breast Cancer Research Consortium. Overall power is 0.80 to detect a hazard ratio of 0.59−0.68, depending on pt population. Accrual initiated early 2011 and is expected to continue for the next 36 months.

Conclusions Patients with residual disease after preoperative chemotherapy are at high risk of recurrence and have unmet medical needs. To our knowledge, this is the only trial testing a prolonged but less intensive adjuvant B schedule in this clinical setting. Results of this study could have critical implications for the management of this patient population and for the design of future clinical trials with anti-angiogenic agents.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT3-02-04.

CMF revisited in the 21st century

Over the last 35 years, classical CMF (combination chemotherapy with cyclophosphamide, methotrexate and fluorouracil) has been a milestone in the adjuvant treatment of women with breast cancer. However, after an early burst of success lasted just over 10 years, classical CMF has been supplanted by 'third-generation' regimens containing taxanes and anthracyclines. Questions have been raised in the past years concerning the true effectiveness of adjuvant CMF for specific subgroups of patients and particularly, recent retrospective data support the fact that the CMF might have a role in the treatment of patients with triple-negative breast cancer. One possible justification for supporting this role of CMF may be sought in the mechanism of action of drugs used in the regimen, as triple-negative cells may be sensitive to alkylating agents that cause double-strand breaks in DNA. The lesson learned from the CMF could lead us to identify new combinations of drugs that could include the optimal chemotherapy backbone for triple-negative breast cancer such as platinum compounds or alkylating agents or Poly (ADP-ribose) polymerase inhibitors. In conclusion, although we have learned a lot from the use of CMF, many questions are still open and hopefully stimulate our thinking, as clinicians, leading us to find new and more effective ways to treat breast cancer.

Impact of lapatinib plus trastuzumab versus single-agent lapatinib on quality of life of patients with trastuzumab-refractory HER2+ metastatic breast cancer

BACKGROUND

Progression-free survival (PFS) was significantly longer for the lapatinib plus trastuzumab (L+T) arm than for L alone in a phase III, randomized, open-label study of women with human epidermal growth factor receptor 2 positive metastatic breast cancer who had documented progression on at least one T-containing regimen in the metastatic setting. This analysis focused on impact of treatments on health-related quality of life (HRQOL).

METHODS

HRQOL was assessed using the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire. Changes from baseline and time to deterioration were analyzed in the intent-to-treat population.

RESULTS

Differences between the treatment arms in adjusted mean change from baseline favored the L+T arm, ranging from 0.0 to 4.1 (FACT-B), 1.0-4.0 [Functional Assessment of Cancer Therapy-General (FACT-G)], and 0.5-2.7 (Trial Outcome Index). Most differences were not statistically significant, except for FACT-G at week 12 (delta = 4.0, P = 0.037). Similar results were found in a sensitivity analysis that included HRQOL records up to patient withdrawal from original randomized treatment. The longer time to HRQOL deterioration in the L+T arm was not statistically significant (FACT-B hazard ratio, 0.82; 95% confidence interval 0.56-1.20).

CONCLUSION

The addition of lapatinib to trastuzumab prolonged PFS while improving or maintaining near-term HRQOL, suggesting a meaningful clinical benefit to patients.

Abstract P3-10-13: Prognostic Value of Genomic Analysis after Neoadjuvant Chemotherapy for Breast Cancer

Background

Oncotype DX® Recurrence Score® (RS) provides both predictive and prognostic information for estrogen receptor positive (ER+) breast cancer. Whether RS evolves after exposure to chemotherapy (C), or if RS post-neoadjuvant C has prognostic capacity for outcomes after bevacizumab, is not known. Methods

DFCI 05-055 treated patients (pts) with residual invasive disease following neoadjuvant C with sequential bevacizumab-containing regimens. Archival FFPE tissue was obtained from participants at 3 potential timepoints: pre-C core biopsy, post-C surgical residual disease, and core biopsy at time of systemic recurrence. Standard RS testing was performed on all samples.

Results

A total of 162 pts were enrolled on the parent study; of that, 118 samples from 80 pts were available for testing, including 48 pre-C core biopsies, 68 post-C surgical samples, and 34 paired samples before and after C. Comparison of ER/PR/HER2 testing by local IHC vs RT-PCR for the pre-C core biopsies showed excellent concordance. For the entire cohort of 80, 20 pts (25%) experienced distant recurrence (9 ER+, 11 ER-by IHC). RS risk distribution in this group included 14 high, 3 intermediate (int), and 3 low. High RS was positively associated with distant recurrence for the entire cohort (t-test p=0.04); this association remained consistent whether RS was tested pre-C (t-test p=0.07) or post-C (t-test p=0.02). Specimen characteristics of the 34 paired pre-C/post-C samples are described below. Of the 34 paired samples, RS was highly correlated before and after exposure to neoadjuvant C, (r=0.85, 95% CI 0.72-0.92), suggesting little, if any, change in RS from C exposure. Specific changes over time included 24 without change in RS group, 3 high to int, 1 high to low, 1 int to low, and 5 low to int. Testing by RT-PCR remained consistent for ER (r=0.91, 95% CI 0.82-0.95), PR (r=0.79, 95% CI 0.62-0.89) and HER2 (r=0.88, 95% CI 0.76-0.94) before and after neoadjuvant C. Two pts had biopsy samples from systemic recurrence; testing showed RS, ER, PR, HER remained in similar range from core biopsy to surgery to disease recurrence.

Conclusions

In this evaluation of samples pre-and post-neoadjuvant C, high RS determined either before or after neoadjuvant C predicted for disease recurrence after adjuvant bevacizumab treatment. RT-PCR and IHC values for ER/PR/HER2 were concordant. Paired RS and RT-PCR ER/PR/HER2 remained correlated despite interval exposure to neoadjuvant C. Post neoadjuvant C RS may provide valid prognostic information for breast cancer disease recurrence and warrants further study.

Specimen Characteristics for Paired Samples (n=34)

SABRE-B: an evaluation of paclitaxel and bevacizumab with or without sunitinib as first-line treatment of metastatic breast cancer

BACKGROUND

The vascular endothelial growth factor (VEGF) pathway can be targeted through VEGF neutralization or VEGF receptor (VEGFR) blockade using tyrosine kinase inhibition. Because laboratory models suggest that combining these approaches might be synergistic, we sought to evaluate the feasibility and efficacy of combining sunitinib with paclitaxel + bevacizumab (PB).

METHODS

Patients with human epidermal growth factor receptor 2 (HER2)-negative, metastatic breast cancer receiving first-line chemotherapy were randomized to PB or PB with sunitinib (PBS), with planned escalation of the sunitinib dose.

RESULTS

Forty-six patients were randomized to PB or PBS with sunitinib dosed at 25 mg p.o. daily. Patients receiving PBS encountered substantial toxicity that precluded adequate treatment. The percentage of patients with grade ≥3 adverse events was greater in the PBS arm than the PB arm (83% versus 57%), and sunitinib dosing was modified in 78% of patients, most often due to neutropenia, febrile neutropenia, and fatigue. In addition, 44% of patients had sunitinib dose reduction to 12.5 mg, and 39% required discontinuation. Patients receiving PBS had more bevacizumab treatment interruptions and discontinuations because of toxicity. Median treatment duration was longer in the PB arm compared with the PBS arm (14.1 versus 11.1 weeks), reflecting early treatment discontinuation of PBS. Because of poor tolerability of the addition of sunitinib to PB, the planned sunitinib dose escalation was halted and the study accrual was terminated.

CONCLUSION

Adding sunitinib to standard doses of bevacizumab plus paclitaxel for metastatic breast cancer is not feasible. Different strategies will be required to evaluate whether there is additional clinical benefit to combining VEGF/VEGFR-targeted agents.

Gastrointestinal and Cardiovascular Safety Profiles of Neratinib Monotherapy in Patients with Advanced ErbB2-Positive Breast Cancer

Background: In a phase 2 study, oral neratinib was administered to patients (pts) with advanced breast cancer in 2 cohorts, those with prior trastuzumab treatment (prior T, n=66) and those with no prior trastuzumab treatment (no prior T, n=70). Neratinib demonstrated robust antitumor activity with objective response rates of 26% and 51%, respectively, and was generally tolerable (Burstein et al. Cancer Res 2009;69:72S). Diarrhea, all grades, occurred in 89% of total pts. Characteristics of the diarrhea and left ventricular ejection fraction (LVEF) measurements are described. Methods: Pts were required to have ErbB2 gene amplification in tumor tissue as measured by fluorescence in situ hybridization by independent assessment. Serial LVEF measurements were made with a multigated acquisition scan or echocardiogram. Pts were ineligible if baseline LVEF was &lt;50%. Adverse events were graded based on the NCI Common Terminology Criteria, v 3.0. Pts received oral neratinib 240 mg daily. Results: Data collected by 18 Mar 2009 are reported; the median (range) duration of neratinib treatment was 4.5 (0.2-23.5) months for pts with prior T and 7.8 (0.5-24.2) months for pts with no prior T. Diarrhea, all grades occurred in 93% of the total population (prior T: 97%, no prior T: 89%); grade 3-4 diarrhea occurred in 21% of the total population (prior T: 30%, no prior T: 13%). Median times of onset were 2 and 3 days after first dose of neratinib, respectively, and median durations of diarrhea were 7 and 5 days. In study week 1, 86% and 73% of pts with prior T and no prior T, respectively, had diarrhea; this decreased to 12-14% in months 3 and 4 (Table). Diarrhea was the cause of dose interruptions in 36% of pts with prior T and 11% of pts with no prior T and of dose reductions in 30% of pts with prior T and 5% of pts with no prior T; only 1 pt (prior T) discontinued treatment due to diarrhea. Pts used anti-diarrheal medications for supportive therapy (prior T: 91%, no prior T: 67%). For LVEF measurements, there was little variation from baseline in most pts during the study. Four pts had at least 1 LVEF measurement &lt;50% (2 of these pts had measurements within the institutional range of normal). None had congestive heart failure. One of these pts had grade 3 atrioventricular block and grade 3 bradycardia, which were considered unrelated to neratinib. Discussion: Neratinib treatment was not associated with clinically significant cardiotoxicity. Pts who developed diarrhea with neratinib monotherapy had early onset, but frequency and severity decreased with time on study. Despite the high frequency of diarrhea with neratinib treatment, it was readily managed with supportive therapy and dose interruptions and/or reductions.Time Course of Diarrhea in ErbB2-Positive Breast Cancer Patients Treated With NeratinibStudy PeriodPrior T: No. on StudyPrior T: % With Diarrhea, All Grades*Prior T: % With Diarrhea, Gr 3-4*No Prior T: No. on StudyNo Prior T: % With Diarrhea, All Grades*No Prior T: % With Diarrhea, Gr 3-4*Week 166861770737Week 2-466611170436Month 260331066152Month 34713060120Month 44312058140*For pts with multiple toxicity grades in a period, the maximum grade was reported.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5096.

Tolerability of and adherence to combination oral therapy with gefitinib and capecitabine in metastatic breast cancer

PURPOSE

This phase I study explored gefitinib (G) and capecitabine (C) in metastatic breast cancer (MBC).

METHODS

Sequential cohorts (n = 3) received G and escalating C on a 14 day on/7 day off schedule, with a validation cohort (n = 10) at the maximum tolerated dose (MTD). Dose limiting toxicity (DLT) was defined in cycle 1. The primary endpoint was safety; secondary endpoints included response and adherence.

RESULTS

About 19 patients were treated for a median of 5 cycles. No patients in sequential cohorts experienced DLT; C MTD was 2,000 mg/m(2)/day when paired with daily G 250 mg. In the validation cohort, four experienced serious toxicities, including diarrhea, mucositis, and palmarplantar dysesthesia. At the MTD, 6 (46%) required a C dose reduction, and 3 (23%) came off study for toxicity. One partial response was observed (8%, 95% CI 0.2-38.5%); five had stable disease >24 weeks (26, 95% CI 9-51%). Patients missed few drug doses, with the suggestion of overadherence to therapy.

CONCLUSIONS

In this phase I study of G and C in MBC, a C MTD was identified, and significant toxicity was observed. About 8% demonstrated a response, with 26% maintaining stable disease. The possibility of overadherence, as suggested in this study, may have implications for other trials of oral antineoplastic therapy.

Single-agent lapatinib for HER2-overexpressing advanced or metastatic breast cancer that progressed on first- or second-line trastuzumab-containing regimens

BACKGROUND

This phase II study evaluated the efficacy and safety of lapatinib in patients with human epidermal growth factor receptor 2 (HER2)-positive advanced or metastatic breast cancer that progressed during prior trastuzumab therapy.

PATIENTS AND METHODS

Women with stage IIIB/IV HER2-overexpressing breast cancer were treated with single-agent lapatinib 1250 or 1500 mg once daily after protocol amendment. Tumor response according to RECIST was assessed every 8 weeks. HER2 expression was assessed in tumor tissue by immunohistochemistry and FISH.

RESULTS

Seventy-eight patients were enrolled in the study. Investigator and independent review response rates [complete response (CR) or partial response (PR)] were 7.7% and 5.1%, and clinical benefit rates (CR, PR, or stable disease for >or=24 weeks) were 14.1% and 9.0%, respectively. Median time to progression was 15.3 weeks by independent review, and median overall survival was 79 weeks. The most common treatment-related adverse events were rash (47%), diarrhea (46%), nausea (31%), and fatigue (18%).

CONCLUSIONS

Single-agent lapatinib has clinical activity with manageable toxic effects in HER2-overexpressing breast cancer that progressed on trastuzumab-containing therapy. Studies of lapatinib-based combination regimens with chemotherapy and other targeted therapies in metastatic and earlier stages of breast cancer are warranted.

A phase I study of vandetanib and metronomic chemotherapy in advanced breast cancer

Abstract #906

Background: Vandetanib (V) is an oral tyrosine kinase inhibitor of vascular endothelial growth factor (VEGF) receptors 2 and 3 and epidermal growth factor receptor. Metronomic chemotherapy, continuous low-dose oral cyclophosphamide and methotrexate (CM), has activity in combination with anti-angiogenic treatments. We sought to define the safety and tolerability of all-oral combination therapy with V and CM in advanced breast cancer.&#x2028; Patients and Methods: Eligible patients (pts) had stage IV breast cancer; measurable disease was not required and stable brain metastases were acceptable. Up to 4 prior chemotherapy regimens were allowable, as was prior bevacizumab. Pts with systemic anticoagulation or QTc abnormalities were excluded. Three sequential dose escalation cohorts of approximately 8 pts were enrolled. All pts received CM (C 50 mg PO qd, M 2.5 mg PO d1-2 q week), and V in 3 dose-escalation cohorts: 100 mg qd (Cohort 1), 200 mg qd (Cohort 2), and 300 mg qd (Cohort 3). Pts received V + CM until progression or unacceptable toxicity; dose adjustments were made for treatment related toxicity. The primary endpoint was safety and toxicity of the regimen; secondary endpoints included response rate, non-invasive vascular analysis of hypertension, and platelet proteomics.&#x2028; Results: 24 pts (median age 49 years) entered the study. 83% had visceral disease, 92% had received prior chemotherapy for metastatic disease (median number of regimens, 2), and 38% had received prior bevacizumab. Median cycles of therapy completed was 2 (range 1-8); median number of weeks on study was 8 (range 2-33). Toxicities in Cohorts 1 and 2 were generally manageable, and most commonly consisted of diarrhea, nausea, fatigue, abnormal hepatic function, and hyperglycemia. Despite fewer cycles of drug exposure, increased toxicity was observed in Cohort 3, including 3 episodes of dose limiting toxicity (mucositis/rash, 1; abnormal hepatic function, 2). One-third of pts required V dose reduction, and 21% of pts came off study for toxicities including cerebrovascular event (1), pulmonary embolus (1), rash (1), abnormal hepatic function (1), and myocarditis (1). Moderate hypertension was observed in 42% of pts, with a single grade 3 event. Of the 20 response-evaluable pts, 2 (10%, 95% CI 1.2 – 31.7 %) demonstrated partial response, one lasting over 30 weeks, and 3 had stable disease &gt; 24 wks (15%, 95% CI 3.2 – 37.9%). Results from correlative vascular hypertension analyses and platelet proteomics will be presented.&#x2028; Conclusions: The all-oral regimen of V + CM was tolerable at a maximum dose of V 200 mg qd. Dose-limiting toxicity was seen in the V 300 mg cohort. Modest clinical activity in this heavily pretreated population was observed, and supports further investigation of this anti-angiogenic regimen in advanced breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 906.

Dose-dense (DD) doxorubicin and cyclophosphamide (AC) followed by weekly paclitaxel (P) with trastuzumab (T) and lapatinib (L) in HER2/neu-positive breast cancer is not feasible due to excessive diarrhea: updated results

Abstract #2108

Background: DD q 2 weekly (w) AC → P + T x 1 year (y) has an acceptable safely profile w/ congestive heart failure (CHF) rate of 1/70 pts (Dang, JCO 2008). Lapatinib (L) is effective in HER2 (+) BC. We conducted a pilot study of dd AC → w P + T + L to determine its feasibility and cardiac safety.&#x2028; Methods: Enrolled pts had HER2 (+) BC; LVEF &gt; 50%. Rx consisted of AC at 60/600 mg/m2 x 4 q 2 w (w/ pegfilgrastim 6 mg day 2) → P at 80 mg/m2 x 12 q w + T x 1 y; L (1000 mg daily beginning w/ P + T and continued x 1 y). MUGA is obtained at baseline and at months (mo) 2, 6, 9, and 18. Rx is considered feasible if 1) &gt; 80% pts can complete the PTL phase without a dose delay or reduction and 2) the cardiac event rate (CHF or cardiac death) is &lt; 4%. Pts can remain on-Rx w/ one dose reduction of L (1000 mg → 750 mg) for a G 3 event or &lt; G 3 toxicity (unacceptable).&#x2028; Results: From March 2007 to April 2008, we enrolled 95 pts. Median (med) age was 45 years (range, 28-73). At a med follow-up of 7 months, 90 are evaluable. Of the 90 pts, 34 (37%) withdrew from study during the PTL phase; 29 for a 2nd event of G 3 or unacceptable &lt; G 3 toxicities (15 G 3 diarrhea, 4 G 1/2 diarrhea, 1 G 3 rash, 2 G 2 rash, 1 G 3 dyspnea and also had G 3 diarrhea, 1 G 3 ↑QTc also had G 3 diarrhea, 1 G 3 ↑ALT also had G 3 diarrhea, 1 G 3 paronychia, 1 G 3 pneumonitis, 1 asymptomatic LVEF ↓, 1 myocarditis) and 5 for other reasons (2 personal reason, 1 PCP pneumonia, 1 progression, 1 P hypersensitivity). Overall, 25/90 (27%) pts had G 3 diarrhea and 31/90 (34%) pts required a dose reduction of lapatinib. Med LVEF at baseline is 67% (N=95), at mo 2 is 68% (N=90), at mo 6 is 65% (N=53), and mo 9 is 65% (N=28). To date there are no patient drop-outs due to significant LVEF declines after dd AC; one patient dropped during PTL out due to an asymptomatic LVEF decline.&#x2028; Discussion: L at 1000 mg/day is not feasible combined w/ weekly P and T by protocol stipulation (&gt; 20% pts required L dose reduction) primarily due to excessive G 3 diarrhea. These results have led to the modification of Design 2 (Arm D) of ALTTO. We will report updated results.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2108.

Second consensus on medical treatment of metastatic breast cancer

The present consensus manuscript defines evidence-based recommendations for state-of-the-art treatment of metastatic breast cancer depending on disease-associated and biologic variables.

Isolated central nervous system metastases in patients with HER2-overexpressing advanced breast cancer treated with first-line trastuzumab-based therapy

PURPOSE

The aim of this study was to characterize the prevalence and predictors of central nervous system (CNS) metastasis among women with HER2-overexpressing metastatic breast cancer receiving trastuzumab-based therapy.

METHODS

The frequency and time course of isolated CNS progression were characterized among women with HER2-positive metastatic breast cancer, receiving chemotherapy with or without trastuzumab as first-line treatment for metastatic disease in two clinical trials. The first trial was a multicenter randomized phase III study of chemotherapy (doxorubicin/cyclophosphamide or paclitaxel) +/- trastuzumab, and the second was a multicenter phase II trial of vinorelbine + trastuzumab. All patients had measurable disease and were free of symptomatic CNS disease at initiation of study treatment.

RESULTS

Nearly 10% of patients receiving trastuzumab in combination with chemotherapy developed isolated CNS metastases as first site of tumor progression. Progression in the CNS tended to be a later event than progression at other sites among women receiving trastuzumab-based therapy. Trastuzumab-based treatment did not substantially delay onset of CNS metastases as initial site of progression. Following diagnosis with primary breast cancer, tumors with HER2 gene amplification tend to be associated with greater risk of isolated CNS progression compared with those lacking gene amplification.

CONCLUSIONS

Patients with HER2-overexpressing metastatic breast cancer are at risk for isolated CNS progression, reflecting improved peripheral tumor control and patient survival through use of trastuzumab-based therapy, and a relative lack of CNS activity with trastuzumab. Clinicians should be aware of this association. Better treatments for CNS recurrences are needed.

Side effects of chemotherapy and combined chemohormonal therapy in women with early-stage breast cancer

The decision to receive chemotherapy or chemohormonal therapy involves careful consideration of both the potential benefits and possible risks of therapy. There are substantial short- and long-term side effects from chemotherapy. By convention, short-term side effects include those toxic effects encountered during chemotherapy, while long-term side effects include later complications of treatment arising after the conclusion of adjuvant chemotherapy. These side effects vary, depending on the specific agents used in the adjuvant regimen as well as on the dose used and the duration of treatment. There is also considerable variability in side effect profile across individuals. This review will focus on the short- and long-term toxicity seen with the most commonly used adjuvant chemotherapy and chemohormonal therapy regimens.

New combinations with Herceptin in metastatic breast cancer

Preclinical data indicate that trastuzumab (Herceptin) has the potential for synergistic or additive effects in combination with therapies including chemotherapy and hormonal agents, providing the rationale for a number of clinical trials in women with HER2-positive metastatic breast cancer. A recently reported phase II trial has demonstrated that trastuzumab plus vinorelbine is both effective (overall response rate 75%) and well tolerated, with the major side effects being typical of single-agent vinorelbine. Other combinations of trastuzumab with a variety of other chemotherapeutic and hormonal agents are also being assessed. In an effort to overcome the cardiotoxicity observed with trastuzumab plus doxorubicin in the pivotal phase III trial, combination regimens involving potentially less toxic anthracyclines such as epirubicin and liposomal formulations of doxorubicin are ongoing. In addition, trials are investigating whether trastuzumab can reverse the resistance to hormonal therapy that develops in most women with metastatic breast cancer. These and other studies will identify the regimens that produce the best outcomes with the fewest possible side effects in women with HER2-positive breast cancer.

Gene therapy for rheumatoid arthritis

Gene therapy was initially conceived of as a means of replacing defective genes in monogenic disorders such as cystic fibrosis or hemophilia, but has rapidly progressed into areas of medicine that involve a wide range of diseases including cancer, neurodegenerative disorders and autoimmunity. Elucidation of some of the cellular and molecular mechanisms implicated in the pathogenesis of joint inflammation and cartilage and bone destruction in inflammatory joint diseases such as rheumatoid arthritis (RA) have revealed novel targets for gene therapy. Strategies include the inhibition of pro-inflammatory cytokines, blockade of cartilage-degrading enzymes, inhibition of synovial cell activation or apoptosis of synovial cells, and manipulation of the Th1-Th2 cytokine balance. Both viral and non-viral gene transfer vector systems have been used to deliver therapeutic genes systemically or directly to arthritic joints by ex vivo as well as in vivo administration. Animal models of RA have been essential not only for better understanding the mechanisms of RA but also in serving as basic experimental tools to evaluate candidate gene products with anti-arthritic properties and develop therapeutic strategies.

New cytotoxic agents and schedules for advanced breast cancer

Cytotoxic chemotherapy is important for treatment of women with hormone-insensitive or hormone-refractory advanced breast cancer. A variety of agents are effective, alone or in combination. The clinical activity and side effects of many agents, as well as principles for use of chemotherapy, are reviewed. Recent advances in chemotherapy for breast cancer include important studies on the role of dose-intensity, modifications of available agents to reduce side effects, and the availability of oral chemotherapeutics. Finally, the combination of chemotherapy with novel biological agents may improve outcomes for women with certain types of breast cancer. The growing availability of such biological therapies given in combination with chemotherapy may mean better survival in the future for women with advanced breast cancer.

Clinical Activity of Trastuzumab and Vinorelbine in Women With HER2-Overexpressing Metastatic Breast Cancer

PURPOSE: To determine the response rate and toxicity profile of trastuzumab administered concurrently with weekly vinorelbine in women with HER2-overexpressing advanced breast cancer.

PATIENTS AND METHODS: Forty women with HER2-positive (+3 by immunohistochemistry, n = 30; +2 or positive, n = 10) breast cancer were enrolled onto a study of trastuzumab (4 mg/kg × 1, 2 mg/kg weekly thereafter) and vinorelbine (25 mg/m2 weekly, with dose adjusted each week for neutrophil count). Eighty-two percent of women had received prior chemotherapy as part of adjuvant (30%), metastatic (25%), or both (28%) treatment, including substantial portions of patients who had previously received either anthracyclines (20%), taxanes (15%), or both types (38%) of chemotherapy.

RESULTS: Responses were observed in 30 of 40 patients (overall response rate, 75%, conditional corrected 95% confidence interval, 57% to 89%). The response rate was 84% in patients treated with trastuzumab and vinorelbine as first-line therapy for metastatic disease, and 80% among HER2 +3 positive patients. High response rates were also seen in women treated with second- or third-line therapy, and among patients previously treated with anthracyclines and/or taxanes. Combination therapy was feasible; patients received concurrent trastuzumab and vinorelbine in 93% of treatment weeks. Neutropenia was the only grade 4 toxicity. No patients had symptomatic heart failure. Grade 2 cardiac toxicity was observed in three patients. Prior cumulative doxorubicin dose in excess of 240 mg/m2 and borderline pre-existing cardiac function were associated with grade 2 cardiac toxicity.

CONCLUSION: Trastuzumab in combination with vinorelbine is highly active in women with HER2-overexpressing advanced breast cancer and is well tolerated.