Time trends in real-world treatment patterns and survival in patients diagnosed with de novo HER2+ metastatic breast cancer: an analysis of the SONABRE registry

PURPOSE

The aim was to determine whether the real-world first-line progression-free survival (PFS) of patients diagnosed with de novo human epidermal growth factor receptor 2 positive (HER2+) advanced breast cancer (ABC) has improved since the introduction of pertuzumab in 2013. In addition to PFS, we aimed to determine differences in overall survival (OS) and the use of systemic and locoregional therapies.

METHODS

Included were patients systemically treated for de novo HER2+ ABC in ten hospitals in 2008-2017 from the SONABRE Registry (NCT-03577197). First-line PFS and OS in 2013-2017 versus 2008-2012 was determined using Kaplan-Meier analyses and multivariable Cox proportional hazards modelling. First-given systemic therapy and the use of locoregional therapy within the first year following diagnosis were determined per period of diagnosis.

RESULTS

Median and five-year PFS were 26.6 months and 24% in 2013-2017 (n = 85) versus 14.5 months and 10% in 2008-2012 (n = 81) (adjusted HR = 0.65, 95%CI:0.45-0.94). Median and five-year OS were 61.2 months and 51% in 2013-2017 versus 26.1 months and 28% in 2008-2012 (adjusted HR = 0.55, 95%CI:0.37-0.81). Of patients diagnosed in 2013-2017 versus 2008-2012, 84% versus 60% received HER2-targeted therapy and 59% versus 0% pertuzumab-based therapy as first-given therapy. Respectively, 27% and 23% of patients underwent locoregional breast surgery, and 6% and 7% surgery of a metastatic site during the first year following diagnosis.

CONCLUSION

The prognosis of patients with de novo HER2 + ABC has improved considerably. Since 2013 one in four patients were alive and free from progression on first-given therapy for at least five years.

PD-L1 blockade in combination with carboplatin as immune induction in metastatic lobular breast cancer: the GELATO trial

Invasive lobular breast cancer (ILC) is the second most common histological breast cancer subtype, but ILC-specific trials are lacking. Translational research revealed an immune-related ILC subset, and in mouse ILC models, synergy between immune checkpoint blockade and platinum was observed. In the phase II GELATO trial ( NCT03147040 ), patients with metastatic ILC were treated with weekly carboplatin (area under the curve 1.5 mg ml-1 min-1) as immune induction for 12 weeks and atezolizumab (PD-L1 blockade; triweekly) from the third week until progression. Four of 23 evaluable patients had a partial response (17%), and 2 had stable disease, resulting in a clinical benefit rate of 26%. From these six patients, four had triple-negative ILC (TN-ILC). We observed higher CD8+ T cell infiltration, immune checkpoint expression and exhausted T cells after treatment. With this GELATO trial, we show that ILC-specific clinical trials are feasible and demonstrate promising antitumor activity of atezolizumab with carboplatin, particularly for TN-ILC, and provide insights for the design of highly needed ILC-specific trials.

Margetuximab Versus Trastuzumab in Patients With Previously Treated HER2-Positive Advanced Breast Cancer (SOPHIA): Final Overall Survival Results From a Randomized Phase 3 Trial

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Final overall survival (OS) in SOPHIA (ClinicalTrials.gov identifier: NCT02492711), a study of margetuximab versus trastuzumab, both with chemotherapy, in patients with previously treated human epidermal growth factor receptor 2-positive advanced breast cancer, is reported with updated safety. Overall, 536 patients in the intention-to-treat population were randomly assigned to margetuximab (15 mg/kg intravenously once every 3 weeks; n = 266) plus chemotherapy or trastuzumab (6 mg/kg intravenously once every 3 weeks after a loading dose of 8 mg/kg; n = 270) plus chemotherapy. Primary end points were progression-free survival, previously reported, and OS. Final OS analysis was triggered by 385 prespecified events. The median OS was 21.6 months (95% CI, 18.89 to 25.07) with margetuximab versus 21.9 months (95% CI, 18.69 to 24.18) with trastuzumab (hazard ratio [HR], 0.95; 95% CI, 0.77 to 1.17; P = .620). Preplanned, exploratory analysis of CD16A genotyping suggested a possible improvement in OS for margetuximab in CD16A-158FF patients versus trastuzumab (median OS, 23.6 v 19.2 months; HR, 0.72; 95% CI, 0.52 to 1.00) and a possible improvement in OS for trastuzumab in CD16A-158VV patients versus margetuximab (median OS, 31.1 v 22.0 months; HR, 1.77; 95% CI, 1.01 to 3.12). Margetuximab safety was comparable with trastuzumab. Final overall OS analysis did not demonstrate margetuximab advantage over trastuzumab. Margetuximab studies in patients with human epidermal growth factor receptor 2-positive breast cancer with different CD16A allelic variants are warranted.

Diagnostic Accuracy of Radioactive Iodine Seed Placement in the Axilla With Sentinel Lymph Node Biopsy After Neoadjuvant Chemotherapy in Node-Positive Breast Cancer

Importance

Several less-invasive staging procedures have been proposed to replace axillary lymph node dissection (ALND) after neoadjuvant chemotherapy (NAC) in patients with initially clinically node-positive (cN+) breast cancer, but these procedures may fail to detect residual disease. Owing to the lack of high-level evidence, it is not yet clear which procedure is most optimal to replace ALND.

Objective

To determine the diagnostic accuracy of radioactive iodine seed placement in the axilla with sentinel lymph node biopsy (RISAS), a targeted axillary dissection procedure.

Design, Setting, and Participants

This was a prospective, multicenter, noninferiority, diagnostic accuracy trial conducted from March 1, 2017, to December 31, 2019. Patients were included within 14 institutions (general, teaching, and academic) throughout the Netherlands. Patients with breast cancer clinical tumor categories 1 through 4 (cT1-4; tumor diameter <2 cm and up to >5 cm or extension to the chest wall or skin) and pathologically proven positive axillary lymph nodes (ie, clinical node categories cN1, metastases to movable ipsilateral level I and/or level II axillary nodes; cN2, metastases to fixed or matted ipsilateral level I and/or level II axillary nodes; cN3b, metastases to ipsilateral level I and/or level II axillary nodes with metastases to internal mammary nodes) who were treated with NAC were eligible for inclusion. Data were analyzed from July 2020 to December 2021.

Intervention

Pre-NAC, the marking of a pathologically confirmed positive axillary lymph node with radioactive iodine seed (MARI) procedure, was performed and after NAC, sentinel lymph node biopsy (SLNB) combined with excision of the marked lymph node (ie, RISAS procedure) was performed, followed by ALND.

Main Outcomes and Measures

The identification rate, false-negative rate (FNR), and negative predictive value (NPV) were calculated for all 3 procedures: RISAS, SLNB, and MARI. The noninferiority margin of the observed FNR was 6.25% for the RISAS procedure.

Results

A total of 212 patients (median [range] age, 52 [22-77] years) who had cN+ breast cancer underwent the RISAS procedure and ALND. The identification rate of the RISAS procedure was 98.2% (223 of 227). The identification rates of SLNB and MARI were 86.4% (197 of 228) and 94.1% (224 of 238), respectively. FNR of the RISAS procedure was 3.5% (5 of 144; 90% CI, 1.38-7.16), and NPV was 92.8% (64 of 69; 90% CI, 85.37-97.10), compared with an FNR of 17.9% (22 of 123; 90% CI, 12.4%-24.5%) and NPV of 72.8% (59 of 81; 90% CI, 63.5%-80.8%) for SLNB and an FNR of 7.0% (10 of 143; 90% CI, 3.8%-11.6%) and NPV of 86.3% (63 of 73; 90% CI, 77.9%-92.4%) for the MARI procedure. In a subgroup of 174 patients in whom SLNB and the MARI procedure were successful and ALND was performed, FNR of the RISAS procedure was 2.5% (3 of 118; 90% CI, 0.7%-6.4%), compared with 18.6% (22 of 118; 90% CI, 13.0%-25.5%) for SLNB (P < .001) and 6.8% (8 of 118; 90% CI, 3.4%-11.9%) for the MARI procedure (P = .03).

Conclusions and Relevance

Results of this diagnostic study suggest that the RISAS procedure was the most feasible and accurate less-invasive procedure for axillary staging after NAC in patients with cN+ breast cancer.

The implementation of CDK 4/6 inhibitors and its impact on treatment choices in HR+/HER2- advanced breast cancer patients: A study of the Dutch SONABRE Registry

In August 2017, cyclin‐dependent kinase 4/6 (CDK4/6) inhibitors combined with endocrine therapy have been reimbursed in the Netherlands for patients with hormone receptor positive (HR+), HER2 negative (HER2−) advanced breast cancer (ABC). This study evaluates the implementation of CDK4/6 inhibitors and changes in treatment choices in the Netherlands. All patients diagnosed with HR+/HER2− ABC in 2009 to 2018 in seven hospitals were selected from the Southeast Netherlands Advanced Breast cancer (SONABRE) registry. The 2‐year cumulative use of CDK4/6 inhibitors since reimbursement date (August 2017) was assessed using competing‐risk methodology in two cohorts. The first cohort included patients with ABC diagnosis between August 2017 and December 2018. The second cohort included patients with ABC diagnosis between 2009 and August 2017, and still alive on August 1, 2017. In addition, treatment choices in the first three lines of therapy in calendar years 2009 to 2018 were evaluated for the total study population. Among patients diagnosed since August 2017 (n = 214), 50% (95% confidence interval [CI] = 43‐57) received CDK4/6 inhibitors within 2 years beyond diagnosis. Of eligible patients diagnosed before August 2017 (n = 417), 31% (95% CI = 27‐36) received CDK4/6 inhibitors within 2 years following reimbursement. Another 20% of both cohorts are still CDK4/6 inhibitor naïve and on first‐line therapy. The use of chemotherapy decreased in first two lines of therapy between 2009 and 2018 (first‐line: 29%‐13%; second‐line: 26%‐19%). The implementation rate of CDK4/6 inhibitors since reimbursement is currently 50% within 2 years beyond diagnosis and is expected to increase further. The implementation of targeted therapy decreased the use of chemotherapy as first‐line therapy.

What's new?

In the Netherlands, inhibitors of cyclin‐dependent kinase 4/6 (CDK 4/6) are eligible for reimbursement by health insurers. The present report describes implementation patterns of CDK4/6 inhibitors for the treatment of advanced breast cancer since 2017, based on data and observations collected from seven hospitals across the Southeast Netherlands. Analyses show that about half of patients with HR+/HER2‐ metastatic breast cancer are treated with CDK4/6 inhibitors. Following the implementation of these therapies, use of first‐line chemotherapy decreased significantly. Reduced chemotherapy use may have beneficial effects on quality of life for patients, adding value to overall gains in survival.

Intestinal Microbiota in Postmenopausal Breast Cancer Patients and Controls

Simple Summary

Besides the already known factors that increase the risk of breast cancer, like hormonal treatment, heredity, and obesity, growing evidence exists that intestinal microbiota can influence breast cancer carcinogenesis. Current clinical information into the role of the intestinal microbiota in breast cancer patients is limited. This study aimed to see whether there are differences in intestinal microbiota richness, diversity, and composition between oestrogen receptor positive breast cancer patients and controls. We concluded that the intestinal microbiota richness, diversity, and composition were not different between breast cancer patients and postmenopausal controls. An increased relative abundance of Dialister and Veillonellaceae was observed in breast cancer patients scheduled for adjuvant treatment, which might be caused by a relative decrease in other bacteria due to surgery associated factors rather than an absolute increase. For future studies, we strongly advise a more homogeneous group of breast cancer patients of preferably treatment-naive patients.

Abstract

Background: Previous preclinical and clinical research has investigated the role of intestinal microbiota in carcinogenesis. Growing evidence exists that intestinal microbiota can influence breast cancer carcinogenesis. However, the role of intestinal microbiota in breast cancer needs to be further investigated. This study aimed to identify the microbiota differences between postmenopausal breast cancer patients and controls. Patients and methods: This prospective cohort study compared the intestinal microbiota richness, diversity, and composition in postmenopausal histologically proven ER+/HER2- breast cancer patients and postmenopausal controls. Patients scheduled for (neo)adjuvant adriamycin, cyclophosphamide (AC), and docetaxel (D), or endocrine therapy (tamoxifen) were prospectively enrolled in a multicentre cohort study in the Netherlands. Patients collected a faecal sample and completed a questionnaire before starting systemic cancer treatment. Controls, enrolled from the National Dutch Breast Cancer Screening Programme, also collected a faecal sample and completed a questionnaire. Intestinal microbiota was analysed by amplicon sequencing of the 16S rRNA V4 gene region. Results: In total, 81 postmenopausal ER+/HER2- breast cancer patients and 67 postmenopausal controls were included, resulting in 148 faecal samples. Observed species richness, Shannon index, and overall microbial community structure were not significantly different between breast cancer patients and controls. There was a significant difference in overall microbial community structure between breast cancer patients scheduled for adjuvant treatment, neoadjuvant treatment, and controls at the phylum (p = 0.042) and genus levels (p = 0.015). Dialister (p = 0.001) and its corresponding family Veillonellaceae (p = 0.001) were higher in patients scheduled for adjuvant treatment, compared to patients scheduled for neoadjuvant treatment. Additional sensitivity analysis to correct for the potential confounding effect of prophylactic antibiotic use, indicated no differences in microbial community structure between patients scheduled for neoadjuvant systemic treatment, adjuvant systemic treatment, and controls at the phylum (p = 0.471) and genus levels (p = 0.124). Conclusions: Intestinal microbiota richness, diversity, and composition are not different between postmenopausal breast cancer patients and controls. The increased relative abundance of Dialister and Veillonellaceae was observed in breast cancer patients scheduled for adjuvant treatment, which might be caused by a relative decrease in other bacteria due to prophylactic antibiotic administration rather than an absolute increase.

Healthcare Use during the Last Six Months of Life in Patients with Advanced Breast Cancer

Simple Summary

In the last decades, new treatment options for advanced (breast) cancer have resulted in increased use of health care resources near the end of life. We assessed health care use near the end of life of patients with advanced breast cancer (ABC). In this study, we have shown that ICU admission, and CPR occurred rarely during the last six months of life of ABC patients. However, hospital admissions occurred often, especially in patients who received new chemotherapy within 30 days of end of life. Those patients were also more likely to die in the hospital. However, death was most often due to disease progression. To improve quality of life near the end of life of advanced breast cancer patients, it is vital to develop tools to help clinicians identify those patients who will benefit from chemotherapy at the end of life.

Abstract

New treatment options in cancer have resulted in increased use of health care resources near the end of life. We assessed health care use near the end of life of patients with advanced breast cancer (ABC). From the Southeast Netherlands Breast cancer (SONABRE) registry, we selected all deceased patients diagnosed with ABC in Maastricht University Medical Center between January 2007 and October 2017. Frequency of health care use in the last six months of life was described and predictors for health care use were assessed. Of 203 patients, 76% were admitted during the last six months, 6% to the intensive care unit (ICU) and 2% underwent cardiopulmonary resuscitation (CPR). Death in hospital occurred in 25%. Nine percent of patients received a new line of chemotherapy ≤30 days before death, which was associated with age <65 years and <1 year survival since diagnosis of metastases. In these patients, the hospital admission rate was 95%, of which 79% died in the hospital, mostly due to progressive disease (80%). In conclusion, the frequency of ICU-admission, CPR or a new line of chemotherapy ≤30 days before death was low. Most patients receiving a new line of chemotherapy ≤30 days before death, died in the hospital.

Modular design patterns for hybrid learning and reasoning systems

The unification of statistical (data-driven) and symbolic (knowledge-driven) methods is widely recognized as one of the key challenges of modern AI. Recent years have seen a large number of publications on such hybrid neuro-symbolic AI systems. That rapidly growing literature is highly diverse, mostly empirical, and is lacking a unifying view of the large variety of these hybrid systems. In this paper, we analyze a large body of recent literature and we propose a set of modular design patterns for such hybrid, neuro-symbolic systems. We are able to describe the architecture of a very large number of hybrid systems by composing only a small set of elementary patterns as building blocks. The main contributions of this paper are: 1) a taxonomically organised vocabulary to describe both processes and data structures used in hybrid systems; 2) a set of 15+ design patterns for hybrid AI systems organized in a set of elementary patterns and a set of compositional patterns; 3) an application of these design patterns in two realistic use-cases for hybrid AI systems. Our patterns reveal similarities between systems that were not recognized until now. Finally, our design patterns extend and refine Kautz’s earlier attempt at categorizing neuro-symbolic architectures.

MRI-Based Radiomics Analysis for the Pretreatment Prediction of Pathologic Complete Tumor Response to Neoadjuvant Systemic Therapy in Breast Cancer Patients: A Multicenter Study

This retrospective study investigated the value of pretreatment contrast-enhanced Magnetic Resonance Imaging (MRI)-based radiomics for the prediction of pathologic complete tumor response to neoadjuvant systemic therapy in breast cancer patients. A total of 292 breast cancer patients, with 320 tumors, who were treated with neo-adjuvant systemic therapy and underwent a pretreatment MRI exam were enrolled. As the data were collected in two different hospitals with five different MRI scanners and varying acquisition protocols, three different strategies to split training and validation datasets were used. Radiomics, clinical, and combined models were developed using random forest classifiers in each strategy. The analysis of radiomics features had no added value in predicting pathologic complete tumor response to neoadjuvant systemic therapy in breast cancer patients compared with the clinical models, nor did the combined models perform significantly better than the clinical models. Further, the radiomics features selected for the models and their performance differed with and within the different strategies. Due to previous and current work, we tentatively attribute the lack of improvement in clinical models following the addition of radiomics to the effects of variations in acquisition and reconstruction parameters. The lack of reproducibility data (i.e., test-retest or similar) meant that this effect could not be analyzed. These results indicate the need for reproducibility studies to preselect reproducible features in order to properly assess the potential of radiomics.

Direct Medical Costs of Advanced Breast Cancer Treatment: A Real-World Study in the Southeast of The Netherlands

OBJECTIVES

Policy makers increasingly seek to complement data from clinical trials with information from routine care. This study aims to provide a detailed account of the hospital resource use and associated costs of patients with advanced breast cancer in The Netherlands.

METHODS

Data from 597 patients with advanced breast cancer, diagnosed between 2010 and 2014, were retrieved from the Southeast Netherlands Advanced Breast Cancer Registry. Database lock for this study was in October 2017. We report the observed hospital costs for different resource categories and the lifetime costs per patient, adjusted for censoring using Lin's method. The relationship between patients' characteristics and costs was studied using multivariable regression.

RESULTS

The average (SE) lifetime hospital costs of patients with advanced breast cancer were €52 709 (405). Costs differed considerably between patient subgroups, ranging from €29 803 for patients with a triple-negative subtype to €92 272 for patients with hormone receptor positive and human epidermal growth factor receptor 2 positive cancer. Apart from the cancer subtype, several other factors, including age and survival time, were independently associated with patient lifetime costs. Overall, a large share of costs was attributed to systemic therapies (56%), predominantly to a few expensive agents, such as trastuzumab (15%), everolimus (10%), and bevacizumab (9%), as well as to inpatient hospital days (20%).

CONCLUSIONS

This real-world study shows the high degree of variability in hospital resource use and associated costs in advanced breast cancer care. The presented resource use and costs data provide researchers and policy makers with key figures for economic evaluations and budget impact analyses.

Efficacy of Margetuximab vs Trastuzumab in Patients With Pretreated ERBB2-Positive Advanced Breast Cancer: A Phase 3 Randomized Clinical Trial

Question

Does margetuximab plus chemotherapy prolong progression-free survival and/or overall survival of patients with pretreated ERBB2-positive advanced breast cancer, relative to trastuzumab plus chemotherapy?

Findings

In the SOPHIA phase 3 randomized clinical trial of 536 patients with pretreated ERBB2-positive advanced breast cancer, margetuximab plus chemotherapy generated a statistically significant 24% relative risk reduction in the hazard of progression vs trastuzumab plus chemotherapy. After the second planned interim analysis of 270 deaths, median OS was 21.6 months with margetuximab vs 19.8 months with trastuzumab, and final analysis of OS will be reported subsequently.

Meaning

This trial demonstrates a head-to-head advantage of margetuximab (an Fc-engineered ERBB2-targeted antibody) compared with trastuzumab in a pretreated ERBB2-positive advanced breast cancer population.

Importance

ERRB2 (formerly HER2)–positive advanced breast cancer (ABC) remains typically incurable with optimal treatment undefined in later lines of therapy. The chimeric antibody margetuximab shares ERBB2 specificity with trastuzumab but incorporates an engineered Fc region to increase immune activation.

Objective

To compare the clinical efficacy of margetuximab vs trastuzumab, each with chemotherapy, in patients with pretreated ERBB2-positive ABC.

Design, Setting, and Participants

The SOPHIA phase 3 randomized open-label trial of margetuximab plus chemotherapy vs trastuzumab plus chemotherapy enrolled 536 patients from August 26, 2015, to October 10, 2018, at 166 sites in 17 countries. Eligible patients had disease progression on 2 or more prior anti-ERBB2 therapies and 1 to 3 lines of therapy for metastatic disease. Data were analyzed from February 2019 to October 2019.

Interventions

Investigators selected chemotherapy before 1:1 randomization to margetuximab, 15 mg/kg, or trastuzumab, 6 mg/kg (loading dose, 8 mg/kg), each in 3-week cycles. Stratification factors were metastatic sites (≤2, >2), lines of therapy (≤2, >2), and chemotherapy choice.

Main Outcomes and Measures

Sequential primary end points were progression-free survival (PFS) by central blinded analysis and overall survival (OS). All α was allocated to PFS, followed by OS. Secondary end points were investigator-assessed PFS and objective response rate by central blinded analysis.

Results

A total of 536 patients were randomized to receive margetuximab (n = 266) or trastuzumab (n = 270). The median age was 56 (27-86) years; 266 (100%) women were in the margetuximab group, while 267 (98.9%) women were in the trastuzumab group. Groups were balanced. All but 1 patient had received prior pertuzumab, and 489 (91.2%) had received prior ado-trastuzumab emtansine. Margetuximab improved primary PFS over trastuzumab with 24% relative risk reduction (hazard ratio [HR], 0.76; 95% CI, 0.59-0.98; P = .03; median, 5.8 [95% CI, 5.5-7.0] months vs 4.9 [95% CI, 4.2-5.6] months; October 10, 2018). After the second planned interim analysis of 270 deaths, median OS was 21.6 months with margetuximab vs 19.8 months with trastuzumab (HR, 0.89; 95% CI, 0.69-1.13; P = .33; September 10, 2019), and investigator-assessed PFS showed 29% relative risk reduction favoring margetuximab (HR, 0.71; 95% CI, 0.58-0.86; P < .001; median, 5.7 vs 4.4 months; September 10, 2019). Margetuximab improved objective response rate over trastuzumab: 22% vs 16% (P = .06; October 10, 2018), and 25% vs 14% (P < .001; September 10, 2019). Incidence of infusion-related reactions, mostly in cycle 1, was higher with margetuximab (35 [13.3%] vs 9 [3.4%]); otherwise, safety was comparable.

Conclusions and Relevance

In this phase 3 randomized clinical trial, margetuximab plus chemotherapy had acceptable safety and a statistically significant improvement in PFS compared with trastuzumab plus chemotherapy in ERBB2-positive ABC after progression on 2 or more prior anti-ERBB2 therapies. Final OS analysis is expected in 2021.

Trial Registration

ClinicalTrials.gov Identifier: NCT02492711

Survival before and after the introduction of pertuzumab and T-DM1 in HER2-positive advanced breast cancer, a study of the SONABRE Registry

Purpose

Immediate and proper implementation of a new and more potent therapy is important to ensure that the patient achieves the best possible outcome. This study aimed to examine whether the real-world overall survival (OS) has improved in patients with human epidermal growth factor receptor 2-positive (HER2 +) advanced breast cancer (ABC) since the market release of pertuzumab and T-DM1. Furthermore, we aimed to assess the implementation and survival rates per hormone receptor (HR) subtype.

Patients and methods

We included 493 systemically treated patients consecutively diagnosed with HER2 + ABC in 2008–2017 from the SOutheast Netherlands Advanced BREast cancer (SONABRE) Registry. Median OS was obtained using the Kaplan–Meier method and differences between periods (2008–2012 versus 2013–2017) were tested using multivariable Cox proportional hazards regression modeling. The 3-year implementation rates were estimated for any HER2-targeted therapy, pertuzumab, and T-DM1 by using the competing risk method and calculated from the date of diagnosis of ABC to start of HER2-targeted therapy of interest.

Results

The median OS in 2008–2012 versus 2013–2017 was 28.3 versus 39.7 months in all patients (adjusted hazard ratio (adjHR) 0.85, 95%CI 0.66–1.08), 29.9 versus 36.3 months in patients with HR + /HER2 + disease (adjHR 0.97, 95%CI 0.72–1.32), and 22.7 versus 40.9 months in patients with HR-/HER2 + disease (adjHR 0.59, 95%CI 0.38–0.92). Any HER2-targeted therapy was used in 79% of patients in 2008–2012 and in 84% in 2013–2017. The use of pertuzumab and T-DM1 in 2013–2017 was 48% and 29%, respectively. For patients diagnosed with HR + /HER2 + and HR-/HER2 + disease, implementation rates in 2013–2017 were , respectively, 77% and 99% for any HER2-targeted therapy, 38% and 69% for pertuzumab, and 24% and 40% for T-DM1.

Conclusion

The survival of patients with HER2 + ABC improved since the introduction of pertuzumab and T-DM1. There is room for improvement in implementation of these HER2-targeted therapies, especially in patients with HR + /HER2 + disease.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-021-06178-8.

Abstract PS10-12: Integrated safety summary of single agent and combination margetuximab in phase 1, 2, and 3 studies of HER2-positive advanced cancers and metastatic breast cancer (MBC)

Background Margetuximab (M) is an investigational Fc-engineered anti-HER2 monoclonal antibody that targets the same epitope as trastuzumab (T). Compared with T, M has higher affinity for both the 158V (high-binding) and 158F (low-binding) allotypes of the activating Fc receptor CD16A. M enhances innate immunity more effectively than T in vitro, including CD16A-mediated antibody-dependent cellular cytotoxicity. Samples collected from patients (pts) before and after single-agent treatment also demonstrate that M induces HER2-specific adaptive immune responses, including both T- and B-cell responses. The SOPHIA trial (NCT02492711) in pts with pretreated HER2+ MBC showed that M+chemotherapy (chemo) improved progression-free survival vs T+chemo, with comparable safety. A pooled analysis of M safety across 3 clinical trials is presented. Methods Study 01 (NCT01148849), an ongoing Phase 1 dose-finding/safety study of M monotherapy, enrolled 66 pts with advanced HER2+ carcinomas, including 27 with MBC. Study 02 (NCT01828021), a completed Phase 2 study of M monotherapy in low-expressing HER2+ MBC, enrolled 25 pts. Study 04 (NCT02492711), an ongoing Phase 3 study in pts with pretreated HER2+ MBC to compare M + chemo vs T + chemo, randomized 536 pts, of whom 264 and 265 received M and T, respectively. The pooled safety population includes all pts who received any M in Study 01 (cutoff 01Oct2015), Study 02 (cutoff 02Aug2017), and Study 04 (cutoff 10OCT2018). Treatment-emergent adverse events (AEs), defined as AEs that began or worsened in severity on or after first dose of study drug through an End of Treatment Visit or 28 days after last study treatment, are reported. Results Of 355 pts that received at least 1 dose of M, 295 received 15 mg/kg Q3W, and 60 received other doses from 0.1 - 18 mg/kg. Median (mean, range) number of cycles for all dose levels was 5.0 (6.6, 1-43), higher on Study 04 (6.0) than Study 01 (1-3 across dose groups) or Study 02 (2.0). Most pts (347 [97.7%]) experienced at least 1 AE, and about half (173 [48.7%]) had at least 1 Grade &gt;/= 3 AE. Serious AE (SAE) incidence across studies was low (58 [16.3%]), and 21 pts (5.9%) discontinued M due to AEs. Most frequently reported AEs (&gt;/= 20%) were fatigue (124 [34.9]), nausea (103 [29.0%]), diarrhea (75 [21.1%]), and neutropenia (75 [21.1%]). Blood/lymphatic system disorders were the most frequent events by SOC, and largely restricted to Study 04. Increased neutropenia on M (26.1%), relative to T (20.4%), was observed in Study 04 yet both febrile neutropenia (M 3.0%, T 4.5%) and infections (M 36.4%, T 39.6%) were higher on T. By contrast, Study 01 and Study 02 revealed no tendency of M monotherapy to cause neutropenia. Overall, infusion related reactions (IRRs) were observed in 51 pts (14.4%), primarly at first infusion, including serious IRRs in 5 (1.4%). Also, 34 pts (9.6%) had &gt; 15% reduction in LVEF with a median time to &gt; 15% reduction of 49 days. In all pts with complete follow-up, these LVEF reductions were asymptomatic and reversible. No M-induced cardiac conduction abnormalities were noted. In Study 04, similar proportions in both groups experienced AEs (M 97.7%, T 96.2%), including Grade &gt;/= 3 AEs (M 52.3%, T 48.3%), SAEs (M 14.8%, T 17.4%), discontinuations due to AEs (M 3.0%, T 2.6%), and deaths due to AEs (M 0.8%, T 0.8%). As of the 23Feb2020 safety update, 2 pts remain on M in Study 01, after 116 and 109 cycles (6.7 and 6.3 years), respectively. In Study 04, 16 pts (6%) continued on M, and 7 (2.6%) remained on T. Discussion M has demonstrated an acceptable safety profile across Phase 1, 2, and 3 studies. It has been administered for over 6 years without long-term cumulative safety issues. Combined M plus chemotherapy Q3W demonstrated acceptable safety and tolerability, similar to that for T plus chemotherapy Q3W in Study 04.

Citation Format: Seock-Ah Im, Fatima Cardoso, Javier Cortes, Giuseppe Curigliano, Mark D. Pegram, Hope S. Rugo, Ursa Brown-Glaberman, Denise A. Yardley, Sung-Bae Kim, Maaike de Boer, Zbigniew Nowecki, Vesna Glavicic, Ido Wolf, Nele Claes, Joo Hyuk Sohn, Thomas Bachelot, Peter A. Kaufman, Jan Baughman, Shengyan Hong, Kenneth Jacobs, Edwin Rock, William J. Gradishar. Integrated safety summary of single agent and combination margetuximab in phase 1, 2, and 3 studies of HER2-positive advanced cancers and metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS10-12.

An economic evaluation of eribulin for advanced breast cancer treatment based on the Southeast Netherlands advanced breast cancer registry

Background: In 2013, eribulin was reimbursed under a coverage with evidence development (CED) as third or later chemotherapy line for advanced breast cancer (ABC) patients in the Netherlands because of uncertain cost effectiveness. In 2016, the final decision of reimbursing eribulin was taken without considering the evidence collected during CED research. We analysed the cost effectiveness of eribulin versus non-eribulin chemotherapy, using real-world data.Methods: A three health states (progression-free, progressed disease, dead) partitioned survival model was developed. The SOuth East Netherlands Advanced BREast Cancer (SONABRE) registry informed the effectiveness and costs inputs. Health state utility values were obtained from the literature. Incremental cost-effectiveness ratio (ICER) between the eribulin and matched non-eribulin chemotherapy was estimated. Deterministic and probabilistic sensitivity analyses and scenario analyses were performed. The financial risk (i.e., the expected value of perfect information (EVPI) plus the expected monetary loss (eML) associated with reimbursing eribulin) and budget impact associated with reimbursing eribulin were calculated.Results: Eribulin led to higher health benefits (0.07 quality-adjusted life year (QALY)) and costs (€15,321) compared with non-eribulin chemotherapy. This resulted in an ICER of €220,608. At a €80,000 per QALY threshold, the risk of reimbursing eribulin was €9,791 per patient (EVPI €13, eML €9,778). Scaled up to the Dutch population, the estimated annual budget impact was €1.9 million and the annual risk of reimbursing eribulin was €2.7 million.Conclusion: From a Dutch societal perspective, eribulin is not cost effective when considering its list price as third and later chemotherapy line for ABC patients.

Prospective Study of Drug-induced Interstitial Lung Disease in Advanced Breast Cancer Patients Receiving Everolimus Plus Exemestane

BACKGROUND

Everolimus-related interstitial lung disease (ILD) (also: pneumonitis) poses a difficulty for physicians, as it is hard to discriminate ILD from other causes of respiratory symptoms and to decide on safe treatment continuation.

OBJECTIVE

We investigated the capability of pulmonary function tests (PFT), plasma biomarkers, everolimus pharmacokinetics, and FDG-PET to discriminate between everolimus-related ILD and other causes of respiratory problems and to predict the severity of ILD.

PATIENTS AND METHODS

Women starting treatment with everolimus plus exemestane for advanced breast cancer were included. At baseline and during the first 3 months, respiratory symptoms, PFT with diffusion capacity of the lungs for carbon monoxide corrected for hemoglobin (DLCOc) and forced vital capacity, serum plasma biomarkers (including SP-D and YKL-40), everolimus trough concentration, and ¹⁸F-FDG-PET were prospectively recorded.

RESULTS

Twenty-seven (out of 29 included) patients were evaluable for analysis. Fifteen patients (56%) developed everolimus-related respiratory signs or symptoms and four patients (15%) needed everolimus discontinuation and received corticosteroids. Change in DLCOc differentiated ILD from alternative diagnoses with 0.91 sensitivity and 0.78 specificity. Decrease in DLCOc (non-significant) was greatest in patients who needed everolimus discontinuation. Serum SP-D and YKL-40 could differentiate ILD from alternative diagnoses with 0.83 and 0.83 sensitivity, and 0.85 and 0.62 specificity, respectively. ¹⁸F-FDG-PET abnormalities did not precede clinical symptoms. No relationship between ILD and everolimus trough concentration was found.

CONCLUSIONS

This study shows that everolimus-related ILD occurs frequently. Prospective monitoring of DLCOc in combination with measurement of serum SP-D and YKL-40 appear useful to discriminate ILD from other causes of respiratory symptoms. Clinicaltrials.gov identifier: NCT01978171.

Preserving fertility in young women undergoing chemotherapy for early breast cancer; the Maastricht experience

Purpose

We assessed the uptake of fertility preservation (FP), recovery of ovarian function (OFR) after chemotherapy, live birth after breast cancer, and breast cancer outcomes in women with early-stage breast cancer.

Methods

Women aged below 41 years and referred to our center for FP counseling between 2008 and 2015 were included. Data on patient and tumor characteristics, ovarian function, cryopreservation (embryo/oocyte) and transfer, live birth, and disease-free survival were collected. Kaplan–Meier analyses were performed for time-to-event analyses including competing risk analyses, and patients with versus without FP were compared using the logrank test.

Results

Of 118 counseled women with a median age of 31 years (range 19–40), 34 (29%) chose FP. Women who chose FP had less often children, more often a male partner and more often favorable tumor characteristics. The 5-year OFR rate was 92% for the total group of counseled patients. In total, 26 women gave birth. The 5-year live birth rate was 27% for the total group of counseled patients. Only three women applied for transfer of their cryopreserved embryo(s), in two combined with preimplantation genetic diagnosis (PGD) because of BRCA1-mutation carrier ship. The 5-year disease-free survival rate was 91% versus 88%, for patients with versus without FP (P = 0.42).

Conclusions

Remarkably, most women achieved OFR, probably related to the young age at diagnosis. Most pregnancies occurred spontaneously, two of three women applied for embryo transfer because of the opportunity to apply for PGD.

Breast cancer outcome in relation to bone mineral density and bisphosphonate use: a sub-study of the DATA trial

Purpose

The phase III DATA study compared 6 and 3 years of adjuvant anastrozole following 2–3 years of tamoxifen in postmenopausal breast cancer patients. This pre-planned side-study assessed the relationship between a reduced bone mineral density (BMD) and distant recurrence-free survival (DRFS), and evaluated the effect of bisphosphonates on DRFS.

Methods

We selected all patients with a BMD measurement within 3 years after randomisation (landmark) without any DRFS events. Kaplan–Meier methods and Cox proportional hazards models were used for analyses.

Results

Of 1860 eligible patients, 1142 had a DEXA scan before the landmark. The BMD was normal in 436 (38.2%) and showed osteopenia in 565 (49.5%) and osteoporosis in 141 (12.3%) patients. After a median follow-up of 5.0 years from the landmark, neither osteopenia nor osteoporosis (compared with normal BMD) were associated with DRFS in both the 6-year [osteopenia HR 0.82 (95% CI 0.45–1.49), osteoporosis HR 1.10 (95% CI 0.26–4.67)] and the 3-year arm [osteopenia HR 0.75 (95% CI 0.40–1.42), osteoporosis HR 1.86 (95% CI 0.43–8.01)]. Moreover, bisphosphonate use did not impact DRFS.

Conclusion

No association was observed between a reduced BMD and DRFS. Neither did we observe an impact of bisphosphonates on DRFS.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05567-9) contains supplementary material, which is available to authorized users.

Abstract P2-08-06: Initial systemic treatment choices by subtype of advanced breast cancer in 2007-2017, a study of the southeast Netherlands advanced breast cancer (SONABRE) registry

Background The aim of this study was to determine the subtype conversion rate and the initial systemic treatment choices by subtype for patients diagnosed with advanced breast cancer since 2007 who were included in the SONABRE Registry. Patients and methods Patients diagnosed with advanced breast cancer in 2007-2017 in six (one academic, three teaching, two non-teaching) hospitals in the Netherlands were selected from the ongoing SOutheast Netherlands Advanced BREast Cancer (SONABRE) Registry (NCT-03577197). We registered patient, primary tumor, recurrent and metastatic disease characteristics, and (neo-)adjuvant and palliative treatment choices. Follow-up was collected until September 2018. To determine the subtype, we assessed the hormone receptor (HR) and the human epidermal growth factor receptor (HER)-2 status from the initial metastatic site(s). If not available, biopsy results from the locoregional recurrence or the primary breast cancer were used. Initial systemic treatment choices were presented by subtype (HR+/HER2-, HER2+, and triple negative (TN) disease). In this abstract, we present the findings for the period 2007-2017, at the SABCS 2019, we will present the results for the period 2007-2018. Results Of the 2288 patients included, 67% had HR+/HER2-, 16% HER2+, 15% TN disease and 2% of patients had unknown subtype. The HR and HER2 status were based on pathology of the metastasis in 48% and 40% of patients, respectively. In 41% and 25% of patients, the HR and HER2 status was determined for both the primary tumor and the initial metastatic sites. Of these latter patients, HR status changed from HR+ to HR- in 10% of patients and from HR- to HR+ in 2% of patients. HER2 status changed from HER2+ to HER2- in 6% of patients and from HER2- to HER2+ in 4% of patients. Among patients with HR+/HER2- disease, 78% received endocrine-based and 17% received chemotherapy-based therapy as initial systemic therapy, and 5% of patients deceased without receiving any systemic therapy. For patients with HER2+ disease, 57% received HER2-targeted based therapy as initial systemic treatment, 22% received endocrine monotherapy, 8% received chemotherapy alone and 13% deceased without receiving systemic therapy. In patients with TN disease, 71% received chemotherapy as initial systemic treatment, 4% received endocrine therapy and 25% received no systemic therapy. Overall, 6% of patients received initial systemic therapy as part of a clinical trial. Conclusions For only half of the patients, HR and HER2 receptor status of the metastasis were determined at initiation of initial systemic therapy. Since one in ten tested patients showed a conversion of subtype, and thus impacting treatment decisions, it is important to reassess subtype upon diagnosis of metastatic disease whenever possible. With a few exceptions, initial systemic treatment choices were in line with guideline recommendations. Only 6% of patients were treated as part of a clinical trial, confirming the highly selected patient population included in these trials, highlighting the importance of real life studies to evaluate the outcomes of systemic treatment for advanced breast cancer.

Citation Format: Sandra M.E. Geurts, Khava IE Ibragimova, Frans Erdkamp, Birgit EPJ Vriens, M. Wouter Dercksen, Marien O den Boer, Manon JAE Pepels, Dominique Tilli, Maaike de Boer, Vivianne CG Tjan-Heijnen. Initial systemic treatment choices by subtype of advanced breast cancer in 2007-2017, a study of the southeast Netherlands advanced breast cancer (SONABRE) registry [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-08-06.

Assessment and management of bone health in women with early breast cancer receiving endocrine treatment in the DATA study

The phase III DATA study investigates the efficacy of adjuvant anastrozole (6 vs. 3 year) in postmenopausal women with breast cancer previously treated with 2–3 years of tamoxifen. This planned side‐study assessed patterns of care regarding detection and treatment of osteopenia/osteoporosis, and trends in bone mineral density (BMD) during and after therapy. We registered all BMD measurements and bisphosphonate‐use. Time to osteopenia/osteoporosis was analysed by Kaplan Meier methodology. For the trend in T‐scores we used linear mixed models with random patients effects. Of 1860 eligible DATA patients, 910 (48.9%) had a baseline BMD measurement. Among patients with a normal baseline BMD (n = 417), osteopenia was observed in 53.5% and 55.4% in the 6‐ and 3‐year group respectively (p = 0.18), during follow‐up. Only two patients (3‐year group) developed osteoporosis. Of the patients with osteopenia at baseline (n = 408), 24.4% and 20.4% developed osteoporosis respectively (p = 0.89). Three years after randomisation 18.3% and 18.2% used bisphosphonates in the 6‐ and 3‐year groups respectively and 6 years after randomisation this was 23.7% and 20.9% respectively (p = 0.90) of which the majority used oral bisphosphonates. The yearly mean BMD‐change during anastrozole in the lumbar spine showed a T‐score decline of 0.075. After bisphosphonate addition the decline became less prominent (0.047 (p < 0.001)) and after anastrozole cessation, while continuing bisphosphonates, the mean BMD yearly increased (0.047 (p < 0.001)). In conclusion, extended anastrozole therapy was not associated with a higher incidence of osteoporosis. Anastrozole‐use was associated with a BMD decrease; however, the decline was modest and partially reversible after anastrozole cessation.

What's new?

Loss of bone mineral density (BMD) is a side effect of aromatase inhibitor treatment, a class of drugs that stops estrogen production in postmenopausal women with breast cancer. Here the authors examined BMD loss during and after extended adjuvant endocrine therapy, following a 2‐3 year treatment with tamoxifen, subsequent aromatase inhibitor treatment was associated with BMD decrease, but the decline was modest and partially reversible after treatment cessation. The authors concluded that extended endocrine therapy was not associated with a higher incidence of osteoporosis.

Ovarian Function Recovery During Anastrozole in Breast Cancer Patients With Chemotherapy-Induced Ovarian Function Failure

Background

Aromatase inhibitors (AIs) are given as adjuvant therapy for hormone receptor-positive breast cancer in postmenopausal women, also to those with chemotherapy-induced ovarian function failure. The current analysis reports on endocrine data of patients with chemotherapy-induced ovarian function failure who were included in the phase III DATA study assessing different durations of adjuvant anastrozole after tamoxifen.

Methods

We identified all patients with chemotherapy-induced ovarian function failure. Women who underwent a bilateral ovariectomy or used luteinizing hormone-releasing hormone agonists before random assignment were excluded. Plasma estradiol and follicle-stimulating hormone levels were monitored until 30 months after random assignment at local laboratories. We aimed to determine the ovarian function recovery (OFR) rate during AI use by the cumulative incidence competing risk method and analyzed the trend of estradiol levels during AI use by a nested case-control approach in which a subset of control subjects were compared with the OFR patients excluding the value at OFR diagnosis.

Results

The 329 eligible patients had a median age of 50.0 years (range = 45-57 years) at random assignment. Thirty-nine patients developed OFR, corresponding with a 30-month recovery rate of 12.4%. Of these, 11 (28.2%) were age 50 years or older at AI initiation. The estradiol level decreased statistically significantly by 37.8% (95% CI = 27.4% to 46.7%) over the initial 30 months of AI treatment in both groups. However, the estradiol levels in the women who experienced OFR remained statistically significantly higher (difference = 20.6%, 95% CI = 2.0% to 42.7%) prior to OFR diagnosis compared with those who did not experience OFR.

Conclusions

The risk of OFR during AI treatment in breast cancer patients with chemotherapy-induced ovarian function failure is relevant, even beyond 45 years. Furthermore, women experiencing OFR had statistically significant higher estradiol levels during AI treatment (before OFR) than those without, with potential consequences regarding efficacy.

Efficacy of anastrozole after tamoxifen in early breast cancer patients with chemotherapy-induced ovarian function failure

The DATA study (NCT00301457) compared 6 and 3 years of anastrozole in postmenopausal women with hormone receptor-positive early breast cancer after 2-3 years of tamoxifen. Patients with chemotherapy-induced ovarian function failure (CIOFF) were also eligible, but could be at risk of ovarian function recovery (OFR). The current analysis compared the survival of women with CIOFF with definitely postmenopausal women and examined the influence of OFR on survival. Therefore, we selected patients from the DATA study aged 45-57 years at randomization who had received (neo)adjuvant chemotherapy. They were classified by reversibility of postmenopausal status: possibly reversible in case of CIOFF (n = 395) versus definitely postmenopausal (n = 261). The former were monitored by E2 measurements for OFR. The occurrence of OFR was incorporated as a time-dependent covariate in a Cox-regression model for calculating the hazard ratio (HR). We used the landmark method to calculate residual 5-year survival rates. When comparing CIOFF women with definitely postmenopausal women, the survival was not different. Among CIOFF women with available E2 follow-up values (n = 329), experiencing OFR (n = 39) had an unfavorable impact on distant recurrence-free survival (HR 2.27 [95% confidence interval [CI] 0.98-5.25; p = 0.05] and overall survival (HR 2.61 [95% CI 1.11-6.13; p = 0.03]). After adjusting for tumor features, the HRs became 2.11 (95% CI 0.89-5.02; p = 0.09) and 2.24 (95% CI 0.92-5.45; p = 0.07), respectively. The residual 5-year rate for distant recurrence-free survival was 76.9% for women with OFR and 92.1% for women without OFR, and for 5-year overall survival 80.8% and 94.4%, respectively. Women with CIOFF receiving anastrozole may be at increased risk of disease recurrence if experiencing OFR.

Axillary staging in breast cancer patients treated with neoadjuvant chemotherapy in two Dutch phase III studies

BACKGROUND

Primary aim of our study was to assess the impact of timing of sentinel node procedure, pre- versus post-neoadjuvant chemotherapy, on final pathologic node-negative rate (pN0) in patients with clinically node-negative (cN0) breast cancer. Secondary endpoint was the usability of the sentinel node procedure in patients with clinically node-positive disease that converted to cN0 after neoadjuvant chemotherapy.

PATIENTS AND METHODS

Patients were enrolled in two sequentially conducted Dutch phase III trials, studying the impact of two neoadjuvant chemotherapy schedules and use of zoledronic acid on complete pathologic response rate. For the present analyses, patients were excluded if they had not undergone surgical axillary staging.

RESULTS

In total 439 patients were included, of whom 230 (52%) had pre-treatment cN0. In this group, pN0 status was seen in 58% (N = 23) of patients with a sentinel node biopsy post-neoadjuvant chemotherapy compared to 51% (N = 83) pre-neoadjuvant chemotherapy, including the axillary lymph node dissection whenever performed. In multivariable analysis, timing of sentinel node procedure (pre- versus post- neoadjuvant chemotherapy) was, however, not significantly associated with final pN0/pN0(i+) status, with an odds ratio of 1.18 (95% CI 0.64 - 2.18) after correction for age, clinical tumor status, histology, grade, hormone- and HER2 receptor. Of patients with clinically node-positive disease only 15% had a final pN0 status, with a false-negative rate of the sentinel node of 30%.

CONCLUSION

In breast cancer patients with cN0 disease, sentinel node procedure performed post-neoadjuvant chemotherapy led to nodal down staging, although not statistically significant after multivariate correction for patient and tumor characteristics.

The correlation of age with chemotherapy-induced ovarian function failure in breast cancer patients

PURPOSE

To assess the incidence of chemotherapy-induced ovarian function failure (COFF) based on estradiol and follicle stimulating hormone (FSH) monitoring in premenopausal women with hormone-receptor positive breast cancer treated with second and third generation (neo-)adjuvant chemotherapy.

RESULTS

We identified 115 eligible women. Two years after start of chemotherapy, COFF was significantly more often present in women ≥ 40 years (85.6%) as compared to women < 40 years (8.7%). Only age was significantly associated with COFF two years after start of chemotherapy (HR 12.26; 95% CI 5.21-28.86). In 50% of the patients, premenopausal hormone levels were the first or only evidence of ovarian function recovery (OFR).

MATERIALS AND METHODS

We included all premenopausal women with hormone-receptor positive breast cancer treated with anthracycline-based chemotherapy, with or without taxanes, in our university hospital in the Netherlands in the years 2005-2013. Patients were 3-monthly monitored for ovarian function. Cox proportional hazards model was used to determine the predictive impact of various parameters on the occurrence of COFF.

CONCLUSIONS

After second- or third generation (neo-)adjuvant chemotherapy, COFF was still present in 8.7% of patients < 40 years after two years. FSH and estradiol monitoring may be relevant for those in whom ovarian function suppression is considered an additional effective endocrine treatment.

Neutrophil Recovery in Breast Cancer Patients Receiving Docetaxel-Containing Chemotherapy with and without Granulocyte Colony-Stimulating Factor Prophylaxis

OBJECTIVE

The primary outcome of the current study is, whether there is a protective effect of prior chemotherapy or of prior granulocyte colony-stimulating factor (G-CSF) on the next cycle blood cell counts.

METHODS

Hematologic toxicity was evaluated, based on a randomized phase III study in breast cancer patients (n = 167) with >20% risk of febrile neutropenia. The primary endpoint was the nadir blood cell counts for patients treated with G-CSF given during all 6 chemotherapy cycles or limited to the first 2 chemotherapy cycles only.

RESULTS

For the present analyses, 47 patients were eligible. In the G-CSF 1-6 arm, the median white blood cell count (WBC) and absolute neutrophil count (ANC) nadir slowly decreased from 10.8 × 109/L in cycle 1 to 7.5 × 109/L in cycle 6 and from 7.1 × 109/L to 5.5 × 109/L, respectively. The median WBC nadir in the G-CSF 1-2 arm decreased from 1.2 × 109/L in cycle 3 to 0.9 × 109/L in cycle 6 and the ANC nadir showed a grade 4 neutropenia of 0.1 × 109/L in cycles 3-6. All patients had ANC recovery to normal levels (≥1.5 × 109/L) without delay on day 1 of the next cycle.

CONCLUSION

We conclude that there is no protective effect of prior G-CSF or prior chemotherapy use on nadir blood cell counts in subsequent cycles.

Clinical tumor stage is the most important predictor of pathological complete response rate after neoadjuvant chemotherapy in breast cancer patients

BACKGROUND

Pathological complete response (pCR) is the ultimate response in breast cancer patients treated with neoadjuvant chemotherapy (NCT). It might be a surrogate outcome for disease-free survival (DFS) and overall survival (OS). We studied the effect of clinical tumor stage (cT-stage) on tumor pCR and the effect of pCR per cT-stage on 5-year OS and DFS.

METHODS

Using the Netherlands Cancer Registry, all primary invasive breast cancer patients treated with NCT from 2005 until 2008 were identified. Univariable logistic regression analysis was performed to evaluate the effect of cT-stage on pCR, stepwise logistic regression analysis to correct for potential confounders and Kaplan-Meier survival analyses to calculate OS and DFS after five years.

RESULTS

In 2366 patients, overall pCR rate was 21%. For cT1, cT2, cT3, and cT4, pCR rates were 31, 22, 18, and 17%, respectively. Lower cT-stage (cT1-2 vs cT3-4) was a significant independent predictor of higher pCR rate (p < 0.001, OR 3.15). Furthermore, positive HER2 status (p < 0.001, OR 2.30), negative estrogen receptor status (p = 0.062, OR 1.69), and negative progesterone receptor status (p = 0.008, OR 2.27) were independent predictors of pCR. OS and DFS were up to 20% higher in patients with cT2-4 tumors with pCR versus patients without pCR. DFS was also higher for cT1 tumors with pCR.

CONCLUSIONS

The most important predictor of pCR in breast cancer patients is cT-stage: lower cT-stages have significantly higher pCR rates than higher cT-stages. Patients with cT2-4 tumors achieving pCR have higher OS and DFS compared to patients not achieving pCR.

Functional status decline in older patients with breast and colorectal cancer after cancer treatment: A prospective cohort study

OBJECTIVES

The aim of the present study was to disentangle the impact of age and that of cancer diagnosis and treatment on functional status (FS) decline in older patients with cancer.

MATERIALS AND METHODS

Patients with breast and colorectal cancer aged 50-69years and aged ≥70years who had undergone surgery, and older patients without cancer aged ≥70years were included. FS was assessed at baseline and after 12months follow-up, using the Katz index for activities of daily living (ADL) and the Lawton scale for instrumental activities of daily living (IADL). FS decline was defined as ≥1 point decrease on the ADL or IADL scale from baseline to 12months follow-up.

RESULTS

In total, 179 older patients with cancer (≥ 70years), 341 younger patients with cancer (50-69years) and 317 older patients without cancer (≥ 70years) were included. FS decline was found in 43.6%, 24.6% and 28.1% of the groups, respectively. FS decline was significantly worse in older compared to younger patients with cancer receiving no chemotherapy (44.5% versus 17.6%, p<0.001), but not for those who did receive chemotherapy (39.4% versus 30.8%, p=0.33). Among the patients with cancer, FS decline was significantly associated with older age (OR 2.63), female sex (OR 3.72), colorectal cancer (OR 2.81), polypharmacy (OR 2.10) and, inversely, with baseline ADL dependency (OR 0.44).

CONCLUSION

Cancer treatment, and older age are important predictors of FS decline. The relation of baseline ADL dependency and chemotherapy with FS decline suggest that the fittest of the older patients with cancer were selected for chemotherapy.

Risk of regional recurrence in triple-negative breast cancer patients: a Dutch cohort study

Triple-negative breast cancer is associated with early recurrence and low survival rates. Several trials investigate the safety of a more conservative approach of axillary treatment in clinically T1-2N0 breast cancer. Triple-negative breast cancer comprises only 15 % of newly diagnosed breast cancers, which might result in insufficient power for representative results for this subgroup. We aimed to provide a nationwide overview on the occurrence of (regional) recurrences in triple-negative breast cancer patients with a clinically T1-2N0 status. For this cohort study, 2548 women diagnosed between 2005 and 2008 with clinically T1-2N0 triple-negative breast cancer were selected from the Netherlands Cancer Registry. Follow-up data until 2014 were analyzed using Kaplan–Meier. Sentinel lymph node biopsy was performed in 2486 patients, and (completion) axillary lymph node dissection in 562 patients. Final pathologic nodal status was pN0 in 78.5 %, pN1mi in 4.5 %, pN1 in 12.3 %, pN2–3 in 3.6 %, and pNx in 1.1 %. During a follow-up of 5 years, regional recurrence occurred in 2.9 %, local recurrence in 4.2 % and distant recurrence in 12.2 %. Five-year disease-free survival was 78.7 %, distant disease-free survival 80.5 %, and 5-year overall survival 82.3 %. Triple-negative clinically T1-2N0 breast cancer patients rarely develop a regional recurrence. Their disease-free survival is more threatened by distant recurrence, affecting their overall survival. Consequently, it seems justified to include triple-negative breast cancer patients in randomized controlled trials investigating the safety of minimizing axillary staging and treatment.

Cardiotoxicity and Cardiac Monitoring During Adjuvant Trastuzumab in Daily Dutch Practice: A Study of the Southeast Netherlands Breast Cancer Consortium

INTRODUCTION

We assessed the incidence and timing of first cardiac events, impact on trastuzumab prescription, and role of left ventricular ejection fraction (LVEF) monitoring in daily practice of trastuzumab-treated patients with human epidermal growth receptor 2 (HER2)-positive early breast cancer.

METHODS

We included all patients with stage I-III breast cancer diagnosed in the early years (2005-2007) after the introduction of adjuvant trastuzumab in five hospitals in Southeast Netherlands. We studied the incidence and timing of cardiotoxicity in patients treated with adjuvant trastuzumab, using similar cardiac endpoints as in the Herceptin Adjuvant (HERA) trial.

RESULTS

Of 2,684 included patients, 476 (17.7%) had a HER2-positive tumor. Of these, 269 (56.9%) were treated with adjuvant chemotherapy, and of these, 230 (85.5%) also received trastuzumab. Cardiotoxicity was observed in 29 of 230 patients (12.6%). Twenty of the 230 patients (8.7%) had symptomatic cardiotoxicity, defined as a drop in LVEF of at least 10 percentage points and to below 50%, accompanied by symptoms of congestive heart failure. Trastuzumab was definitely discontinued because of supposed cardiotoxicity in 36 patients (15.6%), of whom only 15 (6.5%) had a significant LVEF drop. Of the 36 patients who prematurely discontinued trastuzumab (including the 29 in whom cardiotoxicity was observed), 84.8% stopped in the first 6 months. No cardiac deaths were seen.

CONCLUSION

In the first years after implementation of trastuzumab for treatment of early breast cancer, physicians frequently based their decision to discontinue treatment on patient symptoms apart from LVEF outcome. We suggest that focusing LVEF monitoring on the first 6 months might be more cost-effective without compromising patient safety. Nonetheless, further research is needed.

IMPLICATIONS FOR PRACTICE

Knowledge of when cardiotoxicity occurs in daily practice will help shape the best follow-up method for cardiac monitoring in trastuzumab-treated patients with human epidermal growth receptor 2-positive early breast cancer. In the first years after implementation of trastuzumab for treatment of early breast cancer, physicians frequently based their decision to discontinue treatment on patient symptoms apart from left ventricular ejection fraction (LVEF) outcome. When cardiotoxicity was found in daily practice, it occurred mainly in the first 6 months after start of trastuzumab. This study suggests that focusing LVEF monitoring on the first 6 months might be more cost-effective without compromising patient safety. This insight stresses the relevance of performing real-world analyses.

Ultrasound is at least as good as magnetic resonance imaging in predicting tumour size post-neoadjuvant chemotherapy in breast cancer

BACKGROUND

The aim of this study was to evaluate the accuracy of clinical imaging of the primary breast tumour post-neoadjuvant chemotherapy (NAC) related to the post-neoadjuvant histological tumour size (gold standard) and whether this varies with breast cancer subtype. In this study, results of both magnetic resonance imaging (MRI) and ultrasound (US) were reported.

METHODS

Patients with invasive breast cancer were enrolled in the INTENS study between 2006 and 2009. We included 182 patients, of whom data were available for post-NAC MRI (n=155), US (n=123), and histopathological tumour size.

RESULTS

MRI estimated residual tumour size with <10-mm discordance in 54% of patients, overestimated size in 28% and underestimated size in 18% of patients. With US, this was 63%, 20% and 17%, respectively. The negative predictive value in hormone receptor-positive tumours for both MRI and US was low, 26% and 33%, respectively. The median deviation in clinical tumour size as percentage of pathological tumour was 63% (P25=26, P75=100) and 49% (P25=22, P75=100) for MRI and US, respectively (P=0.06).

CONCLUSIONS

In this study, US was at least as good as breast MRI in providing information on residual tumour size post-neoadjuvant chemotherapy. However, both modalities suffered from a substantial percentage of over- and underestimation of tumour size and in addition both showed a low negative predictive value of pathologic complete remission (Gov nr: NCT00314977).

Real-Life Use and Effectiveness of Adjuvant Trastuzumab in Early Breast Cancer Patients: A Study of the Southeast Netherlands Breast Cancer Consortium

BACKGROUND

The impact of drug prescriptions in real life as opposed to strict clinical trial prescription is only rarely assessed, although it is well recognized that incorrect use may harm patients and may have a significant impact on health care resources. We investigated the use and effectiveness of adjuvant trastuzumab in daily practice compared with the effectiveness in clinical trials.

METHODS

We included all patients with stage I-III invasive breast cancer, irrespective of human epidermal growth factor receptor 2 (HER2) status, diagnosed in five hospitals in the southeast of The Netherlands in 2005-2007. We aimed to assess the actual use of adjuvant trastuzumab in early HER2-positive breast and its efficacy in daily practice.

RESULTS

Of 2,684 patients included, 476 (17.7%) had a HER2-positive tumor. Of these, 251 (52.7%) patients had an indication for trastuzumab treatment of which 196 (78.1%) patients actually received it. Of the 225 patients without an indication, 34 (15.1%) received trastuzumab. Five-year disease-free survival was 80.7% for (n = 230) patients treated with versus 68.2% for (n = 246) patients not treated with trastuzumab (p = .0023), and 5-year overall survival rates were 90.7% and 77.4%, respectively (p = .0002). The hazard ratio for disease recurrence was 0.63 (95% confidence interval, 0.37-1.06) for trastuzumab when adjusting for potential confounders.

CONCLUSION

This study shows that in real life, patients treated with trastuzumab in early-stage HER2-positive breast cancer had a 5-year disease-free and overall survival comparable to prior randomized trials. For informative decision making, real-life data are of additional value, providing insight on outcome of patients considered ineligible for treatment.

Abstract P5-21-08: One-tenth of patients younger than 40 years develop a permanent chemotherapy-induced ovarian function failure after receiving adjuvant anthracycline-based chemotherapy with or without taxanes

Background

To assess the incidence and predictors of (permanent) chemotherapy-induced ovarian function failure (COFF) in premenopausal women with hormone receptor positive breast cancer treated with adjuvant chemotherapy.

Patients and methods

In our university hospital, patients with COFF and hormone-receptor positive breast cancer are monitored for ovarian function recovery by 3-monthly FSH and estradiol blood levels (serum estradiol is measured by direct immunoassay). In this present study, we collected data from the medical records of all premenopausal women with hormone-receptor positive breast cancer treated with anthracycline-based chemotherapy, with or without the addition of taxanes, who were diagnosed in the years 2005-2012. To meet the definition of COFF, the amenorrhea and ovarian function suppression had to last ≥24 weeks since the last menstruation before or during chemotherapy. Patients with hormone-receptor negative breast cancer were excluded.

Results

We identified 135 eligible women. Initial oral hormonal therapy consisted of tamoxifen (n= 116) or aromatase inhibitors (AI, n=16, of whom 1 patient younger than 40 years). Median follow-up of the included patients was 25 months (range 3-69 months). The majority of women was older than 40 years (80%). Permanent or temporary COFF was present in 95.6% of patients; that is, in 97.2% of patients of ≥ 40 years versus in 88.8% of patients &lt; 40 years of age, which was not different between age-groups. However, permanent COFF was significantly more often present in women ≥ 40 years (75%) as compared with 11.1% of women &lt; 40 years ( P &lt; 0.03). Patients who developed a permanent COFF had a mean age of 47.4 (SD 3.9) years, whereas patients who developed a temporary COFF had a mean age of 38.0 (SD 6.5).

In 57% of the patients, premenopausal hormone levels were the first evidence of ovarian function recovery. The second-last FSH and estradiol values of patients who had an ovarian function recovery were still clearly in postmenopausal range (Figures will be shown at the meeting).

Conclusion

COFF is seen in 89% of patients &lt; 40 years, but in the majority it was reversible. This is reassuring for those with a childwish. As in a significant proportion of patients FSH and estradiol values are the first sign of ovarian function recovery, close monitoring of ovarian function is required if ovarian function suppression is considered an additional effective hormonal treatment, and with respect to indication of non-hormonal contraceptive devices. We would not recommend AI as single hormonal treatment in young patients with COFF.

Citation Format: Vivianne C Tjan-Heijnen, Ingeborg J Vriens, Ashley J Beijers, Maureen J Aarts, Maaike de Boer, Joyce H Royen, Ron J van Golde. One-tenth of patients younger than 40 years develop a permanent chemotherapy-induced ovarian function failure after receiving adjuvant anthracycline-based chemotherapy with or without taxanes [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-21-08.

Abstract P2-01-03: Sentinel node procedure before or after neoadjuvant chemotherapy in clinically node negative or positive patients; results from 3 phase III studies of the Dutch breast cancer trialists' group (BOOG)

Background

In breast cancer patients treated with neoadjuvant systemic therapy, the timing of the sentinel node (SN) procedure in patients with clinically node-negative disease (cN0) at diagnosis and the role of the SN procedure after neoadjuvant therapy in patients with initially clinical node-positive disease (cN+) still remains to be elucidated.

Methods

Between February 2006 and May 2012, 657 patients were enrolled in three clinical trials on neoadjuvant systemic therapy under the auspices of the Dutch Breast Cancer Research Group (BOOG). In the INTENS and NEO-ZOTAC study, patients were treated with TAC or AC-T neo-adjuvant chemotherapy (doxorubicin (A), cyclophosphamide (C) and docetaxel (T)). In the TEAM IIa trial, patients were treated with neoadjuvant endocrine therapy (exemestane for 6 months). Timing of the SN procedure in cN0 disease mainly depends on local policy and period of inclusion. We compared the pN0 rate after SN procedure performed before versus after neoadjuvant systemic therapy, in patients with cN0 disease at initial diagnosis. Further, we assessed the SN negative and the false-negative sentinel node rate in patients with initially cN+ breast cancer and conversion to cN0 when treated with neoadjuvant systemic therapy. The false-negative rate was obtained by dividing the number of patients who were SN-negative but non-SN positive by the number of patients who had a positive SN or a positive non-SN.

Results

In total, 271 patients (n=93 INTENS, n=107 NEOZOTAC, n= 71 TEAM IIa) underwent a SN procedure (n=233 cN0; n=38 cN+). Of patients with cN0 breast cancer at diagnosis, 131 (56%) underwent the SN procedure before and 102 (44%) after neoadjuvant systemic therapy, with ypN0(sn) or ypN0(i+)(sn) in 90/131 (69%) and 69/102 (68%) patients, respectively. Patients with initially cN+ disease who converted to cN0 disease after systemic therapy had a negative SN in 29% (11/38) of cases. The false-negative rate was 20% (6 of 30). More detailed analyses will be presented at the meeting.

Conclusion

To our knowledge, this is the first study comparing the impact of the timing of the sentinel procedure in patients with cN0 disease. We showed, that irrespective of the timing of the SN procedure - before or after neoadjuvant systemic therapy - in patients with cN0 breast cancer at diagnosis, two-third of patients had a negative sentinel node. In patients who converted after neoadjuvant chemotherapy from cN+ to cN0 the false negative sentinel node rate was 20%.

Citation Format: Vivianne C Tjan-Heijnen, Birgitte E Vriens, Maureen J Aarts, Judith R Kroep, Cock J van de Velde, Gerrit-Jan Liefers, Ayoub Charehbili, Petronella G Peer, Maaike de Boer. Sentinel node procedure before or after neoadjuvant chemotherapy in clinically node negative or positive patients; results from 3 phase III studies of the Dutch breast cancer trialists' group (BOOG) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-03.

[Combination of exemestane and everolimus may produce toxic side effects: a new treatment option for metastatic hormone-sensitive breast cancer]

The combination of exemestane and everolimus is a new treatment option for metastatic hormone-sensitive breast cancer. This treatment is used after progression on non-steroidal aromatase inhibitors. The treatment is generally well tolerated, but sometimes leads to minor or even serious side effects. It is important to be aware of these side effects and to treat them. We describe two patients who had to cope with various forms of toxicity: a 73-year-old woman with aphthous mouth lesions and a 49-year-old woman with pneumonitis. We then discuss the efficacy of the combination exemestane and everolimus and its positioning in the treatment of metastatic hormone-sensitive breast cancer. Finally, some common and some potentially serious side effects will be discussed, along with recommendations for their management and indications for distinguishing side effects from disease progression.

Prognosis of metastatic breast cancer subtypes: the hormone receptor/HER2-positive subtype is associated with the most favorable outcome

Contrary to the situation in early breast cancer, little is known about the prognostic relevance of the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) in metastatic breast cancer. The objectives of this study were to present survival estimates and to determine the prognostic impact of breast cancer subtypes based on HR and HER2 status in a recent cohort of metastatic breast cancer patients, which is representative of current clinical practice. Patients diagnosed with metastatic breast cancer between 2007 and 2009 were included. Information regarding patient and tumor characteristics and treatment was collected. Patients were categorized in four subtypes based on the HR and HER2 status of the primary tumor: HR positive (+)/HER2 negative (-), HR+/HER2+, HR-/HER2+ and triple negative (TN). Survival was estimated using the Kaplan-Meier method. Cox proportional hazards model was used to determine the prognostic impact of breast cancer subtype, adjusted for possible confounders. Median follow-up was 21.8 months for the 815 metastatic breast cancer patients included; 66 % of patients had the HR+/HER2- subtype, 8 % the HR-/HER2+ subtype, 15 % the TN subtype and 11 % the HR+/HER2+ subtype. The longest survival was observed for the HR+/HER2+ subtype (median 34.4 months), compared to 24.8 months for the HR+/HER2- subtype, 19.8 months for the HR-/HER2+ subtype and 8.8 months for the TN subtype (P < 0.0001). In the multivariate analysis, subtype was an independent prognostic factor, as were initial site of metastases and metastatic-free interval. The HR+/HER2+ subtype was associated with the longest survival after diagnosis of distant metastases.

Prognostic impact of isolated tumor cells and micrometastases in axillary lymph nodes of breast cancer patients

With the introduction of the sentinel node (SN) procedure, the detection frequency of nodal isolated tumor cells and micrometastases has increased. We reviewed the literature on prognostic significance of these small nodal metastases. All studies before the SN era and all studies using the SN procedure that reported outcome in relation to presence of isolated tumor cells and/or micrometastases were included. Studies before the SN era were divided in 'cohort' and 'occult metastases' studies. The SN studies were divided in single-centre studies and in one multicentre cohort study. In the pre-SN cohort studies, axillary lymph node metastases of 2 mm or less were associated with reduced overall survival with an adjusted pooled hazard ratio of 1.44 (95%CI 1.29-1.62). In the pre-SN occult metastases studies, occult nodal metastases were associated with a pooled relative risk of deaths after 5 years of 1.45 (95%CI 1.11-1.88). In single-centre SN studies, using multivariate analyses, the presence of micrometastases was associated with a hazard ratio for disease events of 1.43 to 1.89 as compared to node-negative disease. The largest SN study, including nearly 2000 patients with isolated tumor cells or micrometastases, reported an adjusted hazard ratio for disease-events of 1.50 (95%CI 1.15-1.94) and 1.56 (95%CI 1.15-2.13), respectively, in patients who had not received systemic therapy. We conclude that isolated tumor cells and micrometastases are associated with increased risk of disease-events of about 1.5 compared to node-negative disease. Therefore, we recommend to consider the use of adjuvant systemic therapy in these patients.

Minimal lymph node involvement and outcome of breast cancer. The results of the Dutch MIRROR study

Even when a breast cancer patient has only minimal lymph node involvement, additional therapy is needed. If women are not treated with adjuvant systemic therapy like chemotherapy and/or hormonal therapy, disease-free survival is reduced by 10% at 5-year follow-up. These are the main results from the MIRROR study, a Dutch cohort study in which all hospitals from The Netherlands have participated. The results were recently published in the New England Journal of Medicine (de Boer, 2009). The study was supported by a grant from the Netherlands Organization for Health Research and Development (945-06-509).

Micrometastases or isolated tumor cells and the outcome of breast cancer

BACKGROUND

The association of isolated tumor cells and micrometastases in regional lymph nodes with the clinical outcome of breast cancer is unclear.

METHODS

We identified all patients in The Netherlands who underwent a sentinel-node biopsy for breast cancer before 2006 and had breast cancer with favorable primary-tumor characteristics and isolated tumor cells or micrometastases in the regional lymph nodes. Patients with node-negative disease were randomly selected from the years 2000 and 2001. The primary end point was disease-free survival.

RESULTS

We identified 856 patients with node-negative disease who had not received systemic adjuvant therapy (the node-negative, no-adjuvant-therapy cohort), 856 patients with isolated tumor cells or micrometastases who had not received systemic adjuvant therapy (the node-positive, no-adjuvant-therapy cohort), and 995 patients with isolated tumor cells or micrometastases who had received such treatment (the node-positive, adjuvant-therapy cohort). The median follow-up was 5.1 years. The adjusted hazard ratio for disease events among patients with isolated tumor cells who did not receive systemic therapy, as compared with women with node-negative disease, was 1.50 (95% confidence interval [CI], 1.15 to 1.94); among patients with micrometastases, the adjusted hazard ratio was 1.56 (95% CI, 1.15 to 2.13). Among patients with isolated tumor cells or micrometastases, the adjusted hazard ratio was 0.57 (95% CI, 0.45 to 0.73) in the node-positive, adjuvant-therapy cohort, as compared with the node-positive, no-adjuvant-therapy cohort.

CONCLUSIONS

Isolated tumor cells or micrometastases in regional lymph nodes were associated with a reduced 5-year rate of disease-free survival among women with favorable early-stage breast cancer who did not receive adjuvant therapy. In patients with isolated tumor cells or micrometastases who received adjuvant therapy, disease-free survival was improved.

Non-sentinel lymph node metastases associated with isolated breast cancer cells in the sentinel node

There are many reports on the frequency of non-sentinel lymph node involvement when isolated tumor cells are found in the sentinel node, but results and recommendations for the use of an axillary lymph node dissection differ among studies. This systematic review was conducted to give an overview of this issue and to provide recommendations for the use of an axillary lymph node dissection in these patients. We searched Medline, Embase, and Cochrane databases from January 1, 2002, through November 27, 2007, for articles on patients with invasive breast cancer who had isolated tumor cells in the sentinel lymph node (according to the sixth edition of the Cancer Staging Manual of the American Joint Committee on Cancer) and who also underwent axillary lymph node dissection. Of 411 selected articles, 29 (including 836 patients) were included in this review. These 29 studies were heterogeneous, reporting a wide range of non-sentinel lymph node involvement (defined as the presence of isolated tumor cells or micro- or macrometastases) associated with isolated tumor cells in the sentinel lymph node, with an overall pooled risk for such involvement of 12.3% (95% confidence interval = 9.5% to 15.7%). This pooled risk estimate was marginally higher than the risk of a false-negative sentinel lymph node biopsy examination (ie, 7%-8%) but marginally lower than the risk of non-sentinel lymph node metastases in patients with micrometastases (ie, approximately 20%) who are currently eligible for an axillary lymph node dissection. Because 36 (64%) of the 56 patients with isolated tumor cells in their sentinel lymph node also had non-sentinel lymph node macrometastases, those patients with isolated tumor cells in the sentinel lymph node without other indications for adjuvant systemic therapy might be candidates for axillary lymph node dissection.