Stage I breast cancer in a regional oncology practice in Israel 2002-2006: clinicopathologic features, risk estimation and planned therapy of 328 consecutive patients

Stage I Breast Cancer in the Modern Era: A Retrospective Cohort Study of 328 Patients Diagnosed from 2002 to 2006 with a 14-Year Median Follow-Up

INTRODUCTION

This study aimed to evaluate the long-term outcomes of stage I breast cancer (BC) patients diagnosed during the current era of screening mammography, immunohistochemistry receptor testing, and systemic adjuvant therapy.

METHODS

A retrospective cohort study was conducted on 328 stage I BC patients treated consecutively in a single referral center with a follow-up period of at least 12 years. The primary endpoints were invasive disease-free survival (IDFS) and overall survival (OS). The influence of tumor size, grade, and subtype on the outcomes was analyzed.

RESULTS

Most patients were treated by lumpectomy, sentinel node biopsy, and adjuvant endocrine therapy, and most (82%) were of subtype luminal A. Adjuvant chemotherapy was administered to 25.6% of our cohort. Only 24 patients underwent gene expression testing, which was introduced toward the end of the study period. Mean IDFS was 14.64 years, with a 15-year IDFS of 75.6%. Mean OS was 15.28 years with a 15-year OS of 74.9%. In a Cox multivariate analysis, no clinical or pathologic variable impacted on OS and only tumor size (<1 cm vs. 1-2 cm) impacted significantly on IDFS. During follow-up, 20.1% of the cohort developed second primary cancers, including BC. The median time to diagnosis of a second BC was 6.49 years.

CONCLUSION

The study results emphasize the importance of long-term follow-up and screening for subsequent malignancies of patients with stage I BC and support the need for using prognostic and predictive indicators beyond the routine clinicopathological characteristics in luminal A patients.

GENE EXPRESSION PROFILING AND EXPANDED IMMUNOHISTOCHEMISTRY TESTS TO GUIDE SELECTION OF CHEMOTHERAPY REGIMENS IN BREAST CANCER MANAGEMENT: A SYSTEMATIC REVIEW

OBJECTIVES

The aim of this report was to assess the clinical effectiveness of two Gene expression profiling (GEP) and two expanded immunohistochemistry (IHC) tests compared with current prognostic tools in guiding the use of adjuvant chemotherapy in patients with early breast cancer.

METHODS

A systematic review of the evidence on clinical effectiveness of OncotypeDX, IHC4, MammaPrint, and Mammostrat, compared with current clinical practice using clinicopathological parameters, in women with early breast cancer was conducted. Ten databases were searched to include citations to May 2016.

RESULTS

Searches identified 7,064 citations, of which forty-one citations satisfied the criteria for the review. A narrative synthesis was performed. Evidence for OncotypeDX demonstrated the impact of the test on decision making and there was some support for OncotypeDX predicting chemotherapy benefit. There were relatively lower levels of evidence for the other three tests included in the analysis. MammaPrint, Mammostrat, and IHC4 tests were limited to a small number of studies. Limitations in relation to study design were identified for all tests.

CONCLUSIONS

The evidence base for OncotypeDX is considered to be the most robust. Methodological weaknesses relating to heterogeneity of patient cohorts and issues arising from the retrospective nature of the evidence were identified. Further evidence is required for all of the tests using prospective randomized controlled trial data.

The value of multigene predictors of clinical outcome in breast cancer: an analysis of the evidence

OBJECTIVE

Multigene predictors are being used increasingly in early-stage breast cancer patients for prediction and prognosis. However, one consequence of the increased use of multigene predictors, and the heightened efforts toward their incorporation into routine clinical practice, is the potential for future malpractice litigation. It is, therefore, important to ascertain the strength of the evidence for using the different commercially available multigene predictor assays clinically. We evaluated the literature for evidence of clinical validity of four currently available gene signatures and to assess the influence of the 21-gene-expression assay on changes in treatment recommendations.

METHODS

A systematic search of the peer-reviewed literature from January 2002 to March 2014 for multigene predictor assays was carried out, and a meta-analysis was conducted.

RESULTS

The adjusted Cox hazard ratio average for studies that met the eligibility criteria was 3.538 (95% CI: 1.513-8.469). The 21-gene signature showed the highest stability in the estimation of likelihood of distant risk of recurrence. Using the recurrence scores resulted in changes in treatment recommendations in 31.8% of all patients in the studies.

CONCLUSION

This study may provide insight about the use of multigene predictors in clinical practice for prediction and prognosis of breast cancer.

Clinical utility of gene-expression profiling in women with early breast cancer: an overview of systematic reviews

PURPOSE

This overview systematically evaluates the clinical utility of using Oncotype DX and MammaPrint gene-expression profiling tests to direct treatment decisions in women with breast cancer. The findings are intended to inform an updated recommendation from the Evaluation of Genomic Applications in Practice and Prevention Working Group.

METHODS

Evidence reported in systematic reviews evaluating the clinical utility of Oncotype DX and MammaPrint, as well as the ability to predict treatment outcomes, change in treatment decisions, and cost-effectiveness, was qualitatively synthesized.

RESULTS

Five systematic reviews found no direct evidence of clinical utility for either test. Indirect evidence showed Oncotype DX was able to predict treatment effects of adjuvant chemotherapy, whereas no evidence of predictive value was found for MammaPrint. Both tests influenced a change in treatment recommendations in 21 to 74% of participants. The cost-effectiveness of Oncotype DX varied with the alternative compared. For MammaPrint, lack of evidence of the predictive value led to uncertainty in the cost-effectiveness.

CONCLUSION

No studies were identified that provided direct evidence that using gene-expression profiling tests to direct treatment decisions improved outcomes in women with breast cancer. Three ongoing studies may provide direct evidence for determining the clinical utility of gene-expression profiling testing.

Adjuvant aromatase inhibitor therapy in patients with stage I breast cancer at a regional oncology center in Israel: implementation of a 'switching' policy in postmenopausal patients after initial tamoxifen

OBJECTIVE

To analyze the implementation of a switching policy of adjuvant aromatase inhibitor (AI) therapy sequentially after tamoxifen in consecutively treated stage I (T1N0M0) hormone receptor (HR)-positive breast cancer (BC) patients.

METHODS

The records of 279 consecutive HR-positive BC patients diagnosed between 2002 and 2006 and followed at the Soroka Medical Center were reviewed.

RESULTS

Two-hundred-seventeen patients who initially received tamoxifen were suitable for switching and 28 received an AI as initial adjuvant treatment. The switch was accomplished in 82.5% of the 217 patients. Those who switched to an AI had a higher proportion of T1c stage than patients eligible who were not switched, but did not differ in age, histologic grade, or having received chemotherapy. Of the 179 patients who switched, 155 (86.6%) completed at least 4.5-5 years of adjuvant tamoxifen/AI therapy. Eighteen patients discontinued AI therapy prematurely because of toxicity.

CONCLUSIONS

In this stage I BC population, despite the toxicities of AI therapy, >84% of eligible patients received an AI as adjuvant therapy. Measures to improve the management of AI toxicity, such as changing to a different AI, may reduce early stopping.

From High-Throughput Microarray-Based Screening to Clinical Application: The Development of a Second Generation Multigene Test for Breast Cancer Prognosis

Several multigene tests have been developed for breast cancer patients to predict the individual risk of recurrence. Most of the first generation tests rely on proliferation-associated genes and are commonly carried out in central reference laboratories. Here, we describe the development of a second generation multigene assay, the EndoPredict test, a prognostic multigene expression test for estrogen receptor (ER) positive, human epidermal growth factor receptor (HER2) negative (ER+/HER2−) breast cancer patients. The EndoPredict gene signature was initially established in a large high-throughput microarray-based screening study. The key steps for biomarker identification are discussed in detail, in comparison to the establishment of other multigene signatures. After biomarker selection, genes and algorithms were transferred to a diagnostic platform (reverse transcription quantitative PCR (RT-qPCR)) to allow for assaying formalin-fixed, paraffin-embedded (FFPE) samples. A comprehensive analytical validation was performed and a prospective proficiency testing study with seven pathological laboratories finally proved that EndoPredict can be reliably used in the decentralized setting. Three independent large clinical validation studies (n = 2,257) demonstrated that EndoPredict offers independent prognostic information beyond current clinicopathological parameters and clinical guidelines. The review article summarizes several important steps that should be considered for the development process of a second generation multigene test and offers a means for transferring a microarray signature from the research laboratory to clinical practice.