Controversies on chemotherapy for early HR+/HER2− breast cancer: the role of anthracyclines and dose intensification

Abstract

Purpose of review: Use of adjuvant chemotherapy significantly reduced the risk of recurrence and improved overall survival (OS) in patients with early-stage breast cancer. However few data are available on efficacy of different adjuvant chemotherapy regimens and schedules in patients with hormone receptor positive/HER2-negative (HR+/HER2−) breast cancer. We aim to summarize the available evidence on efficacy of adjuvant anthracycline-based chemotherapy and of the dose-dense schedule in this population. Moreover, current controversies in the management of patients with early-stage HR+/HER2− breast cancer are discussed. Recent findings: Patient-level meta-analysis evaluating the role of the addition of anthracycline to taxane-based chemotherapy showed that recurrence rate was 14% lower [relative risk (RR) 0.86, P = 0.0004] among patients receiving anthracycline-based treatment. Patient-level meta-analysis evaluating the role of different schedules of chemotherapy administration showed that the use of adjuvant dose-dense chemotherapy is associated with significant reduction in breast cancer recurrences and breast cancer mortality. Less evidence is available in the neoadjuvant setting. Summary: For patients with high-risk HR+/HER2− breast cancer, (neo) adjuvant anthracycline and taxane-based chemotherapy, and a dose-dense regimen should still be considered the standard of care. However, in patients with intermediate-low risk breast cancer anthracycline-free regimens could be considered an option of treatment.