After a median follow-up of 5.1 years, among women with lymph node-positive early-stage breast cancer and a recurrence score of 25 or lower who received adjuvant endocrine therapy with or without chemotherapy, postmenopausal patients had no added benefit from chemotherapy, while premenopausal patients who received chemotherapy had improved invasive disease-free survival (IDFS) and an early indication of improved overall survival (OS), according to data from the SWOG S1007 RxPONDER clinical trial presented during General Session 3 at SABCS 20 on Thursday, Dec. 10.
“The most common form of breast cancer is hormone receptor (HR)-positive and HER2-negative, comprising about two-thirds of all invasive breast cancers,” said Kevin Kalinsky, MD, MS, director of the Glenn Family Breast Center at Winship Cancer Institute of Emory University.
RxPONDER was designed and run by SWOG Cancer Research Network with support from the National Cancer Institute. It set out to determine which patients with HR-positive, HER2-negative breast cancer and one to three positive axillary lymph nodes benefit from chemotherapy and which patients could safely avoid chemotherapy and still achieve similar outcomes with endocrine therapy alone.