MDNews - Long Island

CAREFUL , INDIV IDUALIZED USE of chemotherapy to treat breast cancer is of paramount importance because of the treatment's potential to cause a variety of physical and emotional side effects. Sponsored by the National Cancer Institute (NCI), RxPONDER is one of many studies in which researchers have sought to better understand which patients with breast cancer need chemotherapy and which ones can avoid it. Unlike other large, randomized trials, RxPONDER explored this issue in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer with involvement of one to three lymph nodes. "Two-thirds of breast cancers are HR-positive and HER2- negative," says R xPONDER Principa l Investigator Kevin Kalinsky, MD, MS, Director of the Glenn Family Breast Center at the Winship Cancer Institute at Emory University and Associate Professor in the Department of Hematology and Medical Oncology at the Emory University School of Medicine, interviewed in early 2021. "We did look within SEER [an NCI cancer statistics database] to get a sense of approximately how many patients per year would fit this criterion of involvement of one to three lymph nodes, and of that group, it's about 20%." A PRE- AND POST-MENOPAUSAL DIVIDE The RxPONDER trial included 5,015 patients — two-thirds of whom were postmenopausal — with stage 2 or 3 breast cancer that had spread to one to three lymph nodes and who scored 0–25 on a frequently-used, 21-tumor gene expression assay, the Oncotype DX Breast Recurrence Score (RS) test. Participants were randomized to receive hormone therapy or hormone therapy plus standard chemotherapy. Initial results encompassing 54% of anticipated invasive disease-free survival events and representing a median follow-up period of 5.1 years were presented at the 2020 San Antonio Breast Cancer Symposium. The researchers found that for postmenopausal women, five- year invasive disease-free survival rates of those who received hormone therapy plus chemotherapy and those who received hormone therapy alone were essentially identical — 91.6% and 91.9%, respectively. Premenopausal women who received both treatments had a five-year invasive disease-free survival rate of 94.2% compa red with a rate of 89% for those who only received hormone therapy, a marked difference. The addition of chemotherapy did not improve overall survival for postmenopausa l women. In the premenopausa l group, For Breast Cancer Patients, the RxPONDER Trial Refines the Answer AN INTERIM ANALYSIS CONFIRMS INITIAL RESULTS FROM THE SOUTHWEST ONCOLOGY GROUP (SWOG) PHA SE 3 R XPONDER TRIAL, FINDING THAT POSTMENOPAUSAL WOMEN WITH A COMMON FORM OF BRE A ST CANCER MAY BE ABLE TO FOREGO CHEMOTHER APY — AND ITS POTENTIAL ADVERSE EFFECTS — IN FAVOR OF STANDALONE HORMONE THER APY. BY THOMAS CROCKER Who Needs Chemotherapy? 2 4 SPECIAL CLINICAL SECTION: WOMEN'S HEALTH

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