Dr. Chavez Mac Gregor on Chemotherapy in Node-Positive HR+/HER2- Breast Cancer

Mariana Chavez Mac Gregor, MD, MSc, associate professor, Department of Health Services Research, Division of OVP, Cancer Prevention and Population Sciences, The University of Texas MD Anderson Cancer Center, discusses the use of chemotherapy in patients with node-positive, hormone receptor (HR)-positive, HER2-negative breast cancer.

Patients with HR-positive tumors should receive endocrine therapy, but whether or not all patients with node-positive tumors need to receive chemotherapy remains unclear. Many clinical trials are evaluating this, says Chavez Mac Gregor—specifically, the highly anticipated RxPONDER trial. These trials will shed more light on whether or not patients with 1 to 3 positive lymph nodes with recurrence scores less than 25 benefit from chemotherapy or not.

Retrospective data do suggest that the biology is very important, she adds. Even in this group of higher-risk patients, those with lower recurrence scores may not benefit from chemotherapy.

For example, data from the MINDACT trial, in which the genomic assay MammaPrint was used, showed that patients who are high-risk clinically but low-risk genomically have excellent outcomes. Despite this, many patients with lymph node involvement continue to receive chemotherapy, says Chavez Mac Gregor. However, providers are beginning to learn how to tailor and personalize treatment based not only on the extent of disease, but also its biology.