National Cancer Database analysis of adjuvant chemotherapy use for HR-positive, HER2-negative breast cancer after the TAILORx and RxPONDER trials

Since 2018, the TAILORx and RxPONDER trials have demonstrated that the 21-gene recurrence score (RS) can be indicative of the benefit of adjuvant chemotherapy in HR-positive, HER2 negative breast cancer with 3 or fewer positive lymph nodes. However, its applicability to key subgroups with high risk for recurrence, including premenopausal women with positive lymph nodes and racial and ethnic minority individuals, remains unclear. A retrospective cohort study using the 2010 to 2022 National Cancer Database assessed the temporal patterns of and disparities in adjuvant chemotherapy use in early-stage HR-positive, HER2-negative breast cancer by age, genomic risk, and nodal involvement. In this cohort study of 504,937 women, adjuvant chemotherapy use nearly doubled in premenopausal patients with node-positive tumors and low or intermediate RS from 2019 to 2022, but decreased for women with node-negative disease. The authors conclude that these findings highlight the variability in genomic assay use to inform adjuvant systemic therapy recommendations in HR-positive, HER2-negative breast cancer.