Adjuvant Chemotherapy for HR-Positive <i>ERBB2-</i> Negative Breast Cancer—Clinical Practice Changes Based on TAILORx and RxPONDER Results

Elsewhere in JAMA Network Open, Freeman et al 6 analyze national trends in adjuvant chemotherapy use for early-stage, hormone receptor (HR)-positive, ERBB2-negative breast cancer, node-negative (N0) or pN1 positive (N + ), leveraging data from more than 500 000 women in the National Cancer Database (NCDB) between 2010 and 2022.Their findings reveal a nuanced evolution of practice patterns following the publication of the results of TAILORx and RxPONDER-2 landmark trials that redefined how the 21-gene genomic assay, OncotypeDX Recurrence Score (RS), can inform adjuvant therapy decisions. 1,2While chemotherapy use declined overall, the study found that among premenopausal women with N + disease and a low or intermediate RS (<26), adjuvant chemotherapy receipt nearly doubled between 2019 and 2022.In contrast, adjuvant chemotherapy receipt continued to steadily decline in premenopausal N0 and postmenopausal (N0 or N + ) patients.Importantly, Black women and those with limited or public insurance were consistently less likely to receive chemotherapy, regardless of clinical or genomic risk, underscoring ongoing disparities in access to and receipt of appropriate treatment.The TAILORx trial randomized patients with early-stage, N0, HR-positive breast cancer and an RS between 11 and 25 to receive adjuvant endocrine therapy with or without chemotherapy.The trial demonstrated no chemotherapy benefit in patients older than 50 years.However, in patients aged 50 years or younger, there was a detectable benefit from chemotherapy, with roughly 1.6% and 6.5%