Wang J, Luo J, Jin K, et al. - Researchers explored how biological subtypes influence locoregional recurrence among Chinese breast cancer patients undergoing postmastectomy radiotherapy (PMRT). A retrospective study of approximately 583 patients who underwent postmastectomy radiation between 2010 and 2012 was performed. Based on immunohistochemical staining profile, participants were split into Luminal A-like, Luminal B-like, HER2-positive, and triple-negative breast cancer (TNBC). The estimated 5-year local and regional recurrence (LRR) cumulative incidence rates for Luminal A, Luminal B, HER2-positive, and TNBC patients were 1.57%, 4.09%, 10.74%, and 10.28%, respectively. A significant heightened risk of LRR was observed in HER2-positive subtype and TNBC vs Luminal A. Independent predictors of LRR identified in the multivariate model were HER2-positive subtype, TNBC, and pN3. Overall, the biological subtype was identified as a prognostic factor of LRR in the PMRT setting in this patient population.