Young age is associated with inferior outcomes in early-stage luminal B breast cancer patients who undergo mastectomy.

This retrospective study aimed to evaluate the effect of age on cancer relapse and survival in breast cancer patients undergoing different treatments. The propensity score method was used to correct for disparities between two groups; 2049 young patients were matched to 4053 older patients. Kaplan-Meier curves and Cox proportional hazards models were used to assess disease-free survival. In the original cohort, young patients showed higher lymph node metastasis, hormone-receptor positivity and high Ki-67 levels. After propensity score matching, the disease-free survival of young patients with the luminal B-like subtype who received mastectomy with early stage disease exhibited inferior survival. Decisions about biology-driven systemic treatment strategies for young patients are worthy of discussion with a multidisciplinary tumor board.