Benefit of adjuvant radiotherapy after breast‐conserving therapy among elderly women with T1‐T2N0 estrogen receptor‐negative breast cancer

BACKGROUND The purpose of the current study was to evaluate the impact of radiotherapy (RT) among women aged ≥ 70 years with T1‐2N0 estrogen receptor (ER)‐negative breast cancer using Surveillance, Epidemiology, and End Results (SEER)‐Medicare‐linked data. METHODS The study included 3432 women, 2850 of whom received and 582 of whom did not receive RT after breast‐conserving surgery. Outcomes were estimated by the cumulative incidence method and compared with the Gray test. The Fine and Gray subdistribution hazard regression models were used to assess the impact of RT and other variables. RESULTS Women who received RT were more commonly aged