Key clinical point: Patients who had survived breast cancer (BC) were more likely to develop soft tissue sarcoma if they received radiotherapy.
Major finding: A very small fraction of BC survivors (~0.1%) developed thoracic soft tissue sarcoma, with radiotherapy being the strongest risk factor in the Kaiser Permanente (KP) cohort (relative risk [RR] 8.1; P = .0052) and the Surveillance, Epidemiology, and End Results (SEER) 13 registries cohort (RR 3.0; P < .0001).
Study details : This retrospective study of data sourced from two cohorts, the KP cohort (n = 15,940) and the SEER 13 registries cohort (n = 457,300) and included patients who had BC surgery and survived ≥1 year after BC diagnosis.
Disclosures: This study was supported by the US National Cancer Institute and National Institutes of Health. The authors declared no conflicts of interest.
Source: Veiga LHS et al. Treatment-related thoracic soft tissue sarcomas in US breast cancer survivors: A retrospective cohort study. Lancet Oncol. 2022;23(11):1451-1464 (Oct 11). Doi: 10.1016/S1470-2045(22)00561-7