Radiation-induced sarcomas of the breast: A review of a 20-year single-centre experience

Abstract Purpose Radiation-induced sarcomas (RIS) are histologically proven sarcomas within or around a previously irradiated site, per Cahan’s criteria. RIS incidence is higher in breast cancer compared to other solid cancers and prognosis remains poor given limited treatment options. This study aimed to review 20-year experience with RIS at a large tertiary care centre. Methods Using our institutional cancer registry database, we included patients meeting Cahan’s criteria diagnosed between years 2000 to 2020. Patient demographics, oncologic treatment, and oncologic outcomes data were collected. Descriptive statistics were used to describe demographic data. Oncologic outcomes were assessed using the Kaplan Meier method. Results Nineteen patients were identified. The median age at RIS diagnosis was 72 years (range 39–82) and median latency period for development of RIS was 112 months (range 53–300). All patients underwent surgery, 3 patients received systemic therapy, and 6 patients received re-irradiation as salvage treatment. The median follow-up time was 31 months (range 6-172) from diagnosis of RIS. Overall, 5 patients had local recurrence and 1 patient developed distant metastases. The median time to progression was 7 months (range 4–14). The progression-free survival (95% CI) at two years was 56.1% (37.4–84.4%). At two years follow-up after sarcoma diagnosis, the overall survival (95% CI) was 88.9% (75.5–100%). Conclusion While breast RIS remains rare, when managed in a high patient-volume centre, overall survival outcomes appear favorable. A significant proportion of patients recur locally after maximal treatment and require salvage therapy to improve outcome. These patients should be managed in high-volume centres where multidisciplinary expertise is available.