Radiation-induced angiosarcoma of the breast: individual participant meta-analysis of Japanese population

Background Radiation-induced angiosarcoma (RIAS) of the breast is a very rare and poor prognostic disease. According to previous studies, the efficacy of chemotherapy for RIAS is still controversial. However, no study has assessed the prognosis of RIAS and the prognostic impact of preoperative or postoperative chemotherapy in Japanese patients. Our study aimed to assess them in Japanese people using publication data with our three patients. Methods Thirty-nine patients diagnosed with RIAS, including 36 patients from 34 published case series, and three patients from our hospital were used for analysis. Disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) were assessed. Results Among the 39 patients, 36 patients (92.3%) underwent surgery. The median DFS and OS periods were 14 months (range 1–75 months) and 23 months (range 4–84 months), respectively. Chemotherapy with taxane-based regimen was administered in 13 cases (33.2%) pre- or post-operatively. DFS was significantly improved with chemotherapy in addition to surgery ( p = 0.037). However, addition of chemotherapy to surgery did not improve DDFS ( p = 0.09) and OS ( p = 0.878). In multivariate analysis, age ≥ 70 years was an independent but poor prognostic factor of DFS. Additionally, a lack of chemotherapy showed a trend to be associated with worse DFS. There was no independent variable contributing to DDFS and OS. Conclusions Chemotherapy may have reduced the recurrence rate of RIAS in Japanese patients but did not improve OS. Further data are needed to confirm the efficacy and proper regimen of chemotherapy.