While the quality of surgery is similar, recommendations regarding radiation therapy (RT) and chemotherapy (CT) for subtypes of extremity soft-tissue sarcoma (eSTS) vary among cancer institutions. The goal of this study was to learn if differences in RT and CT use affected outcomes in patients with eSTS.
All adults with primary eSTS who underwent surgery at 3 European and 1 North American centers between January 1994 and December 2013 were included in this retrospective analysis. Five- and 10-year overall survival (OS) and crude cumulative incidence of local recurrence (LR) and distant metastases (DM) were calculated.
A total of 3752 patients were analyzed. Adjuvant or neoadjuvant RT and CT were administered to 50% and 2%, 48% and 26%, 82% and 52%, 68% and 2% of patients in the 4 institutions, respectively, reflecting distinctly different treatment patterns.
Grade, histologic subtype, surgical margins, and administration of adjuvant/neoadjuvant RT were significant predictors for LR. Higher LR risk correlated with lower use of adjuvant/neoadjuvant RT in all histology subtypes. Patients with myxoid liposarcoma, myofibrosarcoma, and vascular sarcoma benefited from RT most. OS was not affected by RT use.
The analysis of DM rates showed that tumor size, grade, and histologic subtype significantly predicted DM. In some subtypes, including undifferentiated pleomorphic sarcoma, use of CT suggested a lower risk of DM. However, CT use did not affect OS.
Callegaro D, et al. CTOS 2016. Abstract 2570259. Paper 3.