Older Age Modifies Oncologic Outcome Following Radiotherapy in Soft-tissue Sarcoma: A Subtype-specific SEER Analysis

Given the immune-mediated mechanisms of radiotherapy (RT), we hypothesized that age would affect response to RT in patients with soft-tissue sarcoma (STS) undergoing surgery.

Using the Surveillance, Epidemiology, and End Results Program (1990-2011), we identified 15,380 patients with non-metastatic STS. Stratified by age (≥65 years) and histological subtype, we assessed predictors of overall (OS) and disease-specific survival (DSS).

Treatment with RT was associated with improved OS and DSS compared to surgery alone (p<0.05). Multivariate analysis also demonstrated that older patients obtained significant improvements in OS following RT, while younger patients did not. Results for DSS were similar, with older patients with leiomyosarcoma, sarcoma not otherwise specified, and myxoid liposarcoma, in particular, showing greater improvements in DSS after RT than younger patients (p<0.05). Interaction testing demonstrated an impact of year of diagnosis on outcomes but not receipt of RT.

Among patients with STS undergoing surgery, age appears to impact oncological outcomes after RT.