UC Davis

Background

Neoadjuvant radiotherapy (RT) is increasingly advocated for the management of soft tissue sarcoma (STS). Therefore, this study sought to characterize the impact of neoadjuvant RT on rates of R0 resection and overall survival (OS) in extremity STS patients undergoing surgery.

Methods

From January 2003 to December 2012, the study identified patients with a diagnosis of extremity STS from the National Cancer Database. After exclusion of patients younger than 18 years, not treated by surgery, who had metastases at diagnosis, intraoperative RT, and missing or unknown data, 27,969 patients were identified. Logistic regression and Cox-proportional hazard analysis were used to compare rates of R0 resection among preoperative, postoperative, and no-RT cohorts and to determine predictors of R0 resection and OS.

Results

The mean age of the patients was 59.5 ± 17.1 years, and 45.9% were female. The median tumor size was 10.5 cm. The data showed that 51% of the patients did not receive RT, 11.8% received preoperative RT, and 37.2% received postoperative RT. The rates of R0 resection were 90.1% for the preoperative RT cohort, 74.9% for the postoperative RT cohort, and 79.9% for the no-RT cohort (P < 0.001). The independent predictors for achievement of R0 resection included academic facility type (odds ratio [OR] 1.36; 95% confidence interval [CI] 1.20-1.55), histologic subtype, tumor size (OR 0.99; 95% CI 0.99-0.99), Charlson score (OR 0.92; 95% CI 0.84-0.99), and preoperative RT (OR 1.83; 95% CI 1.61-2.07). Both R0 resection and RT (pre- or post-operative) were associated with increased OS.

Conclusions

Preoperative RT independently predicts higher rates of R0 resection for patients with extremity STS undergoing surgical resection. Negative surgical margins and pre- or postoperative RT are associated with improved OS.