Extremity soft tissue sarcoma: Adding to the prognostic meaning of local failure

Background: We explored the prognostic meaning of local relapse and surgical margins in adult soft tissue sarcoma of the extremities. Methods: Out of a series of 1017 patients with extremity soft tissue sarcoma treated over 20 years, we picked a group of 238 patients operated on at our institution for their first local relapse: 88 after their primary operation performed at the same center and 150 elsewhere. At operation for relapse, margins were microscopically negative in 77% and 75% of patients, respectively. Median follow-up was 107 months. Results: The 10-year mortality rate was 22% in the absence of local relapse, whereas in locally relapsing patients it was 54% and 43%, respectively, for patients first operated on at our institute and for those who were not. The hazard ratio of positive versus negative surgical margins was 1.7 for cause-specific death and 2.1 for distant metastases in patients first operated on at our institute, as opposed to 1.2 and 1.3 for the others. Conclusions: Local relapse was an unfavorable prognostic factor. In the face of a consistent surgical policy for local relapse in a single-institution setting, patients relapsing after the first operation performed at our institution received rescue treatment less frequently than those previously operated on outside a referral center. This is likely due to an inherently higher tumor aggressiveness. In the presence of such a higher aggressiveness, the adequacy of surgical margins at operation for first relapse seemed more critical prognostically. This may have clinical and speculative implications.