Surgical margins and reresection in the management of patients with soft tissue sarcoma using conservative surgery and radiation therapy

BACKGROUND. Patients with localized soft tissue sarcoma (STS) who present to specialist centers after undergoing apparent macroscopic total resection often have a significant incidence of residual tumor and may benefit from reresection of the tumor bed. The potential benefits of such reresection have not been documented adequately. METHODS. The clinicopathologic features and disease outcome for 666 consecutive patients with localized STS who presented after undergoing apparent macroscopic total tumor resection were analyzed to elucidate the relative merits of reresection. Actuarial univariate and multivariate methods were used to compare disease outcome of patients who presented with positive or uncertain microscopic resection margins according to whether they underwent reresection. All patients received adjuvant radiation therapy. RESULTS. Two hundred and ninety-five patients underwent reresection of their tumor bed, and residual tumor was found in 136 patients (46%), including macroscopic tumor in 73 patients (28%). Final resection margins among patients who underwent reresection were negative in 257 patients (87%), positive in 35 patients (12%), and uncertain in 3 patients (1%). Patients who did not undergo reresection had final margins that were negative in 117 patients (32%), positive in 47 patients (13%), and uncertain in 207 patients (56%). Local control rates at 5 years, 10 years, and 15 years for patients who underwent reresection were 85%, 85%, and 82%, respectively; for patients who did not undergo reresection, the respective local control rates were 78%, 73%, and 73% (P = 0.03). Reresection remained a significant determinant of local control when other prognostic factors were incorporated into a multivariate proportional hazards regression analysis. A similar beneficial effect of reresection was found for metastasis free survival and disease specific survival. CONCLUSIONS. Patients with localized STS who were referred to a specialist center after undergoing apparent macroscopic total resection of their tumor had a high incidence of residual tumor in their tumor bed and benefited from undergoing reresection, even if radiation was administered routinely.