Clinical and pathological features of patients with resected synovial sarcoma: a multicenter retrospective analysis of the Anatolian Society of Medical Oncology.

Background: Synovial sarcoma (SS) is a rare disease and compared with other soft-tissue sarcomas has a relatively high mortality rate. The optimal management of this disease and prognostic factors associated with patient outcome remains controversial.

Objective: We aimed to evaluate the factors affecting the outcomes of SS patients in the adjuvant setting.

Methods: In this Turkish multicenter study, we assessed the data of 69 SS patients regarding prognostic factors for SS patients retrospectively.

Results: Our study included 69 localized SS patients (38 males and 31 females) with a median age of 34.5 years (minimum-maximum: 14-68 years). Overall survival (OS) and disease free survival (DFS) rates for 5 years were 64% and 25%, respectively. All patients under went surgical treatment; 64 patients were treated with a wide excision and 5 patients had an amputation. According to the univariate analysis, adverse prognostic factors for OS were male sex, higher mitotic activity, high Ki-67 levels, trunk localization and inadequate surgical margins. In multivariate analysis, none of these factors had independent significant association with OS. Prognostic factors for DFS; in the univariate analysis were higher mitotic activity, high Ki-67 levels and inadequate surgical margins. Only higher mitotic activity (≥10 high-power field) was significantly associated with worse DFS in the multivariate analysis (hazard ratio: 0.30, % confidence interval: 0.11-0.80, P = 0.017).

Conclusions: Our study confirms that high mitotic activity is significantly associated with decreased DFS. The question of whether the chemotherapy provides a survival advantage in patients having adverse prognostic factors requires confirmation in randomized trials.