Histologic Grade, But Not SYT-SSX Fusion Type, Is an Important Prognostic Factor in Patients With Synovial Sarcoma: A Multicenter, Retrospective Analysis

TLDR: For patients with localized SS, histologic grade but not SYT-SSX fusion type is a strong predictor of survival.

Abstract: Purpose To assess the prognostic value of SYT-SSX fusion type, in comparison with other factors, in a population of 165 patients with synovial sarcoma (SS). Patients and Methods Data on 165 patients with SS (141 with localized disease at diagnosis) were studied retrospectively. The following parameters were examined for their potential prognostic value: age at diagnosis, sex, tumor site (extremities v proximal/truncal), size, histology, mitotic count, necrosis, histologic grade (Federation Nationale des Centres de Lutte Contre le Cancer system), stage (1997 tumor-node-metastasis system classification), surgical margin status (assessed histologically), and fusion type (SYT-SSX1 v SYT-SSX2). Median follow-up time was 37 months (range, 2 to 302 months). Results Among those patients with localized disease at diagnosis, median and 5-year disease-specific survivals (DSS) for the SYT-SSX1 and SYT-SSX2 subgroups were 126 months and 67.4% versus 82 months and 63.2%, respectively (P = .12). Median and 5-year metast...