The Influence of SYT-SSX Fusion Gene, E-cadherin and β-Catenin on the Metastasis of Synovial Sarcoma / 中国肿瘤临床

ABSTRACT

Objective: To study the prognostic significance of the subtype of SYT-SSX fusion gene, E-cadherin, β-Catenin and clinicopathologicel parameters for the metastasis of synovial sarcomas. Methods: A total of 98 synovial sar-coma patients with complete clinical and follow-up data were reviewed. RT-PCR was used to detect the subtype of SYT-SSX fusion geneo The expression of E-cadherin and β-catenin was detected by immunohistochemistry. Univariate and multivariate analyses were performed to analyze the influence of the above factors and clinicopathological parameters on the metastasis free survival to explore the factors affecting the metastasis of synovial sarcoma. Results: Of all the pa-tients, 69.4% (68/98) had metastasis during follow-up. The median metastasis free survival was 48 months. The metastasis free 1-, 2-, 3-, 4-, and 5-year survival rate after surgery was 97.5%, 75.5%, 63.5%, 54.0%, and 48.5%, respectively; 31.6% (31/98) patients were found with SYT-SSX1 and 68.4% (67/98) patients with SYI-SSX2. The positive rate of E-cadherin ex-pression was 38.8% (38/98), the positive rate of β-catenin expression was 39.8% (39198) on cellular membrane and 53.1% (52/98) in cellular nucleus/cytoplasm. Univariate analysis showed that age (P=0.003), mitotic figure (P=0.002), histological grade (P=0.001), the subtype fusion gene of SYT-SSX (P=0.014), E-cadherin expression (P=0.015) and β-catenin expres-sion on cellular membrane (P=0.020) were significantly correlated with metastasis free survival of synovial sarcoma pa-tients. Sex (P=0.190), tumor location (P=0.105), tumor size (P=0.180), histological type (P=0.354), necrosis (P=0.451), β-catenin expression in cell nucleus/cytoplasm (P=0.911), radiotherapy (P=0.193), and chemotherapy (P=0.249) had no sig-nificant correlation with metastasis free survival of synovial sarcoma patients. Multivariate analysis revealed that the sub-type of SYT-SSX1 fusion gene (RR=2.505, P=0.003), negative expression of E-cadherin (RR=3.282, P=0.000), patient age (RR=2.157, P=0.004), and grade Ⅲ (RR=1.784, P=0.030) were independent risk factors for metastasis of synovial sarco-ma. Conclusion: The subtype of SYT-SSX, expression of E-cadherin, histological grade and the age of patients are impor-tant factors for evaluating the metastasis and prognosis of synovial sarcoma.