Clear cell sarcoma of soft tissue: a retrospective review and analysis of 31 cases treated at Istituto Ortopedico Rizzoli.

INTRODUCTION: Clear cell sarcoma (CCS) of soft tissue is a rare melanocytic soft tissue sarcoma with different cytogenetic and natural history than that of melanoma. Objective of this study was to determine outcome predictors in patients treated in our Institute. This objective included the effectiveness of surgical intervention and disease progression after surgery. MATERIALS AND METHODS: Thirty-one patients were diagnosed at our institute with clear cell sarcoma through tissue pathology and immunohistochemistry. Patients received multimodality treatment (surgery, radiotherapy and chemotherapy). Five-year survival rates and prognostic predictors were determined. RESULTS: Sixteen patients were males and 15 females with a median age of 37 years (8-72-years). Twenty-eight tumors were located in extremities and 3 in the trunk area. Eight patients had metastases at their first presentation (6 local lymph nodes and 2 pulmonary metastases). Five and ten-year disease-specific survival rates were 56% and 41%. Two-year disease-specific survival rates for lymph node and pulmonary metastasis groups were 40% and 0%. All metastatic patients died within 5 years follow-up. Five and ten-year disease-specific survival rates for localized tumor cases were 72% and 53%. Male gender, less than 30-years of age, trunk tumor location and size greater than 5 cm were poor prognostic factors according to univariate analysis. Tumor location in the trunk was the only negative prognostic determinant in multivariate model. CONCLUSIONS: Although surgical treatment may be beneficial for tumors without systemic involvement, new chemotherapeutic agents and molecular targeted therapy should be implemented to improve the oncologic outcome in both early and late stage disease.