Synovial sarcoma: prognostic significance of tumor size, margin of resection, and mitotic activity for survival.

ABSTRACT

PURPOSE: The present study serves to describe outcomes-based prognostic variables characteristic of synovial cell sarcoma. PATIENTS AND METHODS: An analysis was performed of a prospectively compiled data base of 48 consecutive patients with extremity and truncal synovial sarcomas seen between 1966 and 1994. RESULTS: No local recurrences were observed among 27 patients who presented with localized primary disease. Patients with synovial sarcoma less than 5 cm in size has a cancer-specific survival rate at 10 years of 100%, compared with a 10-year survival rate of 32% and 0% for those with sarcoma 5 to 10 cm and greater than 10 cm, respectively (P = .002). Patients with synovial sarcoma with less than 10 mitoses per 10 high-power fields (hpf) had a 10-year cancer-specific survival rate of 46%, compared with a 10-year survival rate of 14% for those with sarcomas with greater than 10 mitoses per hpf (P = .04). Patients with a clean margin of excision were found to have a 10-year cancer-specific survival rate of 43%, compared with 0% for those with microscopic positive margins (P = .03). Among 14 patients treated with neoadjuvant chemotherapy, seven (50%) had objective responses. CONCLUSION: Local control for patients with nonmetastatic disease was excellent. The overall cancer-specific survival rate for patients with localized synovial sarcoma was 34% at 10 years. Primary tumor size, margin of resection, and mean mitotic activity were prognostic factors for survival in synovial sarcoma. There was a high objective response rate to treatment with neoadjuvant chemotherapy; however, there was no detectable beneficial effects on survival in the subset of patients treated with chemotherapy versus nonrandomized patients who received no chemotherapy. Patients with synovial sarcoma > or = 5 cm in size, microscopic positive margins, and/or mean mitotic activity greater than 10 mitoses per 10 hpf should be targeted for new therapeutic studies.