Long-term outcomes for synovial sarcoma treated with conservation surgery and radiotherapy

To evaluate prognostic factors and treatment outcomes in patients with localized synovial sarcoma treated with conservation surgery and radiotherapy (RT).

Between 1960 and 2003, 150 patients with nonmetastatic synovial sarcoma were treated with conservation surgery and RT. The majority of patients (81%) were aged >20 years. Sixty-eight percent received postoperative RT, and 32% received preoperative RT. Forty-eight percent received adjuvant chemotherapy.

Median follow-up was 13.2 years. Overall survival (OS) rates at 5, 10, and 15 years were 76%, 57%, and 51%, respectively. Corresponding disease-free survival (DFS) rates were 59%, 52%, and 52%, respectively. Tumor size >5 cm predicted worse OS, DFS, disease-specific survival (DSS), and higher rate of distant metastases (DM). Age >20 years predicted worse DFS and DSS but not OS. Local control (LC) was 82% at 10 years. Positive or unknown resection margins predicted inferior LC rates. Forty-four percent developed DM by 10 years. Only 1% developed nodal metastases. Analysis of outcomes by treatment decade showed no significant differences with respect to LC and DM rates.

Synovial sarcoma is adequately controlled at the primary site by conservation surgery and RT. Elective nodal irradiation is not indicated. Rates of development of DM and subsequent death from disease remain high, with no significant improvement in outcomes for this disease in the past four decades.