Synovial sarcoma outcome following conservation surgery and radiotherapy

Abstract

This retrospective review of 85 patients presents the prognostic factors and disease outcome for localized synovial sarcoma treated with conservation surgery and radiotherapy. Tumors were located in the lower extremity (48), upper extremity (20), trunk (11), and head and neck (6). All patients were treated with limited excision and radiotherapy. Sixty-seven patients had surgery followed by radiation and 18 had preoperative radiation. Postoperative radiation was delivered to a mean dose of 62 Gy, whereas the mean dose for preoperative radiation was 50 Gy. Thirty-five patients, mostly with tumors exceeding 5 cm, received adjuvant adriamycin-based chemotherapy (median adriamycin dose 406 mg/m 2). At a median follow-up of 8.4 years the 5-, 10-, and 15-year survival rates were 76%, 63%, and 57%. Mortality was almost entirely due to metastatic relapse. Metastases developed in 36 patients yielding an actuarial 10-year metastatic rate of 48%. In multivariate analysis, tumor size was the dominant determinant of metastases with a lesser contribution due to patient age (those ≤ 20 years having fewer metastases). Tumor site and histology were not independently significant. Ten-year metastatic rates according to tumor size, s, were s ≤ 2 cm, 0%; 2 < s ≤ 5 cm, 35%; 5 < s ≤ 10 cm, 59%; 10 cm < s, 100%. Our retrospective data failed to reveal benefits for adjuvant chemotherapy either in univariate or multivariate analysis. Eight patients (9%) had local recurrence as the initial failure and 4 others had local failure after disease appeared elsewhere, yielding a 5-year actuarial local recurrence rate of 14%. Local control did not correlate with tumor size, site or radiation dose. The incidence of nodal metastases was only 3%. Conservation surgery and radiation achieves a satisfactory rate of local control in synovial sarcoma. This disease has a high metastatic propensity that correlates with tumor size and determines the fate of the patient. The development of effective systemic therapy is of high priority.