Prognosis of T1 synovial sarcoma depends upon surgery by oncologic surgeons

Background: The prognosis of early stage synovial sarcomas is not well-defined since long-term follow-up is lacking in most studies. The optimal use of surgery, radiation, and chemotherapy needs to be clarified for this group. Methods: From 1994 to 2012, 63 patients were treated for localized synovial sarcoma with T1 (<5 cm) tumors. There were 27 males and 36 females. Mean follow-up was 85 months (range 13–210). Results: At 10 years, local recurrence-free survival was 82% (95% confidence interval [CI] 67–97%), and distant recurrence-free survival was 95% (95%CI 89–100%). Two patients developed metastases after 10 years. Local recurrence was associated with lack of re-excision and treatment by non-oncologic surgeons. Microscopic residual tumor was found in 43% of re-excised specimens. Metastasis was associated with local recurrence, tumor size ≥3 cm, and treatment by non-oncologic surgeons. Radiation and chemotherapy treatment did not have a significant effect in this patient cohort. Conclusions: Early stage synovial sarcomas with T1 tumors have a relatively favorable prognosis but the potential for late relapse, and long-term follow-up beyond 10 years is recommended. Re-excision of the tumor bed and definitive treatment by trained oncologic surgeons may decrease the risk of local recurrence and metastasis. J. Surg. Oncol. 2016;114:490–494.