Oncologic Outcomes in Patients with Localized, Primary Head and Neck Synovial Sarcoma.

this study aims to evaluate the survival outcomes of patients suffering from head and neck synovial sarcoma (HNSS), especially in relation to patients with a localized disease at diagnosis. this retrospective chart review includes 57 patients diagnosed with primary HNSS between 1981 and 2020 who presented with a localized disease at diagnosis. Overall survival (OS) from diagnosis, local recurrence-free survival (LRFS), and metastasis-free survival (MFS) from the end of the primary tumor treatment are estimated. The Kaplan-Meier method, the log-rank test, and the Cox proportional hazards regression are used. the 5-year OS, LRFS, and MFS are estimated at 80.4% (95% CI: 66.6%, 88.9%), 67.7% (95% CI: 50.0%, 80.4%), and 50.6% (95% CI: 34.4%, 64.8), respectively. Compared to patients undergoing surgical resection alone, those receiving radiation therapy (RT) with surgery have better LRFS (HR: 0.03, 95% CI: 0.001, 0.57), and those undergoing neo/adjuvant chemotherapy with surgery and RT have better MFS (HR: 0.10, 95% CI: 0.01, 0.95). Moreover, among the patients with tumors ≥ 4 cm, those subject to neo/adjuvant chemotherapy have significantly better MFS (5-year MFS: 53.2%, 95% CI: 29.0%, 72.5%) than those treated with surgery and RT alone (5-year MFS: 20.0%, 95% CI: 0.8%, 58.2%) (LR- = 0.003). overall, the prognosis of HNSS patients looks favorable. Perioperative RT significantly improves local control, and perioperative chemotherapy plays a vital role in delaying metastasis formation in patients with primary HNSS when diagnosed with a localized disease. Importantly, we recommend that systemic therapy should be considered for HNSS patients with tumors ≥ 4 cm.