Carcinomas arising in the submandibular gland: High propensity for systemic failure

Background: Cancers of the submandibular gland are uncommon and only a few small series have reported patient survival and prognosis. Methods: We examined the treatment outcomes of 62 patients with surgically treated submandibular gland carcinomas. All patients underwent surgical excision with/without neck dissection, and 41 received postoperative radiotherapy for high-grade, invasive, positive margin, or regionally metastatic tumors. The locoregional control and survival rates were calculated by the Kaplan-Meier method and prognostic factors were calculated from uni- and multivariate analyses. Results: Of the 62 submandibular gland carcinomas, 19 were adenoid cystic, 11 were mucoepidermoid, and 10 were salivary duct carcinomas, and 8 were carcinomas in pleomorphic adenoma. Actuarial 5-year locoregional control, distant metastasis-free survival, disease-free and overall survival rates were 69.7%, 65.8%, 52.8%, and 56.8%, respectively. In multivariate analysis, T category and histological grading were prognostic for disease-free survival (P < 0.01), and T category and resection margins were prognostic for locoregional control (P < 0.02). Distant metastases were found in 21 patients (33.9%) at initial staging (n = 2) or follow-up (n = 19). Conclusions: Despite effective locoregional treatment, approximately one-third of patients with submandibular gland carcinomas may fail systemically, resulting in poor survival. New, more effective therapies may be required for these patients.