Risk Factors for Distant Metastasis in Patients with Oral Cavity Squamous Cell Carcinoma Undergoing Surgical Treatment.

OBJECTIVE: The aim of this study is to investigate the clinical and pathological factors related to distant metastasis in patients with oral cavity squamous cell carcinoma (OCSCC) undergoing surgery. STUDY DESIGN: A retrospective data review was conducted on patients who underwent primary surgery for OCSCC at the Instituto do Cancer do Estado de Sao Paulo (ICESP) between 2009 and 2015. Distant metastasis rates were calculated and predictive factors were determined by the Cox proportional-hazards model. RESULTS: There was a total of 274 patients, including 210 (76.6%) men and 64 (23.4%) women, with a mean age of 59.9 +/- 10.9 years. The incidence of distant metastasis was 9.6%, with the lung being the most common site. The mean time interval between surgical treatment and the diagnosis of distant metastasis was 12 months (range 2-40 months). In the multivariate analysis, angiolymphatic invasion (HR = 2,87; p = 0.023), contralateral cervical metastasis (HR = 3.3; p = 0,007), tumor thickness >25 mm (HR = 3.50; p = 0.009), and locoregional recurrence (HR = 6.59; p < 0.0001) were the only independent risk factors for distant metastasis. CONCLUSION: Patients with OCSCC who have contralateral lymph node metastasis, tumors with a thickness >25 mm, angiolymphatic invasion, or locoregional recurrence after surgical treatment have a greater risk of developing distant metastasis.