Risk factors of distant metastasis in patients with squamous cell carcinoma of the oral cavity.

OBJECTIVE: Although the locoregional control rate of oral cancer has improved recently, the number of patients developing distant metastasis (DM) has increased. The aim of this study is to investigate the clinicopathologic factors related to DM in patients with oral cancer undergoing surgery. STUDY DESIGN: This was a retrospective study of 252 patients who underwent surgery for squamous cell carcinoma of the oral cavity. Various clinicopathologic factors were examined to determine their relationship to the development of DM. RESULTS: DM occurred in 21 patients. Univariate analysis showed that perineural invasion, pathologically positive lymph nodes (pN+), neck metastasis level, extracapsular spread, local recurrence, neck recurrence, locoregional control, and postoperative radiotherapy were related to the occurrence of DM. According to multiple logistic analyses, pN+, involvement of neck levels 4 and 5, and local recurrence were independent risk factors for DM. CONCLUSIONS: pN+, metastasis to the lower neck, and local recurrence were risk factors for DM in patients with oral cancer.