Clinicopathological analysis of 502 patients with oral squamous cell carcinoma with special interest to distant metastasis.

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity. Distant metastasis (DM) especially bone metastasis (BM) may reduce patients' quality of life and affects the clinical outcome. We performed clinicopathological analysis of 502 patients with OSCC undergoing radical surgery in order to evaluate the correlation values of clinicopathological features for OSCC with special interest in DM. DM was found in 54 cases and among them 44 and 25 cases had pulmonary metastasis (PM) and BM, respectively. Advanced T stage, positive N stage, lower histologic grade and higher score YK classification were the independent significant prognostic factors found in our series of 502 cases of OSCC. Positive lymph node was the most important prognostic factors in DM and BM; on the other hand, in PM, it was lower histological grade. All patients with BM except one had vertebral bone metastasis. These characteristics of DM, including BM and PM, of OSCC are useful for understanding the metastatic process of OSCC.