Analysis of risk factors for distant metastases in squamous cell carcinoma of the oral cavity

BACKGROUND. The number of patients with oral cavity squamous cell carcinoma (OSCC) is increasing. Because the characteristics of patients with OSCC who develop distant metastases (DM) remain uncertain, the authors analyzed potential risk factors. METHODS. For this report, the authors retrospectively reviewed data from 889 consecutive patients with OSCC who underwent radical surgery from January 1996 to November 2004. Patients were divided into 2 groups according to whether they had either achieved locoregional control (Group A; n = 678 patients) or developed a locoregional recurrence (Group B; n = 211 patients). Cox proportional-hazards models were used to identify independent predictors of the 5-year DM rate. RESULTS. in the entire study cohort, the 5-year DM rate was 9.6% (6.6% for Group A and 21.4% for Group B). In Group A, the number of positive lymph nodes (>= 5; P = .009) and the presence of extracapsular spread (ECS) (P < .001) were independent risk factors for DM. In Group B, the presence of ECS (P = .008), poor differentiation (P = .040), pathological stage >= III (P = .036), and the presence of neck recurrence (P = .001) were independent prognosticators. CONCLUSIONS. The current results indicated that different risk factor categories according to locoregional control may be used to facilitate the selection of appropriate management for patients with OSCC after they undergo radical surgery.