Analysis of risk factors of predictive local tumor control in oral cavity cancer.

Abstract

Survival in oral cavity squamous cell carcinoma (OSCC) depends heavily on locoregional control. In this study, we sought to determine the independent prognosticators for local tumor control, disease-specific survival (DSS), and overall survival (OS) rates in a series of OSCC patients undergoing radical surgery. We retrospectively reviewed 827 consecutive OSCC patients undergoing radical surgery from January 1998 to March 2005. Postoperative radiotherapy was performed in patients with pT4 tumors, positive lymph node(s), or close margins (< or = 4 mm). Local control rates and survivals were plotted using the Kaplan-Meier method. On multivariate analysis (MVA), unfavorable prognostic factors for local control were pathological margins < or = 7 mm (P < 0.001), pathological tumor depth > or = 10 mm (P < 0.001), pathological positive lymph node(s) (P = 0.001), and the presence of betel quid chewing (P = 0.012). The same predictors, with the exception of betel quid chewing and pathological positive lymph node(s), were independently associated with DSS and OS in MVA. A prognostic scoring system was formulated by summing up the four significant local control covariates from MVA. Patients with scores of 3-4 had a significantly poorer local control rate compared to patients with scores of 0-2 (score 3 versus score 0-2: P < 0.001; score 4 versus score 0-2: P < 0.001) Taken together, our data suggest that pathological margins and pathological tumor depth are major independent prognosticators not only for local tumor control, but also for DSS and OS.