Oral squamous cell carcinoma grading systems--analysis of the best survival predictor.

Background: The TNM system has been used for decades in an attempt to predict clinical behavior and appropriate therapy for oral squamous cell carcinomas. Histopathologic classifications can be useful as an additional predictive tool. The purpose of this study was to apply four grading systems (Multiparameter Grading System, Malignancy Grading of the Deep Invasive Margins, World Health Organization grading system, and Histologic Risk Assessment) to oral squamous cell carncinomas and evaluate each system based on clinicopathologic parameters and patient survival.