Clinicopathological and prognostic implications of genetic alterations in oral cancers.

This study evaluated the clinicopathological and prognostic implications of genetic alterations characterizing oral squamous cell carcinoma(OSCC). Comparative genomic hybridization(CGH) was used to identify chromosomal alterations present in primary OSCCs obtained from 97 pateints. In this population, tobacco use was a significant risk factor for OSCC. By contrast, all 97 of our samples are negative for human papillomavirus (HPV) DNA integration, which is another known risk factor for OSCC in certain populations. Results of the Fisher's exact test followed by Benjamini-Hochberg correction for multiple testing, showed a correlation of 7p gain and 8p loss with node-positive OSCC (p≤0.04 for both genetic alterations) and association of 11q13 gain with high-grade OSCC (p≤0.05). Univariate Cox-proportional hazard models, also corrected for multiple testing, showed significant association of 11q13 gain and 18q loss with decreased survival (p≤0.05). These findings were supported by multivariate analysis which revealed that 11q13 gain and 18q loss together serve as a strong bivariate predictor of poor prognosis. In conclusion, our study has identified genetic alterations that correlate significantly with nodal status, grade, and poor survival status of OSCC. These potential biomarkers may aid the current TNM system for better prediction of clinical outcome.