Impact of smoking on pathological features in oral cavity squamous cell carcinoma

We sought to determine whether smokers with oral cavity squamous cell carcinoma (OCSCC) have tumors with more adverse pathological features than in nonsmokers and whether or not these are predictive of outcomes.

We retrospectively identified 163 patients with American Joint Committee on Cancer stages I-IVa OCSCC diagnosed between 2005 and 2015 and treated with curative intent. A pathological risk score (PRS) was calculated using the National Comprehensive Cancer Network adverse risk factors: positive margin, extracapsular extension of lymph node metastases, pT3 or pT4 primary, N2 or N3 nodal disease, perineural invasion, and lymphovascular space invasion. Multivariable models were constructed to determine the independent predictors of overall survival (OS), recurrence-free survival (RFS), and PRS.

A total of 108 (66.26%) were smokers and 55 nonsmokers. Three-year actuarial OS and RFS were 62% and 68% in smokers and 81% and 69% in nonsmokers, respectively (P = 0.06 and P = 0.63). Smokers were more likely to have advanced disease stage and tumors with aggressive pathological features than nonsmokers. Smokers had significantly worse PRS (mean ± standard deviation; 2.38 ± 2.19, median; 2.00) than nonsmokers (0.89 ± 1.21, 0.00) (P < 0.001). Older age, higher PRS, and smoking status were independent predictors of OS. Smoking or PRS did not predict for worse RFS. On multivariate analysis, independent predictors of PRS were smoking status and grade (P < 0.001).

In patients with OCSCC, smokers have more aggressive disease as evidenced by more adverse pathological features than nonsmokers. Moreover, smoking is an independent predictor of OS but not RFS. The PRS is a significant predictor of OS and needs validation in the future studies.