Prognostic Performance of a New Staging Category to Improve Discrimination of Disease-Specific Survival in Nonmetastatic Oral Cancer.

Importance: Inflammatory status is associated with outcome in oral squamous cell carcinoma (OSCC). Combining the preoperative neutrophil to lymphocyte ratio (NLR) and histopathologic features may provide clinicians with more exact information regarding the prognosis of OSCC.

Objective: To compare the prognostic performance of the routinely used pathologic TNM staging with a new staging category that incorporates the NLR and histopathologic features.

Design, Setting, and Participants: This retrospective cohort study included 396 patients with newly diagnosed OSCC who underwent major surgery at a medical center from January 1, 2006, through December 31, 2013. Follow-up was completed on October 31, 2015, and data analysis was performed from January 1, 2016, through April 30, 2016.

Main Outcomes and Measures: The multivariate Cox proportional hazards regression model was used to determine the clinical or pathologic factors associated with 5-year disease-specific survival (DSS), and these factors were assigned integer points to create a new staging category. The monotonicity and discriminatory ability of the pathologic TNM staging and new staging category were evaluated with the linear trend χ2 test, Akaike information criterion, and Harrell C statistic.

Results: In total, 396 patients who underwent major surgery with curative intent for OSCC with or without adjuvant therapy were included in this study (mean [SD] age, 53 [11] years; 367 men [92.7%] and 29 women [7.3%]). Perineural invasion (adjusted hazard ratio [aHR], 1.74; 95% CI, 1.23-2.46), high NLR (aHR, 1.60; 95% CI, 1.11-2.30), advanced pT (T3 + T4) classification (aHR, 1.59; 95% CI, 1.13-2.25), and advanced pN (N2) classification (aHR, 3.96; 95% CI, 2.78-5.63) were independent prognostic survival factors. The β coefficients from the Cox proportional hazards regression model were used to develop an integer-based weighted point system (perineural invasion, score of 1; NLR, score of 1; advanced pT, score of 1; and advanced pN, score of 3). The summations of these risk scores were stratified for the new staging category as follows: new stage I, score of 0; new stage II, score of 1; new stage III, score of 2 or 3; and new stage IV, score of 4 to 6. Compared with the American Joint Committee on Cancer staging category, this new staging category provided better monotonicity with a higher linear trend χ2 value (106 vs 49), better discriminatory ability with smaller Akaike information criterion (1497 vs 1533), and greater Harrell C statistic (0.73 vs 0.69) for 5-year DSS. The results remained robust after adjusting other risk factors.

Conclusions and Relevance: In this study, new staging category had better DSS discriminatory ability and could help to identify high-risk patients for intense adjuvant therapy.