A combined prognostic factor for improved risk stratification of patients with oral cancer

Purpose: We aimed to identify a combined prognostic factor for predicting better performance in risk stratification. Materials and Methods: We reviewed the clinical and pathological variables of 316 patients with oral squamous cell carcinoma (OSCC) who underwent surgery. To identify a combined predictor, principal component analysis (PCA) was performed. Results: Univariate analysis showed that the independent prognostic variables for overall survival (OS) were pathologic T stage (T1 vs T4, HR = 1.99, 95% CI: = 1.083–3.675, P = 0.026) and pathologic N stage (N0 vs N2, HR=1.90, 95% CI: = 1.17–3.08, P = 0.008). In the multivariate analysis, only pathologic T stage was significant (P = 0.006 and P = 0.007); however, the multivariate model was not significant (P = 0.191). The multivariate model became significant by including lymph node ratio (LNR) instead of pathologic N stage (P = 0.0025 in numeric LNR, P = 0.0007 in categorized LNR). Also, the performance of prediction model was improved by a combined prognostic factor (P = 0.0002). Conclusions: The newly identified combined prognostic factor included resection margin, differentiation, and LNR, and they were insignificant factors independently except for LNR. This combined prognostic factor showed a good performance although it did not include molecular markers; therefore, it may be used conveniently for risk stratification of patients with OSCC by combining only clinical information.