c-MYC expression in T (III/IV) stage oral squamous cell carcinoma (OSCC) patients.

c-MYC has been noted in many tumor types, but its functional significance and clinical utility in oral squamous cell carcinoma (OSCC) are not well known. Here we studied the expression of c-MYC in correlation to clinical outcome in patients with oral squamous cell carcinoma. The current study, using immunohistochemical staining, first examined c-MYC expression in OSCC patients and further correlated its expression with clinicopathological parameters. c-MYC was expressed in the majority of OSCC patients (n=133). The c-MYC expression is associated with histological grade (=0.0205) of patients with oral squamous cell carcinoma. Multivariate Cox regression analysis revealed that TN stage (<0.001), American Joint Committee on Cancer (AJCC) stage (<0.0001), and tumor differentiation (=0.0025) were independent factors for overall survival in patients with OSCC except for c-MYC expression (>0.05). Multiplicative-scale interaction between T stage (III/IV) and low c-MYC expression on mortality risk was identified (=0.0233). Kaplan-Meier survival analysis demonstrated that oral cancer patients (T III/IV stage) with high c-MYC expression had better survival than those with low and medium c-MYC expression (=0.0270). Our data indicate that c-MYC is a potential biomarker that can be used as a therapeutic target for treating OSCC patients with T stage (III/IV).