Adverse pathologic features in T1/2 oral squamous cell carcinoma classified by the American Joint Committee on Cancer eighth edition and implications for treatment

BACKGROUND: The American Joint Committee on Cancer (AJCC) eighth edition has incorporated depth of invasion into TNM classification of oral cavity squamous cell carcinoma (SCC) due to the prognostic impact on recurrence and survival. After reclassifying our patients with T1 to T2 oral cavity SCC according to these recommendations, we intended to study the effect of adverse pathological features (perineural invasion PNI, lymphovascular invasion, and differentiation) on overall survival (OS). METHODS: We conducted a retrospective analysis of 442 patients with T1 to T2 oral cavity SCC. Univariate and multivariate analysis was performed for impact of adverse pathological features on OS. RESULTS: For the newly reclassified T1 to T2 oral cavity tumors, on multivariate analysis, the prognostically relevant parameters were PNI (P = .032) and differentiation (P = .009). Increasing adverse pathological features resulted in worse survival (P = .005). CONCLUSION: Incorporation of PNI and differentiation better reflect prognostic outcome in oral cavity tumors classified as T1 to T2 as per the new AJCC eighth edition. Increasing adverse pathological features resulted in worse survival.