Comparison of the Seventh and Eighth Editions of the American Joint Committee on Cancer pT and pN Classifications as Predictors of Survival in Patients With Oral Squamous Cell Carcinoma.

Objectives: We retrospectively compared the seventh and eighth editions of American Joint Committee on Cancer (AJCC) TNM frameworks as disease-free survival (DFS) and overall survival (OS) predictors in oral squamous carcinomas (OSCCs). Methods: We restaged the 342 patients with the revised pT and pN criteria and performed survival analyses. Results: The 3-year DFS (mean follow-up, 364 days; recurrences, 99) was 50%, and the 5-year OS (mean follow-up, 615 days; deaths, 69) was 42%. The eight edition pN classification was an independent multivariate survival predictor. The revised TNM criteria upstaged pT, pN, and stage groupings in 99 (38.8%), 58 (37.3%), and 101 (29.5%) patients. The latter two groups revealed significantly worse DFS and OS compared with those whose categorizations had remained unaltered. In addition, their classification/staging criteria demonstrated superior discrimination, monotonicity, and accuracy for survival estimations. Conclusions: Of the competing AJCC staging criteria, the revised pN classification was the most powerful system to predict OSCC survivals.