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.

Abstract

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). We restaged the 342 patients with the revised pT and pN criteria and performed survival analyses. 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. Of the competing AJCC staging criteria, the revised pN classification was the most powerful system to predict OSCC survivals.