Evaluation of pathologic staging using number of nodes in p16-negative head and neck cancer.

Abstract

The 8th edition AJCC staging guidelines for head and neck squamous cell carcinoma (HNSCC) recently introduced pathologic staging criteria for nodal disease among p16-positive patients. In this study we evaluate pathologic staging in p16-negative HNSCC. We compared pathologic staging to the 7th and 8th edition AJCC staging systems using a statewide population-based cohort. All M0 p16-negative surgical patients were included. The outcome was five-year overall survival. Of 304 patients identified, 113 were N0, 157 had 1-4 positive nodes, and 34 had ≥4 nodes. Survival was 71% (95% CI 61-78%) with no nodes, 48% (36%-60%) for 1-4 nodes, and 24% (11 - 39%) for>4 nodes. When compared to the AJCC systems, the pathologic staging yielded a larger total survival gradient, more montonic survival, better consistency across primary sites, and a slightly lower Bayesian information criterion (1510 vs 1538). After adjusting for disease characteristics, demographics, and tobacco use, hazard ratios for survival were similar using pathologic and AJCC criteria. In this cohort, pathological staging was more prognostic than AJCC staging. This is the first study to evaluate pathologic staging in p16-negative cancer; if these findings are verified, a universal nodal staging system could be introduced.