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

OBJECTIVES: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. MATERIALS AND METHODS: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. RESULTS: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. CONCLUSION: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.