Implications of updated staging system for p16+ oropharyngeal squamous cell carcinoma: Is valuable prognostic information being omitted?

Abstract

This study characterized whether the updated AJCC 8th edition nodal staging system for p16+ oropharyngeal squamous cell carcinoma (OPSCC) resulted in the loss of prognostic value. The NCDB was queried for patients with node-positive p16+ OPSCC. The prognostic impact of nodal size, nodal quantity, nodal laterality, and extracapsular extension (ECE) on overall survival (OS) was assessed. In the clinical cohort, inferior 5-year OS was observed in patients with more than one positive lymph node (p < 0.001; 82% vs. 86%), ECE (p < 0.001; 82% vs. 75%), or nodal size >6 cm (p < 0.001; 66% vs. 82%). In the pathologic cohort, inferior 5-year OS was observed in patients with > four positive lymph nodes (p < 0.001; 76% vs. 90%), ECE (p < 0.001; 83% vs. 92%), or largest nodal size >6 cm (p < 0.001; 81% vs. 89%). Simplifications in the current p16+ OPSCC staging system led to loss of prognostic information in nodal staging.