Validation of the eighth edition American Joint Committee on Cancer staging system for human papillomavirus-associated oropharyngeal cancer

Abstract

Background: The eighth edition American Joint Committee on Cancer (AJCC) staging manual includes major changes in staging of oropharyngeal cancer (OPC). We evaluated the new staging system in order to validate this shift in classification. Methods: We used the National Cancer Database (NCDB) to identify patients with human papillomavirus-associated (HPV-positive) OPC from 2010-2013. We restaged patients using the eighth edition guidelines and compared them with those from the seventh edition. We calculated stage-specific overall survival and concordance indices. Results: We identified 15 116 patients with a median follow-up period of 29.1 months. Clinical and pathological staging changed for 93.9% and 91.7% of patients, respectively. Survival concordance indices for both clinical (0.621-0.656) and pathological (0.640-0.663) staging were improved in the eighth edition compared to the seventh edition. Conclusion: The eighth edition guidelines have profoundly altered staging of HPV-positive OPC and seem to demonstrate improved survival discrimination.