Utilizing the AJCC 8th Staging to Discriminate Survival Outcomes in HPV-associated Oropharyngeal Squamous Cell Carcinoma.

Abstract

The American Joint Committee on Cancer (AJCC) staging 8th edition introduced major changes in the TNM staging of oropharyngeal squamous cell carcinoma (OPSCC) based on the human papillomavirus (HPV) status. This study aimed to observe how well the AJCC staging 8th edition precisely discriminates survival outcomes in patients with HPV-associated OPSCC using a large population database. Using the Surveillance, Epidemiology, and End Results database between 2010 and 2016, 7,448 patients with HPV-associated OPSCC were enrolled. Patients diagnosed with OPSCC and tested positive for HPV with information on the TNM staging according to the AJCC staging 7th edition were selected. Next, T-, N-, and clinical staging were reconstructed based on the AJCC staging 8th edition. Survival probabilities in both AJCC staging 7th and 8th editions were estimated and compared. Most patients (93.44%) were down-staged from the 7th to the 8th edition. The AJCC staging 8th edition showed more discriminatory power in predicting survival of patients with HPV-associated OPSCC than the AJCC staging 7th edition, regardless of the primary subsites. Additionally, clinical stage I patients with HPV-associated OPSCC according to the AJCC 8th edition showed better prognosis in case of high T staging than high N staging. Clinical staging according to the AJCC 8th edition compared to that of the 7th edition was an independent prognostic factor in patients with HPV-associated OPSCC. This study emphasizes the advantages of the new classification system for discriminating survival in HPV-associated OPSCC according to various factors.