Prognostic significance of the AJCC staging in patients with squamous cell carcinoma of the oropharynx.

Abstract

5529 Background: There have been significant changes in the epidemiology of head and neck squamous cell carcinomas (HNSCC), with an increase in the incidence of oropharyngeal (OP) cancer and opposite effect in other sites. Since the rise in OP cancer incidence is attributed to human papillomavirus (HPV), which is associated with a different biology and clinical behavior, we evaluated whether the current AJCC system retained its prognostic impact in this patient population. Methods: The Surveillance Epidemiology and End Results (SEER) registry was queried for patients with HNSCC diagnosed between 2004 and 2007. Overall survival (OS) was estimated by the Kaplan-Meier method and the Cox model was used to compare the survival curves for each AJCC stage. Patients were grouped into three anatomical locations: oral cavity (OC), larynx (L) and OP. Results: There were 26,520 patients meeting eligibility criteria, including 8622 OP, 7332 OC, and 10566 L. The AJCC staging retained its prognostic significance across all stages for patients with HNSCC of the OC and L. Patients with OP cancer, however, had similar 4-year survival for stages I through IVA, whereas stage IVB and IVC had a significantly decrease survival compared to IVA and IVB respectively (Table). Conclusions: The OS for stages III and IVA OP cancer is similar to those with stages I and II, in an effect that may be attributed to the increased frequency of HPV in this population, rendering the tumors more sensitive to chemotherapy and radiation. Therefore, the AJCC stage in OP cancer may be more useful in guiding the therapy than as a prognostic factor. [Table: see text]