TNM Staging Does Not Predict Survival in HPV-Positive OPSCC

Abstract

Objective: 1) To establish the rates of HPV associated oropharyngeal SCC (OPSCC) in our local population. 2) To establish the effect of HPV on survival from OPSCC. 3) To establish relevance of TNM staging in OPSCC.

Method: We conducted a retrospective chart review of 256 consecutively treated OPSCCs in Southern England between 2000 and 2010. We recorded TNM stage and other potentially prognostic factors including differentiation, margin status, extracapsular spread, and tumor cohesion. HPV status was determined using both p16 immunohistochemistry and HPV in situ hybridization (ISH).

Results: A total of 57.4% of OPSCC were found to be HPV-positive (p16-positive, ISH-positive) and had improved disease specific survival (DSS) (OR 0.290, P < .001). TNM staging predicted for survival in HPV-negative patients only (HPV-ve OR 2.119, P = .033; HPV+ve OR 2.022, P = .49). Further analysis showed that although T stage was predictive in both cohorts (HPV-ve OR 3.579, P = .006; HPV+ve OR 11.654, P = .001), N stage only predicted for DSS in HPV-negative tumors (HPV-ve OR 1.996, P = .022; HPV+ve OR 1.437, P = .623), despite the fact that a higher proportion of HPV-positive tumors present with advanced nodal disease (N2/N3) (HPV+ve 75.3%, HPV-ve 50.1%, P < .001).

Conclusion: HPV-positive OPSCC frequently presents with advanced nodal disease. However, in contrast to HPV-negative disease, this does not have a negative effect on disease specific survival. These data show that classical prognostic indicators do not apply to HPV-positive OPSCC and highlight the essential requirement for determining HPV status in OPSCC patients.