Objective
The goal of this study is to evaluate patterns of failure and survival in relation to HPV/p16 status in patients with oropharyngeal (OP) cancers who were treated with chemoradiotherapy.
Methods
A retrospective review of 271 consecutive head and neck cancer patients with known HPV/p16 status treated between 2009 and 2012 were reviewed. Ninety-four were identified OP cancers. Ninety-five percent of patients were treated with intensity-modulated radiation therapy (IMRT) with or without systemic therapy. Diagnostic imaging was coregistered with the planning CT scan in order to assess radiation dose statistics for the failure site.
Results
The median follow-up time was 30 months. The estimated 3-year overall survival for the cohort was 63 %. There was a trend for improved survival in HPV/p16+ patients compared to HPV/p16− patients (75 vs 58 %, p = 0.052). Heavy smoking was related to worse survival. There was a nonsignificant increase in locoregional failure (15.4 vs 2.8 %, p = 0.127) and distant metastasis (12.5 vs 1.5 %, p = 0.108) in HPV/p16− compared to HPV/p16+ tumors. No neck failures occurred in the HPV/p16+ patients, while six neck failures occurred in HPV/p16− patients. There was no difference between elective nodal doses between the two groups. A lower mean elective nodal dose was significant for predicting neck failure (44.54Gy vs 55.19Gy, p = 0.042).
Conclusion
HPV/p16− patients have trends toward worse overall survival, locoregional recurrence, and distant metastasis. Lower elective nodal doses in HPV/p16− patients may increase the risk for elective neck failure.