Impact of active smoking on outcomes in HPV+ oropharyngeal cancer.

Background The role of smoking among patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) is unclear. Methods A retrospective cohort study of patients with HPV(+) OPSCC from 2001 to 2015 at a tertiary-care institution was conducted. The primary outcome was overall survival (OS). Results Among 484 included patients, 94 (19.4%) were active smokers, 226 (46.7%) were former smokers, and 164 (33.9%) never smoked. Among active smokers, 82 patients (87.2%) had a >= 10 pack-year and 69 (73.4%) had a >= 20 pack-year smoking history. After adjusting for covariates, active smoking was a significant predictor of inferior OS (HR 2.28, P < .001) and PFS (HR 2.26, P < .001). When including pack-years as the covariate, >= 20 pack-years predicted a decreased effect-size for inferior OS and PFS. Conclusions For patients with HPV(+) OPSCC, active smoking at diagnosis is the most powerful covariate capturing smoking history to predict OS and PFS.