Tumor human papillomavirus (HPV) status is confirmed as a strong and independent prognostic factor for survival of patients with oropharyngeal cancer, report investigators for a large phase III trial established by the Radiation Therapy Oncology Group. Results were presented at the 44th annual meeting of the American Society of Clinical Oncology (ASCO abstract 5510) and published in the New England Journal of Medicine on June 7. Investigators performed a retrospective analysis of the association between tumor HPV status and survival among 323 patients with stage III or IV oropharyngeal squamous cell carcinoma who were enrolled in a randomized trial comparing cisplatin therapy combined with either accelerated- or standard-fractionation radiotherapy. Risk of death among patients with HPV-positive vs HPV-negative cancer was compared using a proportional-hazards model.
In the study, 206 patients had HPV-positive tumors and 117 were HPV-negative. The 3-year overall survival rate for patients with HPV-positive tumors was 82.4%, vs 57.1% with HPV-negative cancer. Progression-free survival rates were 73.7% vs 43.4%, respectively. Following adjustment for other significant determinants of survival (patient age, race, tumor and nodal stage, tobacco use), patients with HPV-positive cancer had a 58% reduction in risk of death relative to patients with HPV-negative tumors. Results will enable stratification of patients into clinical trials by low, intermediate, or high risk of death as determined by HPV status, tobacco use, and cancer stage. Head and neck cancer rates have declined in the past 30 years, but HPV-positive oropharyngeal cancer is rising, with nearly 70% of oropharynx cancer cases determined to be HPV-positive.