A retrospective analysis of oropharyngeal patients with recurrence of disease after primary therapy in the Radiation Therapy Oncology Group (RTOG) studies 0129 or 0522 found that HPV-positive patients had a higher overall survival (OS) rate than HPV-negative patients (at two years post-treatment, 54.6 percent vs. 27.6 percent, respectively), according to research presented at the 2014 Multidisciplinary Head and Neck Cancer Symposium.
The analysis included 181 patients with stage III-IV oropharyngeal squamous cell carcinoma (OPSCC) with known HPV status (HPV-positive = 105; HPV-negative = 76), and cancer progression that was local, regional and/or distant after completion of primary cisplatin-based chemotherapy and radiation therapy (standard vs. accelerated fractionation (AFX)) in RTOG 0129 or cisplatin-AFX with or without cetuximab in RTOG 0522. Tumor status was determined by a surrogate, p16 immunohistochemistry.
Median time to progression was virtually the same for HPV-positive and HPV-negative patients (8.2 months vs. 7.3 months, respectively). Increased risk of death in univariate analysis was associated with high tumor stage at diagnosis (T4 vs. T2-T3), fewer on-protocol cisplatin cycles (≤1 vs. 2-3) and distant vs. local/regional recurrent (for all, hazard ratios (HRs) >2.0 and p<0.05). Risk of death after disease progression increased by 1 percent per cigarette pack-year at diagnosis. Rates were estimated by Kaplan-Meier method and compared by log-rank. HRs were estimated by Cox proportional hazards models and stratified by treatment protocol.
In addition, HPV-positive and HPV-negative patients who underwent surgery after cancer recurrence also experienced improved OS compared to those who did not undergo surgery. (The effect may have been more pronounced among HPV-positive than HPV-negative patients.) Recurrence is most commonly in the lungs for both groups of patients.
"Our findings demonstrate that HPV-positive OPSCC patients have significantly improved survival after progression of disease when compared with HPV-negative patients. Median survival after disease progression was strikingly longer for HPV-positive than HPV-negative patients," said lead author Carole Fakhry, MD, MPH, assistant professor in the Department of Otolaryngology Head and Neck Surgery at Johns Hopkins Medicine in Baltimore. "These findings provide us with valuable knowledge to better counsel and treat patients."