Survival outcomes with concomitant chemoradiotherapy in older adults with oropharyngeal carcinoma in an era of increasing human papillomavirus (HPV) prevalence

Background: Human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has dramatically increased in incidence and prevalence among patients aged 70 and older. There are virtually no data regarding outcomes in this population, and thus optimal therapy, including the role of chemotherapy for those undergoing radiotherapy (RT), remains unclear. Methods: The National Cancer Database was queried for older adults (defined as age 70 years and older) with locally advanced OPSCC (cT1-2N1-3, cT3-4N0-3) diagnosed from 2010 to 2014 with known HPV-status undergoing definitive RT alone or chemoradiation (CRT). Results: Overall, 1,965 older adults with locally advanced OPSCC ma inclusion criteria, including 1,141 HPVpositive (58%) and 824 HPV-negative (42%) patients. 1,211 patients (62%) received CRT. In multivariable analysis, CRT was associated with improved survival in older patients when compared to RT alone (hazard ratio [HR] = 0.74, 95% confidence interval [CI] 0.64-0.86, P < 0.001). CRT was associated with improved survival in both HPV-positive (HR = 0.80, 95% CI: 0.64-1.00, P = 0.05) and HPV-negative (HR = 0.69, 95% CI: 0.56-0.85, P < 0.001) subgroups. There was no significant interaction between HPV status and the impact of CRT on survival (P interaction = 0.57). Conclusions: Despite the radiosensitivity of HPV-positive OPSCC and the challenges in delivering CRT to older adults, CRT was associated with improved survival in older patients with HPV-positive OPSCC, similar in magnitude to the benefit in HPV-negative patients. As the incidence of HPV-positive OPSCC in older patients continues to increase, further studies are needed to investigate optimal therapeutic strategies in this population.