Toxicity and Outcomes of Definitive Local Therapy in Elderly Patients with HPV-Associated Oropharyngeal Cancer

Abstract

The incidence of human papillomavirus (HPV) associated oropharyngeal squamous cell carcinoma (HPV-OPSCC) has increased in elderly patients. It is unclear if survival outcomes in elderly patients are similar to those seen in younger patients with HPV-OPSCC. In this study we evaluated disease outcomes and toxicity in an elderly HPV-OPSCC population treated with curative-intent treatment of radiotherapy with or without chemotherapy. We performed a retrospective study of elderly patients (≥70 years old) with HPV-OPSCC treated between 2011-2021 with radiation therapy (RT) with or without chemotherapy. Time to event analysis for overall survival (OS), local control, and progression free survival (PFS) were estimated using the Kaplan-Meier method. Univariate and multivariate Cox regression models were used to estimate the hazard ratio associated with the covariates. We identified 77 elderly HPV-OPSCC patients, of which 60 (78%) were treated with concurrent chemotherapy. Twenty (26%) received concurrent Carboplatin and Taxol, 16 (21%) received Cetuximab, 14 (18%) received Cisplatin,7 (9%) received Carboplatin alone, and 2 (2%) received immunotherapy (Pembrolizumab or Nivolumab). The majority of patients received a radiation dose of 69.96 Gy or 70 Gy (89%). Forty-seven patients (61%) were stage I, 11 (14%) were stage II, 16 (21%) were Stage III, and 3 (4%) had stage IV disease. 50 patients (64%) were former smokers, 27 (35%) were nonsmokers and 1 (1%) is a current smoker. 37 patients (48%) had a ≥10 pack year smoking history. The 5-year OS, LC, and PFS for the entire cohort was 61%, 94%, and 58%, respectively. On univariate analysis, ECOG performance status (HR 0.22, [CI 0.06-0.78], p = 0.019) and Charlson Comorbidity Index (CCI) (HR 1.33, [CI 1.06-1.69], p = 0.014) were significant predictors of OS. On multivariate analysis, only CCI (HR 1.34, [CI 1.02-1.77], p = 0.035) was a significant predictor of OS. The rate of long-term feeding tube dependency was 9%. Late toxicities include osteoradionecrosis in 4 patients (5%), aspiration in 3 patients (4%), and esophageal stricture in 2 patients (3%). Elderly HPV-OPSCC patients treated with definitive intent radiotherapy with or without chemotherapy have favorable disease outcomes with low rates of late toxicity. The Charlson-Comorbidity Index can identify a subset of patients who may have a prolonged OS, and therefore may benefit from more aggressive treatment.