Sleep-related symptoms are associated with survival in oropharyngeal cancer radiotherapy survivors: Temporal characterization of patient-reported outcomes in a large-scale prospective longitudinal cohort.

PURPOSE: Sleep-related symptoms in head and neck cancer are poorly characterized and often under-recognized. We examined symptom trajectories, prevalence of moderate/severe symptoms, and associations between severe sleep-related patient-reported symptoms and overall survival (OS) in oropharyngeal cancer (OPC) patients receiving radiotherapy (RT). METHODS: This retrospective analysis included a longitudinal cohort of 372 patients with OPC treated with curative-intent RT (± chemotherapy) at a tertiary center. Symptoms were assessed at the earliest available pre-RT baseline, RT start, RT end, and 6 months post-RT using the MD Anderson Symptom Inventory-Head and Neck (MDASI-HN). The sleep-related symptom domains were fatigue, sleep disturbance, and drowsiness. OS was evaluated using Kaplan-Meier and multivariable Cox models. RESULTS: Severe fatigue, sleep disturbance, and drowsiness were infrequent at baseline but peaked at RT end (26%, 15%, and 18%, respectively) and returned to near-baseline levels by 6 months (6%, 4%, and 2%). Severe longitudinal fatigue (HR 5.05), sleep disturbance (HR 3.86), and drowsiness (HR 8.24) were independently associated with worse OS. Severe symptoms at RT start were also associated with worse OS (fatigue HR 3.58; sleep disturbance HR 5.08; drowsiness HR 7.76; all p < 0.05). Aside from age, severe average daily symptom scores and severe symptoms at RT start were associated with OS after multivariable adjustment. CONCLUSION: Severe sleep-related symptoms peaked during RT. Severe fatigue, sleep disturbance, and drowsiness, both longitudinally and at RT start, were associated with worse OS. These observational associations do not establish causality; symptom assessment may help identify patients who warrant supportive evaluation.