Symptom Burden Associated With Late Lower Cranial Neuropathy in Long-term Oropharyngeal Cancer Survivors.

Importance: Lower cranial neuropathy (LCNP) is a rare but potentially disabling result of radiotherapy and other head and neck cancer therapies. Survivors who develop late LCNP may experience profound functional impairment, with deficits in swallowing, speech, and voice. Objective: To investigate the association of late LCNP with severity of cancer treatment-related symptoms and subsequent general functional impairment among oropharyngeal cancer (OPC) survivors. Design, Setting, and Participants: This cross-sectional survey study analyzed 889 OPC survivors nested within a retrospective cohort of OPC survivors treated at MD Anderson Cancer Center from January 1, 2000, to December 31, 2013. Eligible survey participants were disease free and completed OPC treatment 1 year or more before the survey. Data analysis was performed from October 10, 2017, to March 15, 2018. Exposures: Late LCNP defined by onset 3 months or more after cancer therapy. Main Outcomes and Measures: The primary outcome variable was the mean of the top 5 most severely scored symptoms of all 22 core and head and neck cancer-specific symptoms from the MD Anderson Symptom Inventory Head and Neck Cancer Module (MDASI-HN). Secondary outcomes included mean MDASI-HN interference scores and single-item scores of the most severe symptoms. Multivariate models regressed MDASI-HN scores on late LCNP status, adjusting for clinical covariates. Results: Overall, 36 of 889 OPC survivors (4.0%) (753 [84.7%] male; 821 [92.4%] white; median [range] age, 56 [32-84] years; median [range] survival time, 7 [1-16] years) developed late LCNP. Late LCNP was significantly associated with worse mean top 5 MDASI-HN symptom scores (coefficient, 1.54; 95% CI, 0.82-2.26), adjusting for age, survival time, sex, therapeutic modality, T stage, subsite, type of radiotherapy, smoking, and normal diet before treatment. Late LCNP was also significantly associated with single-item scores for difficulty swallowing or chewing (coefficient, 2.25; 95% CI, 1.33-3.18), mucus (coefficient, 1.97; 95% CI, 1.03-2.91), fatigue (coefficient, 1.35; 95% CI, 0.40-2.21), choking (coefficient, 1.53; 95% CI, 0.65-2.41), and voice or speech symptoms (coefficient, 2.30; 95% CI, 1.60-3.03) in multivariable models. Late LCNP was not significantly associated with mean interference scores after correction for multiple comparisons (mean interference coefficient, 0.72; 95% CI, 0.09-1.35). Conclusions and Relevance: In this large survey study, OPC survivors with late LCNP reported worse cancer treatment-related symptoms, a finding suggesting an association between late LCNP and symptom burden. This research may inform the development and implementation of strategies for LCNP surveillance and management.