Prevalence and outcome of central airway obstruction in patients with lung cancer

Introduction Central airway obstruction (CAO) is a life-threatening complication of lung cancer. The prevalence of CAO in lung cancer patients is unknown. We audited CAO burden to inform our local cancer service. Methods This is a cohort review of all new lung cancer diagnoses between 1 November 2014 and 30 November 2015. CAO was defined by CT appearance. CT scans and routine patient records were followed up to 30 November 2018 to determine the prevalence of CAO at diagnosis; the characteristics of patients with prevalent CAO; mortality (using survival analysis); and incident CAO over follow-up. Results Of 342 new lung cancer diagnoses, CAO prevalence was 13% (95% CI 10% to 17%; n=45/342). Dedicated CT scan review identified missed CAO in 14/45 (31%) cases. In patients with prevalent CAO, 27/44 (61%) had a performance status of ≤2, 23/45 (51%) were diagnosed during an acute admission and 36/44 (82%) reported symptoms. Treatments were offered to 32/45 (71%); therapeutic bronchoscopy was performed in only 8/31 (26%) eligible patients. Median survival of patients with prevalent CAO was 94 (IQR 33-274) days. Multivariate analysis, adjusting for age, gender and disease stage, found CAO on index CT scan was independently associated with an increased hazard of death (adjusted HR 1.78 (95% CI 1.27 to 2.48); p=0.001). In total, 15/297 (5%) developed CAO during follow-up (median onset 340 (IQR 114-551) days). Over the audit period, 60/342 (18%; 95% CI 14% to 22%) had or developed CAO. Discussions This is the first description of CAO prevalence in 40 years. Patients with prevalent CAO had a higher mortality. Our data provide a benchmark for service planning.