Long-term survival after treatment in certified lung cancer centers and not certified hospitals: Results of a large German cohort study using clinical routine data

Lung cancer represents the second most frequent tumor entity worldwide with an increasing number of patients treated in specialized centers. The aim of the WiZen study was to find out whether treatment at hospitals certified by the German Cancer Society (GCS) was associated with long-term survival benefits. Data for this cohort study was derived from the largest German statutory health insurance (SHI) AOK, four regional population-based clinical cancer registries (CCR), and standardized hospital quality reports. The analyses were based on 173,999 incident lung cancer patients in the SHI dataset and 35,702 patients in the CCR dataset who received primary treatment for lung cancer (ICD-10-GM C33, C34, D38.1) between 2009 and 2017. Distributions of age, sex, comorbidities, and most tumor characteristics were similar among patients treated in certified and non-certified hospitals. The Kaplan-Meier estimator for 5-year overall survival was 28.0% for patients from certified and 16.9% from non-certified hospitals (SHI data; CCR data: 21.4% vs. 13.6%). Cox-regression adjusting for relevant confounders yielded hazard ratios of 0.97 (SHI data; 95%CI 0.94, 1.00) and 0.85 (CCR data; 95%CI 0.82, 0.88) for all-cause mortality. The adjusted hazard ratio for recurrence-free survival (CCR data, UICC stage I-III, R0 only) was 0.82 (95%CI 0.75, 0.90). The presented analyses show that treatment in certified lung cancer centers is associated with relevant survival benefits and should therefore be supported.