A nationwide population-based cohort study of hospital academic status and survival following colorectal cancer surgery in Finland 1987–2016

There is a lack of evidence regarding hospital academic status and survival following colorectal cancer surgery and there is a paucity of data from European countries. The aim of this study was to investigate this association between hospital academic status and mortality after colon and rectal cancer surgery. All 49 032 patients who underwent resection for colorectal cancer in years 1987-2016 in Finland were included, with complete follow-up until December 31, 2019. Primary outcome was all-cause 5-year mortality. Cox regression provided hazard ratios (HR) with 95% confidence intervals (CI) in academic and non-academic hospitals for colorectal surgery, adjusted for calendar period, age, sex, comorbidity, stage, tumor location and oncological therapy. Additionally, colon and rectal cancer surgery were assessed separately. Total colectomies were included in the study, and the cancer location was based on the first location information that was reported by the cancer registry or in the ICD code if not reported in the cancer registry. The manuscript was written according to Equator network guidelines. Compared to academic hospitals, the patients operated in non-academic hospitals had a slightly increased 5-year all-cause mortality (adjusted HR 1.07, 95% CI 1.04-1.11) and also the 30-day and 90-day mortality was increased in patients operated in non-academic hospitals. Sensitivity analysis including only patients operated with confirmed curative intent suggested no differences between academic and non-academic hospitals in colorectal cancer for 5-year all-cause mortality or in 5-year cancer specific mortality, respectively. In analysis including hospital volume as an explanatory covariate, the increase in 5-year mortality in non-academic hospitals compared to academic hospitals was stronger than in main analysis. A pre-planned subgroup-analysis stratified by cancer type (colon, or rectal) suggested a slightly decreased 5-year all-cause mortality in academic institutions for rectal but not for colon cancer surgery. Hospital academic status is associated with slightly improved 5-year mortality in colorectal cancer surgery, but benefits of centralization to academic hospitals may be limited to rectal cancer surgery.