Urban versus rural residency and pancreatic cancer survival: A Danish nationwide population-based cohort study

It is unknown whether urban versus rural residency affects pancreatic cancer survival in a universal tax-financed healthcare system. We conducted a nationwide, population-based cohort study of all patients diagnosed with pancreatic cancer in Denmark from 2004-2015. We used nationwide registries to collect information on characteristics, comorbidity, cancer-directed treatment, and vital status. We followed the patients from pancreatic cancer diagnosis until death, emigration, or 1 October 2017, whichever occurred first. We truncated at five years of follow up. We stratified patients into calendar periods according to year of diagnosis (2004-2007, 2008-2011, and 2012-2015). We used Cox proportional hazards model to compute hazard ratios (HRs) with associated 95% confidence intervals (CIs) of death, comparing patients in urban and rural areas. HRs were adjusted for age, sex, comorbidity, tumor stage, and localization. In a sub-analysis, we also adjusted for cancer-directed treatment. We included 10,594 patients diagnosed with pancreatic cancer. Median age was 71 years (inter-quartile range: 63-78 years), and half were men. The majority (61.7%) lived in an urban area at the time of diagnosis. When adjusting for potential confounders, we observed a better survival rate among pancreatic cancer patients residing in urban areas compared with rural areas (adjusted HR: 0.92; 95% CI: 0.87-0.98). When taking treatment into account, the association was unclear (adjusted HR: 0.96; 95% CI: 0.88-1.04). Pancreatic cancer patients residing in urban areas had a slightly better survival rate compared with patients in rural areas.