Nationwide retrospective study of association of autoimmune diseases with pancreatic cancer in Sweden

The incidence of pancreatic cancer (PC) and autoimmune diseases (ADs) is increasing worldwide. While certain associations between specific ADs, such as pancreatitis, are well confirmed, population-based research investigating the broader spectrum of ADs and their relationship with PC risk remains limited. A cohort study in Sweden investigated the associations of 43 specific ADs and PC risk. Within the study’s total population of 16.4 million, 1.1 million cases of ADs were identified (1964-2018), and 3257 patients were later diagnosed with PC, accounting for 5.42% of all cancer cases in the cohort. The standardized incidence ratios for PC in patients with ADs were 1.24 (men) and 1.19 (women); 12 ADs were positively correlated with the incidence of PC The standardized mortality ratios for PC in patients with ADs were 1.28 (men) and 1.22 (women); 15 ADs were positively correlated with PC mortality. Among the ADs associated with incidence or mortality of PC were discoid lupus erythematosus, lupoid hepatitis, giant cell arteritis, and rheumatic fever. The authors conclude that these results support the notion that ADs may have a role in the onset of PC.