Panacreatic cancer risk after benign gallbladder disease: A Swedish population-based cohort study

Aim

The purpose of this nationwide registry-based cohort study was to outline pancreatic cancer risk after benign gallbladder disease (GBD). Anatomically adjacent cancers were investigated to address incidental findings.

Methods

We included all Swedes aged 20–79 years with histologically confirmed GBD (cholecystitis and/or cholecystectomy) in 1992–2016 and five matched non-exposed population comparators. Follow-up started one month after GBD and incidence rates (IR) and hazard ratios (HR) with 95 % confidence intervals (CI) up to 15 years after GBD were estimated using Poisson and Cox regression, respectively. Fully adjusted models included sex, age, year, education, type 2 diabetes, obesity, smoking-, and alcohol-related disorders. Analyses were stratified by follow-up and flexible parametric models applied to assess time-varying effects. Interaction models were used to identify patient groups at risk.

Results

680 and 1890 incident pancreatic cancers were detected over 15 years in 130907 GBD exposed and 571618 non-exposed, respectively. An excess pancreatic cancer risk was mainly seen within the first 2 years; IR: 84 [95 % CI 73,95] versus 31 [95 % CI 27,34] per 100000 person-years corresponding to an HR of 2.74 [95 % CI 2.31,3.25]. The same pattern was noted for duodenal cancer while primary liver cancer risk was elevated across follow-up. An initial extrahepatic biliary cancer risk elevation shifted to a reduction over time. The 2-year pancreatic cancer risk was augmented in younger (age 20–49) individuals, HR 7.64 [95 % CI 3.73,15.65].

Conclusion

Our findings urge more studies on the clinical follow-up the first years after cholecystitis to detect early pancreatic cancer.