The role of aspirin in the prevention of pancreatic cancer: A nested case-control study in the UK Biobank.

Background: Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) usage has been associated with pancreatic ductal adenocarcinoma (PDAC) prevention, though epidemiological data have not reliably demonstrated this. The aim of this study is to identify if aspirin and other NSAIDs are effective in the primary prevention of PDAC in a large UK prospective cohort.

Methods: A nested case-control study was conducted using the UK Biobank cohort. Incident PDAC cases (n = 1129 of whom 239 (21.2 %) were using aspirin) were age and sex-matched with cancer-free controls (n = 8822 of whom 1752 (19.9 %) were using aspirin). Conditional logistic regression models were used to generate odds ratios (ORs) and 95 % confidence intervals (CI) for risk of PDAC with and without regular use of aspirin, non-aspirin NSAIDs and all NSAIDs respectively. Exploratory analyses were carried out assessing interactions with diabetes mellitus (DM) as a condition with increased pancreatic cancer risk.

Results: Regular aspirin use at initial recruitment was independently associated with a decreased risk of PDAC (OR [95 % CI] = 0.80 [0.68-0.95] P = 0.01). Regular non-aspirin NSAID use was not associated with a risk reduction of PDAC (OR [95 % CI] = 1.01 [0.84-1.23] P = 0.88). Exploratory analyses showed that in those with DM; regular aspirin use reduced risk of PDAC (OR [95 % CI] = 0.60 [0.42-0.85] P = 0.004) compared to non-use.

Discussion: Regular aspirin use is associated with a reduction in risk of PDAC. The reduced risk is more apparent in participants with DM.