Aspirin Use and Risk of Pancreatic Ductal Adenocarcinoma: A Large Case-Control Study

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers, with a five-year survival rate of approximately 5%. The incidence and mortality rates of PDAC are increasing, and the results of medical treatments remain unsatisfactory. Some conflicting evidence suggests that aspirin intake may reduce the risk of PDAC. This study aimed to evaluate the association between regular low-dose aspirin use (80-mg aspirin tablets, 5-7 tablets/week) and the risk of PDAC.

This prospective, hospital-based, case-control study was performed on 470 PDAC patients (case group) and 526 sex and age-matched controls, in Tehran, Iran from 2011 to 2018. The participants were interviewed regarding the patterns of aspirin use. Data are expressed as mean±SD or frequency and percentage as appropriate. Differences in frequency between the case and control groups were evaluated based on the analysis of the contingency table (χ² test and Fisher's exact test). Propensity score models were designed to calculate odds ratios (OR) and 95% confidence intervals (95% CIs) for PDAC with respect to aspirin use, adjusted for age, sex, smoking status, opium use, diabetes mellitus, place of residence, and family history of cancer in first-degree relatives.

About 60% of PDAC patients were male in this study. Also, 25.2% of PDAC patients had a family history of cancer in one of their first-degree relatives, 21.99% were smokers, 13.9% were opium users, and 11.7% had a history of diabetes. Aspirin was used by 22.77% of PDAC patients and 18.25% of the controls. Ever aspirin use (OR: 1.01, 95% CI: 0.89 - 1.14) was not associated with PDAC.

Overall, aspirin use was not associated with a reduced risk of PDAC.