Ischemic cardiac or cerebrovascular disease (ICCD) survivors represent a subpopulation with a high cancer risk. Antiplatelet medications, such as aspirin, remain a fundamental therapy for the secondary prevention of ischemic attack in these patients. We conducted a population-based cohort study to investigate the association of long-term low-dose aspirin use with the risk of primary cancer in ICCD survivors. Patients aged ≥20 years with newly diagnosed ICCD (n = 98,519) between January 2000 and December 2013 were identified from the Taiwan National Health Insurance Research Database. The aspirin user and nonuser groups (each n = 24,030) were propensity-matched (1:1) for age, sex, comorbidities, prior medications, ICCD diagnosis year, and year of index dates. The incidence rate of primary cancer was significantly lower in the user group (6.49/1000 person-years) than in the nonuser group (14.04/1000 person-years). Multivariate Cox regression analysis indicated that aspirin use was an independent factor associated with a reduced risk of primary cancer (aHR (95% confidence interval) = 0.42 (0.38–0.45)) after adjustment. Kaplan–Meier curve analysis revealed that the cumulative incidence rate of primary cancer was significantly lower (p < 0.0001) in the user group than in the nonuser group over the 14-year follow-up period. Subgroup analyses demonstrated that this anticancer effect increased with duration of treatment and with similar estimates in women and men. In addition, aspirin use was associated with a reduced risk for seven out of the ten most common cancers in Taiwan. These findings suggest the anticancer effect of aspirin in ICCD survivors and provide information for assessing the benefit-to-risk profile of aspirin as an antiplatelet medication in these patients.

Background Aspirin lowered some cancer occurrence rate, through the inhibition of the cyclooxygenase enzyme. The association of aspirin-use and hepatocellular carcinoma (HCC) occurrence rate in hepatitis B virus (HBV) carriers is well known. However, the association in hepatitis C virus (HCV) carriers is not known. Our purpose is comparing the HCC occurrence rate in HCV carriers with or without Aspirin treatment. Methods In this retrospective cohort study, the participants were ones newly-diagnosed with HCV from 2000 to 2012 in Taiwan. These HCV carriers with aspirin treatment were defined as the control group, whereas those without aspirin were defined as a compared cohort. We used a 1:1 propensity score matching by age, sex, comorbidities, drugs, diagnosis year and index year with covariate assessment. Results Our study sample consisted of 2980 aspirin-treated HCV carriers and 7771 non-aspirin-treated HCV carriers. After propensity score matching, each cohort consisted of 1911 HCV carriers. The adjusted hazard ratio (aHR) of HCC incidence in aspirin users (aHR=0.56, 95% CI=0.43-0.72, p < 0.001 ) was significantly lower than that in non-aspirin users. The Kaplan-Meier curves show that among the HCV carriers, aspirin users had a lower cumulative incidence rate of HCC in the first 10-year aspirin treatment course ( p < 0.0001 ). Conclusions The HCC incidence rate was lower in the aspirin users than non- aspirin users among HCV carriers, supporting the aspirin effect may be acting through inhibition of the cyclooxygenase enzyme pathway. Moreover, the patients got HCC protection by aspirin within 1-year treatment course and had best HCC prevention during 1- to 2-year aspirin treatment course. We encourage aspirin treatment to prevent HCC in HCV carriers.