Abstract
BackgroundWhether aspirin use can decrease or increase cancer risk remains controversial. In this study, a meta-analysis of cohort studies and randomized controlled trials (RCTs) were conducted to evaluate the effect of aspirin use on common cancer risk.MethodMedline and Embase databases were searched to identify relevant studies. Meta-analyses of cohort studies and RCTs were performed to assess the effect of aspirin use on the risk of colorectal, gastric, breast, prostate and lung cancer. Cochran Q test and the I square metric were calculated to detect potential heterogeneity among studies. Subgroup meta-analyses according to exposure categories (frequency and duration) and timing of aspirin use (whether aspirin was used before and after cancer diagnosis) were also performed. A dose-response analysis was carried out to evaluate and quantify the association between aspirin dose and cancer risk.ResultsA total of 88 cohort studies and seven RCTs were included in the final analysis. Meta-analyses of cohort studies revealed that regular aspirin use reduced the risk of colorectal cancer (CRC) (RR=0.85, 95%CI: 0.78-0.92), gastric cancer (RR=0.67, 95%CI: 0.52-0.87), breast cancer (RR=0.93, 95%CI: 0.87-0.99) and prostate cancer (RR=0.92, 95%CI: 0.86-0.98), but showed no association with lung cancer risk. Additionally, meta-analyses of RCTs showed that aspirin use had a protective effect on CRC risk (OR=0.74, 95%CI: 0.56-0.97). When combining evidence from meta-analyses of cohorts and RCTs, consistent evidence was found for the protective effect of aspirin use on CRC risk. Subgroup analysis showed that high frequency aspirin use was associated with increased lung cancer risk (RR=1.05, 95%CI: 1.01-1.09). Dose-response analysis revealed that high-dose aspirin use may increase prostate cancer risk.ConclusionsThis study provides evidence for low-dose aspirin use for the prevention of CRC, but not other common cancers. High frequency or high dose use of aspirin should be prescribed with caution because of their associations with increased lung and prostate cancer risk, respectively. Further studies are warranted to validate these findings and to find the minimum effective dose required for cancer prevention.
Highlights
Cancer is one of the leading causes of death around the world, with approximately one in six deaths resulting from cancers [1]
88 cohort studies summarized the associations of aspirin use with eight cancer outcomes (CRC incidence/mortality, gastric cancer incidence, breast cancer incidence/mortality, prostate cancer incidence/ mortality and lung cancer incidence), and seven randomized controlled trials (RCTs) examined the effect of aspirin use on nine cancer outcomes (CRC incidence/mortality, gastric cancer incidence/mortality, breast cancer incidence, prostate cancer incidence/mortality and lung cancer incidence/mortality)
The overall effects of aspirin use on cancer outcomes are summarized in Tables 1, 2 and main characteristics of included studies are presented in Supplementary Tables 2, 3
Summary
Cancer is one of the leading causes of death around the world, with approximately one in six deaths resulting from cancers [1]. The most common cancers that occur in men or women include breast, lung, colorectal, gastric and prostate cancer, contributing about 50% of the total number of new cases diagnosed each year [3]. In analyses that included six trials of daily lowdose aspirin in primary prevention, aspirin treatment was found to be associated with an approximately 20% reduction in overall cancer incidence between 3 years and 5 years after initiation of the intervention and a 30% reduction during follow up >5 years. In 2016, the U.S Preventive Services Task Force (USPSTF) has issued a clinical recommendation that a routine use of low-dose aspirin for the primary prevention of CVDs in the elderly is likely to yield substantial additional benefits with regard to CRC prevention, reflecting the accumulating evidence for a chemopreventive effect of low-dose aspirin against cancer [11]. A meta-analysis of cohort studies and randomized controlled trials (RCTs) were conducted to evaluate the effect of aspirin use on common cancer risk
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
