Low-dose aspirin has not been proven to reduce cancer incidence in adults with type 2 diabetes but it might be beneficial for cancer chemoprevention in patients younger than 65 years, according to a 10-year follow-up cohort study published in Diabetes Care.
The study was a post hoc assessment of a randomized controlled trial that ended in 2008 and included 2536 Japanese patients aged 30 to 58 years with type 2 diabetes and without preexisting cardiovascular disease. In the initial trial, researchers sought to determine the long-term efficacy of using low-dose aspirin to lower the risk for cancer in patients with diabetes.
Patients were randomly assigned to either receive aspirin (81 or 100 mg daily) or no aspirin. During the follow-up period (median 10.7 years), the researchers discovered no significant difference in total cancer incidence. There were 318 cancer events: 149 in the aspirin group and 169 in the non-aspirin group (P =.4).
Cancer incidence results for the aspirin group were separated into subgroups. Further scrutiny showed that low-dose aspirin did not affect men or women significantly, and there was no difference in cancer incidence for patients aged ≥65 years.
However, through the use of hazard models that adjusted for sex, smoking status, and the administration of metformin and statins, aspirin was found to decrease cancer incidence substantially overall in patients aged <65 years (P =.04).
As a secondary outcome, the researchers discovered no difference between the total cancer mortality rate of the aspirin and non-aspirin groups (P <.6).
The researchers highlighted certain limitations to their follow-up study, including an inability to generalize findings to other populations because of lifestyle and racial differences.
“Although recent guidelines were revised to deemphasize the use of low-dose aspirin for primary prevention of cardiovascular disease in patients with diabetes,” researchers said, “cumulative evidence suggests the benefit of administering low-dose aspirin for cancer chemoprevention in [the Japanese] population.”
Okada S, Morimoto T, Ogawa H, et al; for the JPAD Trial Investigators. Effect of aspirin on cancer chemoprevention in Japanese patients with type 2 diabetes: 10-year observational follow-up of a randomized controlled trial [published online June 16, 2018]. Diabetes Care. doi: 10.2337/dc18-0368