Aspirin use three or more times per week is associated with reductions in all-cause, any cancer, gastrointestinal cancer, and colorectal cancer (CRC) mortality among older adults, according to a study, ‘With Mortality Risk Among Older Adult Participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial’, published in JAMA Network Open.
Aspirin use has been associated with reduced risk of cancer mortality, particularly of the colorectum. However, aspirin efficacy may be influenced by biological characteristics, such as obesity and age. With the increasing prevalence of obesity and conflicting data regarding the effect of aspirin in older adults, understanding the potential association of aspirin use with cancer mortality according to BMI and age is imperative.
Therefore, Dr Holli A Loomans-Kropp from the National Cancer Institute in Rockville, MD, and colleagues sought to investigate the association of aspirin use with risk of all-cause, any cancer, gastrointestinal (GI) cancer and CRC mortality among older adults (aged 65 years and older) and performed an exploratory analysis of the association of aspirin use with mortality stratified by BMI.
Using data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, they examined records from 146,152 individuals (mean age at baseline, 66.3 years) who were followed for a median of 12.5 years (November 1993 to July 2, 2001 and follow-up 2006-2008), encompassing 1,822,164 person-years. Analysis began in late 2018 and was completed in September 2019.
The primary outcome was all-cause, any cancer, GI cancer,or CRC mortality. The investigators performed multivariable hazard ratios (HRs) and 95% CIs were calculated using time-varying Cox proportional hazards regression modelling, adjusted for additional factors.
The researchers found that aspirin use one to three times per month correlated with a reduced risk for all-cause and cancer mortality compared with no use (hazard ratios, 0.84 and 0.87, respectively). Reduced risks for mortality of all causes, any cancer, gastrointestinal cancer and CRC were reported with aspirin use three or more times per week (hazard ratios, 0.81, 0.85, 0.75, and 0.71, respectively).
On stratification by BMI, aspirin use three or more times per week correlated with a reduced risk for all-cause and any cancer mortality among those with a BMI20-24 (hazard ratios, 0.82 and 0.86, respectively) and with reduced risk for all-cause, any cancer, gastrointestinal cancer and CRC mortality with a BMI25-29.9 (hazard ratios, 0.82, 0.86, 0.72, and 0.66, respectively).
"Future studies should further examine the association of BMI with the efficacy of aspirin as a cancer preventive agent to adapt to the changing global obesity trends," the authors write.
One author disclosed financial ties to the pharmaceutical industry.