Association of Aspirin Use with Mortality Risk Among Older Adult Participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Loomans-Kropp HA1, Pinsky P, Cao Y, Chan AT, Umar A. JAMA Netw Open. 2019 Dec 2;2(12):e1916729. [CrossRef] [PubMed]

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, the authors evaluated aspirin use among participants aged 65 years and older in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial at baseline (November 8, 1993, to July 2, 2001) and follow-up (2006-2008). The majority endpoints were all-cause, any cancer, GI cancer, or colorectal cancer (CRC) mortality. Multivariable hazard ratios (HRs) and 95% CIs were calculated using time-varying Cox proportional hazards regression modeling, adjusting for additional factors. Compared with no use, aspirin use 1 to 3 times per month was associated with reduced risk of all-cause mortality (HR, 0.84; 95% CI, 0.80-0.88; P < .001) and cancer mortality (HR, 0.87; 95% CI, 0.81-0.94; P < .001). Aspirin use 3 or more times per week was associated with decreased risk of mortality of all causes (HR, 0.81; 95% CI, 0.80-0.83; P < .001), any cancer (HR, 0.85; 95% CI, 0.81-0.88; P < .001), GI cancer (HR, 0.75; 95% CI, 0.66-0.84; P < .001), and CRC (HR, 0.71; 95% CI, 0.61-0.84; P < .001). When stratified by BMI (calculated as weight in kilograms divided by height in meters squared), aspirin use 3 or more times per week among individuals with BMI 20 to 24.9 was associated with reduced risk of all-cause mortality (HR, 0.82; 95% CI, 0.78-0.85; P < .001) and any cancer mortality (HR, 0.86; 95% CI, 0.79-0.82; P < .001). Among individuals with BMI 25 to 29.9, aspirin use 3 or more times per week was associated with reduced risk of all-cause mortality (HR, 0.82; 95% CI, 0.79-0.85; P < .001), any cancer mortality (HR, 0.86; 95% CI, 0.81-0.91; P < .001), GI cancer mortality (HR, 0.72; 95% CI, 0.60-0.86; P < .001), and CRC mortality (HR, 0.66; 95% CI, 0.51-0.85; P = .001). The authors conclude that aspirin use 3 or more times per week was associated with a reduction in all-cause, cancer, GI cancer and CRC mortality in older adults.