The use of aspirin 3 or more times a week was associated with a reduction in all-cause, cancer, gastrointestinal (GI) cancer, and colorectal cancer (CRC) mortality in adults 65 and over, according to a study published in JAMA Network Open.
The cohort study evaluated aspirin use in 146,152 individuals, aged 65 and older from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. The authors found that aspirin use 3 or more times per week showed association 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 the data was sorted by body mass index (BMI), individuals with BMI of 20 to 24.9 and aspirin use of 3 or more times per week showed a 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). Participants with BMI 25 to 29.9 and aspirin use 3 or more times per week was showed 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).
“Our exploratory analyses investigating the potential associations among aspirin use, BMI, and mortality risk suggest that the efficacy of aspirin as a cancer preventive agent may be associated with BMI. Participants in the PLCO Cancer Screening Trial who were underweight (ie, BMI <20) had no observable benefit associated with aspirin use.”
For the 146,152 individuals that were evaluated, the mean age at baseline was 66.3 years. The mean duration from baseline to completion of the standard questionnaire was 9.1 years. A total of 40,419 individuals (27.7%) died during follow-up. Of those 12,421 individuals (30.7%) died of any cancer.
The authors noted several limitations to the study, most notably that the study was a secondary analysis of a screening trial with self-reported data on aspirin use. As regular aspirin use was not explicitly defined in the baseline questionnaire, differing interpretation by the participants may have affected how they categorized their individual use.
The authors called for further studies examining the association of BMI with the efficacy of aspirin as a preventive agent for cancer in order to further confirm the findings from the study, noting that changing global obesity trends may substantially alter the population-based efficacy of cancer prevention prophylactics.”
Loomans-Kropp, HA, Pinsky P, Cao Y, Chan AT, Umar A. Association of Aspirin use with Mortality Risk Among Older Adult Participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. JAMA Netw Open. 2019;2(12): e1916729. doi:https://doi.org/10.1001/jamanetworkopen.2019.16729