Aspirin may accelerate cancer progression in older individuals
Aspirin may accelerate the progression of cancer among older people, according to results of a randomized study published in Journal of the National Cancer Institute.
“We conducted this study as a more detailed examination of the effect of aspirin on the development of cancer, as well as death [due to] cancer,” Andrew T. Chan, MD, MPH, chief of the clinical and translational epidemiology unit at Massachusetts General Hospital and professor of medicine at Harvard Medical School, said in a press release. “Deaths were particularly high among those on aspirin who were diagnosed with advanced solid cancers, suggesting a possible adverse effect of aspirin on the growth of cancers once they have already developed in older adults.”
The Aspirin in Reducing Events in the Elderly (ASPREE) trial previously showed an association between use of daily aspirin dosed at 100 mg and an increase in all-cause mortality, primarily due to cancer, among older adults. Other randomized controlled trials, mainly examining younger individuals, showed a delayed cancer benefit with aspirin.
Chan and colleagues conducted a deeper analysis of the impact of aspirin use on cancer incidence and mortality among 19,114 Australian and U.S. community-dwelling ASPREE participants aged 70 years or older (or 65 years and older for U.S. minorities) without cardiovascular disease, dementia or physical disability.
Participants had been randomly assigned to receive low-dose (100 mg) aspirin daily (n = 9,525) or matching placebo (n = 9,589) and were followed for a median 4.7 years.
Fatal and nonfatal cancer events — adjudicated based on clinical records — served as a prespecified secondary endpoint.
Results showed 981 cancer events in the aspirin group and 952 events in the placebo group, with no statistically significant difference between groups for all incident cancers (HR = 1.04; 95% CI, 0.95-1.14), hematological cancer (HR = 0.98; 95% CI, 0.73-1.3) or all solid cancers (HR = 1.05; 95% CI, 0.95-1.15), including by specific tumor type.
However, aspirin appeared associated with increased risk for incident cancer that metastasized (HR = 1.19; 95% CI, 1-1.43) or was stage IV at diagnosis (HR = 1.22; 95% CI, 1.02-1.45). Researchers also observed associations between aspirin use and higher risk for death due to cancers that presented at stage III (HR = 2.11; 95% CI, 1.03-4.33) or stage IV (HR = 1.31; 95% CI, 1.04-1.64).
“We previously reported that amongst older adults taking low-dose aspirin for primary prevention in the ASPREE [trial], there was an increased mortality rate, largely attributed to a higher death rate [due to] cancer,” Chan and colleagues wrote. “In this paper, we provide a more detailed assessment of the cancer incidence and mortality from cancer amongst the major cancer subtypes according to stage of disease at presentation, to help provide a better understanding of the mortality findings. Essentially, [although] the incidence of new localized cancer was similar in those randomized to aspirin or placebo, the number of individuals diagnosed with malignancy at an advanced stage (including those with metastatic cancer at diagnosis), was higher in the aspirin group.”
The unexpected and unexplained results of ASPREE suggest that a critical piece of the puzzle still may be missing in understanding aspirin’s biologic effects on cancer development and evolution among individuals of various ages, according to an accompanying editorial by The University of Texas MD Anderson Cancer Center’s cancer prevention and population sciences vice president and division head, Ernest T. Hawk, MD, MPH, and its program director, Karen Colbert Maresso, MPH.
“Careful post-trial follow-up of the ASPREE participants is warranted, as are mechanistic studies to better understand how aspirin’s effects on cancer development could differ so profoundly by age,” Hawk and Maresso wrote. “Results of the ASPREE trial to date underscore the growing importance of more precise preventive strategies that better align an individual’s molecular risks with specific interventions that mitigate them.”
References
- Hawk ET and Maresso KC. J Natl Cancer Inst. 2020;doi:10.1093/jnci/djaa115.
- McNeil JJ, et al. J Natl Cancer Inst. 2020;doi:10.1093/jnci/djaa114.
Collapse