The regular use of aspirin significantly reduces the overall risk of cancer, according to an analysis led by HMS researchers at Massachusetts General Hospital. Their review of data from two major long-term epidemiologic studies also shows that the reduction primarily reflects a lower risk of colorectal cancer and other tumors of the gastrointestinal tract.
The findings, published online March 3 in JAMA Oncology, suggest that the use of aspirin may complement, but not replace, the preventive benefits of colonoscopy and other methods of cancer screening.
“We now can recommend that many individuals consider taking aspirin to reduce their risk of colorectal cancer—particularly those with other reasons for regular aspirin use, such as heart disease prevention—but we cannot yet make a general recommendation for overall cancer prevention,” says Andrew Chan ’97, an HMS associate professor of medicine at Mass General and senior author of the report.
“Aspirin use may have an even greater benefit in settings in which the resources to devote to cancer screening are lacking,” he adds.
A number of studies have supported regular aspirin use to prevent colorectal cancer, but aspirin’s effect on overall cancer risk hasn’t been clear. To investigate further, the research team analyzed data spanning thirty-two years from almost 136,000 female and male participants in the Nurses’ Health Study and the Health Professionals Follow-up Study.
The scientists found that participants who reported regular aspirin use—taking either a standard or a low-dose aspirin tablet at least twice a week—had a 3 percent absolute lower risk of any type of cancer compared to those not reporting regular aspirin use. Regular aspirin use reduced the risk of colorectal cancer by 19 percent and the risk of any gastrointestinal cancer by 15 percent.
No reduction was seen in the risk of breast, prostate, or lung cancer.
Aspirin’s protective benefit appeared after five years of continuous use at dosages ranging from one-half to one and one-half standard tablets a week or one low-dose tablet a day. The benefit related to other gastrointestinal tumors appeared after six years and at the same dosage level—equivalent to a daily low-dose tablet—that many people take to prevent cardiovascular disease.
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