Despite its side-effects, primarily bleeding problems, aspirin has been reported to have many health benefits. A new study has found that long-term aspirin use can risk one’s overall risk of cancer. The findings were published online on March 3 in the journal JAMA Oncology.
The study authors note that the US Preventive Services Task Force recently recommended the use of aspirin to prevent colorectal cancer and cardiovascular disease among US adults. However, the association of aspirin use with the risk for other cancer types and the potential population-wide effect of aspirin use on cancer, particularly within the context of screening, remains uncertain. Therefore, they conducted a study to assess the potential benefits of aspirin use for overall and specific types of cancer prevention at a range of doses and durations of use and to estimate the absolute benefit of aspirin in the framework of screening.
For the study, the researchers accessed data from two large US prospective (forward-looking) studies: the Nurses’ Health Study (1980-2010) and Health Professionals Follow-up Study (1986-2012). A total of 135,965 healthcare professionals (88,084 women and 47,881 men) reported on aspirin use biennially (twice a year). The women were aged 30 to 55 years at enrollment in 1976; the men were aged 40 to 75 years in 1986. Final follow-up was completed on June 30, 2012, for the Nurses’ Health Study group and January 31, 2010, for the Health Professionals Follow-up Study group. Data were accessed from September 15, 2014, to December 17, 2015.
The researchers found that among the 88,084 women and 47,881 men who underwent follow-up for as long as 32 years, 20,414 cancers among women and 7,571 cancers among men occurred. Compared to nonregular use, regular aspirin use was associated with a lower risk for overall cancer (3% lower risk), which was primarily due to a lower incidence of gastrointestinal tract cancers (15% reduced risk), especially colorectal cancers (19% reduced risk). The benefit of aspirin on gastrointestinal tract cancers was clear with the use of at least 0.5 to 1.5 standard aspirin tablets per week; the minimum duration of regular use associated with a lower risk was six years. Among individuals older than 50 years, regular aspirin use could prevent 33 colorectal cancers per 100 000 person-years among those who had not undergone a lower endoscopy (colonoscopy) and 18 colorectal cancers per 100,000 person-years among those who had. Regular aspirin use was not associated with the risk for breast, advanced prostate, or lung cancer.
The authors concluded that long-term aspirin use was associated with a modest but significantly reduced risk for overall cancer, especially gastrointestinal tract cancers. They noted that regular aspirin use may prevent a substantial proportion of colorectal cancers and complement the benefits of screening.
The researchers are affiliated with: Harvard T. H. Chan School of Public Health, Boston, Massachusetts; Massachusetts General Hospital and Harvard Medical School, Boston; Harvard Medical School, Boston; Dana-Farber Cancer Institute; and Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts.