Colorectal cancer is a significant health concern in the United States, ranking as the second-leading cause of cancer death according to the National Cancer Institute. While the U.S. Preventive Services Task Force previously recommended daily low-dose aspirin to prevent cardiovascular events and colorectal cancer in adults ages 50 to 59, concerns about gastrointestinal bleeding led to the withdrawal of this recommendation in 2016. However, a recent study led by researchers at Harvard-affiliated Mass General Brigham suggests that regular aspirin use may still play a role in reducing the risk of colorectal cancer, especially in individuals with greater lifestyle-related risk factors for the disease.
The study, published in JAMA Oncology, followed more than 100,000 men and women for 30 years to assess the impact of regular aspirin use on colorectal cancer rates. Researchers found that those with less-healthy lifestyles benefited the most from regular aspirin use. Regular aspirin use was defined as either two or more standard-dose (325 mg) tablets per week or daily low-dose (81 mg) aspirin. Study participants were followed from an average age of 49.4 years, and those who regularly took aspirin had a lower 10-year cumulative incidence of colorectal cancer compared to those who did not take aspirin.
Interestingly, the benefit of aspirin was most significant in individuals with the unhealthiest lifestyles. Those with the least-healthy lifestyle scores had a higher chance of developing colorectal cancer if they did not take regular aspirin, but this risk was reduced in those who took aspirin regularly. Lifestyle scores were calculated based on factors such as body mass index, frequency of cigarette and alcohol use, physical activity, and adherence to a high-quality diet.
Lead author of the study, Daniel Sikavi, emphasized the importance of daily low-dose (81 mg) aspirin for prevention based on prior studies. Aspirin is thought to reduce the production of pro-inflammatory proteins that can promote cancer development, block signaling pathways that cause uncontrolled cell growth, influence the immune response against cancer cells, and hinder the development of blood vessels that supply nutrients to cancer cells. These mechanisms could explain aspirin’s potential role in preventing colorectal cancer.
While the study did not assess potential side effects of daily aspirin use, such as bleeding, findings suggest that healthcare providers might consider recommending aspirin to patients with less-healthy lifestyles who are at a higher risk for colorectal cancer. However, it is important to note that this was an observational study, and additional factors not accounted for may have influenced the results. Disclosure statements from the authors indicate potential conflicts of interest with pharmaceutical companies.
Overall, the research provides valuable insights into the potential benefits of regular aspirin use in reducing the risk of colorectal cancer, particularly in individuals with greater lifestyle-related risk factors for the disease. Further studies and discussions with healthcare providers may help to determine the best approach to personalized prevention strategies for colorectal cancer.
