USPSTF Poised to Change Advice for Low-Dose Aspirin to Prevent Colorectal Cancer

Colon

Based on a growing body of long-term evidence demonstrating the benefits of aspirin for colorectal cancer (CRC) prevention and risk reduction, the US Preventive Services Task Force (USPSTF) issued a draft guideline today recommending the use of low-dose aspirin for certain individuals for the prevention of CRC and cardiovascular disease (CVD).

“Each person has only one decision to make—whether or not to take aspirin for prevention,” USPSTF member Douglas K. Owens, MD, MS, said in a statement. “To help individuals and their clinicians make this decision, the Task Force integrated the evidence about the use of aspirin to prevent cardiovascular disease and colorectal cancer into one recommendation on the use of aspirin.”

In the draft guideline, the USPSTF issued a Grade B recommendation for low-dose aspirin in adults aged 50 to 59 years for the prevention of CRC and CVD. This recommendation would apply to those with a >10% 10-year CVD risk; who are not at increased risk for bleeding; have a life expectancy of at least 10 years, and who are willing to take low-dose aspirin daily for at least 10 years.

A Grade B recommendation means that USPSTF suggests that clinicians offer or provide the service because there is a “high certainty that the net benefit of the intervention is moderate or there is moderate certainty that the net benefit is moderate to substantial.”

For individuals aged 60-69, the agency issued a Grade C recommendation for preventive aspirin use in individuals aged 60 to 69 years. For this group, the decision to recommend aspirin to prevent CVD and CRC in higher-risk adults should be an individual one for selected patients, based on their preferences and circumstances, as well as the practitioner’s professional judgment.

USPSTF noted that currently there is insufficient evidence that low-dose aspirin use would be beneficial in preventing CVD and CRC in individuals aged <50 or ≥70 years.

The clinical considerations underpinning the USPSTF draft recommendations include that patients need to take aspirin for at least 5 to 10 years to realize the potential benefit of low-dose aspirin in CRC prevention.

This draft recommendation is open for public comment until October 12, 2015. If it becomes a final recommendation statement, the USPSTF would be reversing its previous decision against the use of aspirin for CRC prevention.

Commenting on an earlier study on long-term aspirin use and prevention which was reported at the annual meeting of the American Association for Cancer Research in April,2 Laura Metcalfe, MSN, RN, APN-C, AOCNS, of the John Theurer Cancer Center in Hackensack, New Jersey, noted that, “Colorectal cancer is the third leading cause of cancer death in the United States for both men and women. While screening and other strategies (diet, exercise, maintaining a BMI within the normal range) can also reduce CRC risk, for many reasons, these strategies are not always employed. To my mind, something as simple as an aspirin a day as a preventive strategy would likely be more readily embraced by the general population.

“Unless a patient has a higher risk for bleeding or ulcers, for example, a baby aspirin a day taken after eating so as not to take on an empty stomach, should not present any great risk for the average person.”

Benefits for Lynch Syndrome Carriers

In related research published recently in the Journal of Clinical Oncology, long-term aspirin use significantly lowered the risk of developing CRC in Lynch syndrome carriers while ameliorating the added risk associated with obesity, according to conclusions from a new analysis from the CAPP2 trial.3

In the CAPP2 trial, Lynch syndrome carriers were randomized to aspirin at 600 mg per day or an aspirin placebo. Individuals in the study had a history of a cured Lynch syndrome—related neoplasm and had an intact colon. The primary endpoint of the study was the development of CRC.

In obese Lynch syndrome carriers, the risk of developing CRC was 134% higher compared with a reference group of normal and underweight participants (HR, 2.34; 95% CI, 1.17-4.67; P = .02), whereas in the placebo arm, the risk of developing CRC increased by 175% when BMI was >30 kg/m2 (HR, 2.75; 95% CI, 1.12-6.57; P = .03). However, in the aspirin arm, the increased CRC risk associated with obesity was not statistically significant (HR, 2.00; 95% CI, 0.61-6.70).

“This research adds to the growing body of evidence which links an increased inflammatory process to an increased risk of cancer. Obesity increases the inflammatory response," said coauthor John Burn, MD, in a statement. Burn, a professor of Clinical Genetics at Newcastle University, led the international research collaboration. "One explanation for our findings is that the aspirin may be suppressing that inflammation which opens up new avenues of research into the cause of cancer.”

“The lesson for all of us is that everyone should try to maintain a healthy weight, and for those already obese, the best thing is to lose weight," noted lead author John C. Mathers, PhD, professor of Human Nutrition at Newcastle University, in a statement. "However, for many patients this can be very difficult, so a simple aspirin may be able to help this group.”

References

1. Draft Recommendation Statement: Aspirin to Prevent Cardiovascular Disease and Cancer website http://www.uspreventiveservicestaskforce.org/Page/Document/draft-recommendation-statement/aspirin-to-prevent-cardiovascular-disease-and-cancer. Updated September, 2015. Accessed September 15, 2015.

2. Cao Y, Nishihara R, Wu K, et al. Long-term aspirin use of aspirin and risk of cancer. Presented at: 2015 AACR Annual Meeting; April 18-22; Philadelphia, PA. Abstract 3197.

3. Movahedi M, Bishop DT, Macrae F, et al. Obesity, Aspirin, and Risk of Colorectal Cancer in Carriers of Hereditary Colorectal Cancer: A Prospective Investigation in the CAPP2 Study [Published online ahead of print August 17, 2015]. J Clin Oncol. doi: 10.1200/JCO.2014.58.9952