AGA publishes clinical practice update on chemoprevention of colorectal neoplasia
Click Here to Manage Email Alerts
The American Gastroenterological Association published a clinical practice update to describe the role of medications for the chemoprevention of colorectal neoplasia.
“Colorectal cancer is the second leading cause of cancer death in the U.S., but incidence and mortality have both steadily declined since the 1980s. These encouraging trends have been attributed to a combination of increased CRC screening and population-level reduction in lifestyle risk factors,” Peter S. Liang, MD, MPH, NYU Langone Health, and colleagues wrote. “There has also been longstanding interest in the use of medications to lower CRC risk, known as chemoprevention. In this clinical practice update, we summarize the evidence and offer best practice advice on chemoprevention against colorectal neoplasia.”
Based on a literature review, these updates address the use of certain medicines like aspirin and metformin to reduce CRC incidence and mortality. Further, researchers outlined certain scenarios when medication should not be used.
The best practice advice statements on the chemoprevention of colorectal neoplasia follow.
Clinicians should use low-dose aspirin to reduce CRC incidence and mortality among individuals aged younger than 70 years with an average risk for CRC who have a life expectancy of at least 10 years, individuals who have a 10% risk for 10-year cardiovascular disease and individuals who are not at a high-risk for bleeding.
Researchers recommend the use of aspirin to prevent recurrent colorectal neoplasia among individuals with a history of CRC. Clinicians should not use non-aspirin NSAIDs in individuals at an average risk for CRC to prevent colorectal neoplasia due to the risk for adverse events.
Among individuals with type 2 diabetes, clinicians may consider the use of metformin to prevent colorectal neoplasia. Further, metformin use may reduce the risk for mortality among individuals with concurrent type 2 diabetes and CRC.
Clinicians are advised not to use calcium, vitamin D or folic acid, whether alone or together, to prevent colorectal neoplasia.
Statins should not be used to prevent colorectal neoplasia in individuals at an average risk for CRC or to reduce mortality in individuals with a history of CRC.
“There are three main takeaways. First, low-dose aspirin (eg, 81 mg) should be used for CRC prevention in individuals who are younger than 70 with at least a 10-year life expectancy, have a 10-year CV disease risk of at least 10% and not at high-risk for bleeding. Second, metformin may be considered in individuals with type 2 diabetes for prevention of colorectal neoplasia. Finally, average-risk individuals should not use non-aspirin NSAIDs, calcium, vitamin D, folic acid or statins to prevent colorectal neoplasia,” Liang told Healio Gastroenterology. “Current evidence supporting metformin consists of observational studies and a single trial, so more robust trial data are needed. Ongoing trials for vitamin D will help clarify if it has a role in chemoprevention. Finally, trials evaluating the combination of multiple medications can assess for potential synergistic effects.”
Perspective
Back to Top
Colorectal adenomas are common and diagnosed in 30% to 60% of average risk Americans undergoing colonoscopy. Colorectal cancer occurs much less frequently than adenomas but can be avoided greatly by using colonoscopy and removing adenomas. In addition to adherence to CRC screening including colonoscopy and adoption of a healthy lifestyle and diet, the use of chemoprevention has been shown — in some studies — to decrease the risk for colorectal adenomas and CRC.
The expert review on chemoprevention of colorectal neoplasia by Liang et al., provides a synthesis of published evidence on the efficacy and harms of the most well studied chemopreventive agents and recommendations for the population who may benefit from their use. The bottom line from the review are four positive statements for two agents including aspirin and metformin.
The authors state aspirin should be used in individuals at average risk for CRC, younger than 70 years who are expected to live at least once decade and have a 10-year risk for cardiovascular disease of less than 10% and not at high risk for bleeding to reduce CRC incidence and mortality and may be considered for use in individuals with a history of CRC to prevent recurrent neoplasia. Metformin may be considered for use in type 2 diabetes to prevent colorectal neoplasia and in type 2 diabetes patients with a history of CRC to reduce mortality. Calcium, vitamin D, non-aspirin, NSAID medications and folate are out as an agent for colorectal neoplasia chemoprevention and in some studies have shown harm in the colon or other organs.
The bottom line is the agents to consider for use in colorectal neoplasia prevention are used primarily to control the patients’ other diseases or risks, and their benefit on colorectal neoplasia is adjunctive to their primary disease management and do not supplant colonoscopy in individuals with a history of neoplasia or CRC screening in average risk individuals.
Collapse
Read more about
Click Here to Manage Email Alerts