Incorporating evidence from existing guidelines, the American College of Physicians (ACP) published a new guidance statement for colorectal cancer (CRC) screening among asymptomatic, average-risk online yesterday in the Annals of Internal Medicine.

The quality of the guidelines was assessed using the AGREE II (Appraisal of Guidelines for Research and Evaluation II) instrument with priority given to recommendations on the basis of direct evidence from research studies over modeling data. Independent review of the primary evidence was not performed.

The new ACP recommendations include:

·         Screening for CRC in average-risk adults should be performed between 50 and 75 years of age

·         The screening test chosen should be based on conversations between the provider and the patient with consideration of “benefits, harms, costs, availability, frequency, and patient preferences”

·         Screening for CRC should be discontinued in average-risk adults over 75 years of age or in adults with a life expectancy of 10 years or less

These recommendations are intended for screening of average risk individuals and do not apply to patients with a personal or family history of CRC, previous diagnosis of adenomatous polyps, or symptoms compatible with CRC.

With respect to the preferred screening tests and intervals, the current ACP guidance statement suggests the following:

·         Fecal immunochemical testing or high-sensitivity guaiac-based fecal occult blood testing every 2 years, or

·         Colonoscopy every 10 years, or

·         Flexible sigmoidoscopy every 10 years plus fecal immunochemical testing every 2 years

The authors acknowledge there are areas of insufficient evidence; specifically, trials that directly compare the efficacy and risks of different screening methods, as well as trials that address race, ethnic, and sex differences in screening and mortality.

“Identifying and optimizing the balance of benefits and harms to achieve high-value care for many persons are important,” the authors write.  

“There may be appreciable variability in patient preferences and values between tests and in whether to have screening, so clinicians should help each person arrive at a screening decision consistent with his or her values and preferences,” they conclude.

In an accompanying editorial, Michael Pignone, MD, MPH, from Dell Medical School at the University of Texas at Austin, notes: “One controversial aspect of the ACP guidance for US providers is the recommendation of biennial rather than annual stool testing, which seems to have been based on a lack of clear additional benefit from annual testing in randomized trials.”

He acknowledges however, that those studies “were not powered to rule out moderate differences in effectiveness.”

Unlike the Canadian guidelines (Canadian Task Force on Preventive Health Care), which recommend that screening begin at age 60 years, the ACP guidelines adhere to US Preventive Services Task Force recommendations of starting at age 50 years, and raise the question of whether “screening adults in their 50s is worth the resources required, compared with waiting until age 60 years,” Pignone explains.

The ACP recommendation is also in contrast to a recent clinical practice guideline published in BMJ. This guideline, developed by an international panel of experts, suggests that screening among adults aged 50 to 79 years should be limited to individuals with a 15-year CRC risk more than 3%, on the basis of a specific cancer calculation tool, QCancer.


REFERENCE: Qaseem et al: Screening for Colorectal Cancer in Asymptomatic Average-Risk Adults;