The American College of Physicians (ACP) updated guidance reaffirming its stance that colorectal Cancer screening should wait until age 50 for average-risk, asymptomatic adults.

The ACP recommends that clinicians “should discuss the uncertainty around benefits and harms of screening” with individuals ages 45 to 49, and that screening be dropped in asymptomatic average-risk adults older than 75 and those with a life expectancy of 10 years or less, noted Amir Qaseem, MD, PhD, MHA, of the ACP, and colleagues in the Annals of Internal Medicine.

“This updated guidance will help physicians determine the evidence-based course for their patients for screening for colorectal cancer and avoid unnecessary screening in this population,” said Omar Atiq, MD, president of the ACP, in a press release. “Physicians and patients should select the screening test based on a discussion of the benefits, harms, costs, availability, frequency, and patient preferences.”

ACP’s guidance stands in contrast to the American Cancer Society (ACS) and the U.S. Preventive Services Task Force (USPSTF) new recommendations that Colorectal Cancer Screening begin at age 45 for the asymptomatic average-risk population.

ACP acknowledged that the incidence of colorectal cancer has slightly increased in persons younger than 50, while it has decreased in those ages 50 to 64, and even more sharply decreased in persons ages 65 and older.

However, considering the potential harms that can occur with colorectal cancer screening — including cardiovascular and gastrointestinal events (serious bleeding, perforation, myocardial infarction, and angina), unnecessary follow-ups, and costs for findings deemed clinically unimportant — the net benefit of screening “is much less favorable in average-risk adults between ages 45 and 49 years than in those aged 50 to 75 years,” Qaseem and colleagues wrote.

According to David E. Rivadeneira, MD, MBA, director of Northwell Health Cancer Institute at Huntington Hospital in Huntington, New York, the ACP’s recommendation reinforces the fact that “screening saves lives.” However, he told MedPage Today that the conflicting recommendations “send mixed messages, unfortunately.”

“We have seen a striking increase in colon and rectal cancer in patients who are less than 50, so the issue is the age,” he said. “Should you go with 45 or 50? I think it will be patient driven and doctor driven, and I think gastroenterologists, colorectal surgeons like myself, and cancer doctors are probably going to say let’s lean towards 45 because we’ve seen such an increase in younger patients.”

“In my world, I’m very often seeing patients in their 40s with colon cancer, so I feel very comfortable recommending 45,” he added.

Aasma Shaukat, MD, MPH, of the NYU Grossman School of Medicine in New York City, took a stronger stance, telling MedPage Today that the ACP guidance is “disappointing and undermines efforts to unify our message to increase the uptake of screening.”

She noted that while its true that most colorectal cancers occur after the age of 50, and there aren’t any clinical studies demonstrating the benefit of screening under the age of 50, “what we do know is that there is a rising trend of colorectal cancers in those younger than 50.”

“We also have evidence that colon cancers under the age of 50 are diagnosed at advanced stages,” she said. “We also know that cancer incidence rates at age 45 are what they were for age 50 almost 30 years ago when we started screening.”

“Finally, we know screening reduces incidence and mortality,” she added.

According to the ACP, individuals 50 and over should — in consultation with their clinicians — undergo an appropriate screening test based on discussion of benefits, harms, costs, availability, frequency, and patient values and preferences.

Recommended screening tests include:

• Fecal immunochemical or high-sensitivity guaiac fecal occult blood testing every 2 years
• Colonoscopy every 10 years
• Flexible sigmoidoscopy every 10 years plus a fecal immunochemical test every 2 years

However, the ACP guidance further differs from that of the ACS and USPSTF in recommending against fecal DNA or CT colonography screening.

In the case of fecal DNA testing, Rivadeneira argued that some individuals just don’t want to have a colonoscopy, whether its due to the risks of perforation or bleeding, or because of issues with anesthesia.

“I would say if they can’t undergo a colonoscopy I do think [fecal DNA] is a reasonable choice,” he said. “Some screening is better than no screening.”

In an accompanying editorial, Michael Bretthauer, MD, PhD, of the University of Oslo in Norway, and Yu-Xiao Yang, MD, of the University of Pennsylvania Perelman School of Medicine in Philadelphia, said that while the new ACP guidance will spark debate in the U.S., “it is more in line with international guidelines.”

They noted that in the new guidance, the ACP “emphasized the importance of clinical and empirical data in the context of absolute disease prevalence, rather than relying solely on disease modeling.”

They also pointed out that, unlike the USPSTF and ACS guidance, the ACP took cost into consideration.

“The new recommendations, surprising as they may be for some, may turn the tide toward more dispassionate, evidence-based assessment of absolute benefits and harms of colorectal cancer screening,” they wrote.

As might be expected, the guidance came with some pushback from medical societies.

The Prevent Cancer Foundation said it “strongly opposes” the updated guidance, as it conflicts with the latest evidence-based screening recommendations from “organizations working in the cancer screening space every day.”

The American College of Radiology also weighed in, calling ACP’s recommendation against the use of CT colonography screening “a step backward,” particularly when it comes to underserved areas with lower screening rates and higher colorectal cancer mortality rates.

“We need more testing options – not fewer,” the organization said in a press release.