Not so fast with earlier screening for colorectal cancer (CRC), at least according to one professional group.
The American College of Physicians published updated clinical guidance maintaining 50 as the age when clinicians should start screening for CRC in patients who are asymptomatic and at average risk.
The recommendation conflicts with guidelines from the American Cancer Society and the U.S. Preventive Services Task Force, which lowered the recommended age to start screening to age 45.
Although the rate of CRC has increased among adults aged 45-49, the incidence is 35.1 cases per 100,000 people, much lower than among persons aged 50-64 (71.9 per 100,000) and those aged 65-74 (128.9 per 100,000), the guidance notes.
“The net benefit of screening is much less favorable in average-risk adults between ages 45 and 49 years than in those aged 50-75 years,” the authors wrote. “Clinicians should discuss the uncertainty around benefits and harms of screening in this population.”
The ACP’s updated guidance is provocative and should be considered in the context of other groups’ recommendations, not as superseding them just because it is the most recently published document, according to Jeffrey A. Meyerhardt, MD, MPH, codirector of the Colon and Rectal Cancer Center at Dana-Farber Cancer Institute, Boston.
“As with a lot of the things we do in medicine, it is balancing risk and potential benefit,” Dr. Meyerhardt said in an interview. “If a patient is informed that at a younger age doing screening is very likely not to find anything and there are some risks to screening, that patient could then weigh the risks and benefit with their provider.”
Three screening approaches
The new guidance statement is based on a critical review of existing clinical guidelines, evidence reviews, and modeling studies. The guidance does not apply to patients who have long-standing inflammatory bowel disease and those with a family history of CRC.
The guideline also addresses when clinicians should stop screening – at age 75 – and what types of tests patients should choose from.
After discussing the benefits, harms, cost, availability, and patient preferences, clinicians and patients should select one of three screening approaches, according to the ACP: a fecal immunochemical or high-sensitivity guaiac fecal occult blood test every 2 years; colonoscopy every 10 years; or flexible sigmoidoscopy every 10 years plus a fecal immunochemical test every 2 years.
They should avoid CRC screening tests that use stool DNA, CT colonography, capsule endoscopy, urine, or serum, according to the guidance.
A balancing act
Some physicians view starting screenings at age 45 as a settled argument.
“The entire nation is now focused on increasing screening capacity and getting everyone screened,” said Richard C. Wender, MD, professor and chair of family medicine and community health at the University of Pennsylvania, Philadelphia, who was not involved in the new guidelines. “There is not a controversy about age to start, and I anticipate that this paper won’t create a new one.”
The epidemiology of CRC is changing rapidly, Dr. Wender said.
“While CRC mortality is going down in older age groups, mortality is now rising in younger people,” he said. “While cancer incidence is lower in the 45- to 49-years-old group, the precursors to cancer are present and can be found in a substantial percentage of patients – the same percentage as 50- to 55-year-olds.”
Dr. Meyerhardt said in an interview that the recommendation to start screening at age 45 was reasonable but that more people need to be screened to detect CRC than the older population.
“Ultimately, one’s going to have to consider the various recommendations from these different societies when having a patient in front of you as a primary care or other physician to discuss screening in someone who’s what we call average risk,” he said.
Younger patients who notice any possible symptoms of CRC such as blood in stool or changes in bowel habits should discuss them with a physician, he said.
The ACP also differs from other groups in not recommending stool DNA tests such as Cologuard (Exact Sciences). Dr. Wender said this test is the least cost effective based on comparing adherence for other options. “If Cologuard can lead to higher adherence and there are data suggesting it can, then relative cost-effectiveness looks better.”