Researcher calls for changes to colorectal cancer screening guidelines
Colorectal cancer will claim the lives of close to 50,000 Americans this year, according to the American Cancer Society. Screening is the most effective way to reduce the risk of dying from the disease, yet as a Penn Medicine physician argues in an editorial this week in the journal Gastroenterology, current recommendations to screen older people with a family history of colorectal cancer, specifically with colonoscopy every five years, is not justified for most patients. Chyke A. Doubeni, MD, MPH, chair of the department of Family Medicine and Community Health at the Perelman School of Medicine at the University of Pennsylvania, is the co-author of the editorial.
Colorectal cancer—which starts in the colon or rectum—is most curable when detected early through screening, and can also be prevented by detecting and removing polyps. The past three to four decades has seen an uptick in screening in the U.S. and, along with it, fewer cases of the disease and fewer lives lost as a result.
The editorial discusses the state-of-the-science in the context of a new study published in that issue of Gastroenterology that followed 144,768 men and women aged 55 to 74 for 13 years to determine the risk of colorectal cancer in those with a history of colorectal cancer in a first degree relative.
Current guidelines call for people of average risk, including those without a family history, genetic syndromes that are associated with high risk, or inflammatory bowel disease, to receive a screening colonoscopy every 10 years starting at age 50, sigmoidoscopy every 5 years, or stool occult blood test every year.
Those with first-degree relatives who have colon cancer before age 60, or two or more immediate relatives at any age, are recommended to undergo a more aggressive screening regimen, of at least one colonoscopy every five years, starting at age 40, or 10 years earlier than their youngest relative's age at diagnosis. Many questions remain, however, about the point at which patients in all risk groups can cease aggressive screening. For patients with a family history, it has not been clear whether screening colonoscopy should be used at least every five years until age 75-85 when screening is usually recommended to stop.
"The accumulated evidence shows that the risk of a colorectal cancer diagnosis in patients associated with having a family history of the condition becomes progressively smaller with increasing age, as does the association between family history and death from colorectal cancer," Doubeni said. "Current standards recommend aggressive screening until age 75 to 85, but now a growing body of evidence show that it is not necessary to continue to screen most older people with a family history that aggressively."
In light of these findings, for patients over 55, particularly those 65 years and older, having only one immediate family member with colorectal cancer, Doubeni advocates for screening as recommended for average risk individuals (colonoscopy every ten years or other recommended screening test such as fecal immunochemical test every year). Those with two or more first degree relatives with the disease, he says, should continue to receive a colonoscopy more often until more evidence is available.