By Agata Blaszczak-Boxe

Colonoscopy conducted every 10 years and annual fecal immunochemical tests are now considered the best options for colorectal cancer screening, according to new recommendations by the United States Multi-Society Task Force on colorectal cancer.

The MSTF ranked colorectal cancer screening tests into three levels based on test effectiveness at detecting cancer, cost and other factors.

“There are at least six screening tests currently available,” Douglas Rex, MD, distinguished professor of medicine at Indiana University, in Indianapolis, and lead author of the recommendations, told General Surgery News. “Generally, it’s too much for physicians and patients to review the advantages and disadvantages of all of the tests, which are quite variable. The new guideline ranks the tests and thereby simplifies the selection of screening tests.”

The first-level recommendations for patients with CRC are colonoscopy and FIT. People who refuse those options can choose second-level alternatives: CT colonography performed every five years, a FIT–fecal DNA test every three years or flexible sigmoidoscopy every five to 10 years. Individuals who decline the first- and second-level options can be offered capsule colonoscopy every five years, according to the recommendations. The guidelines were published jointly in Gastroenterology (doi: 10.1053/j.gastro.2017.05.013), American Journal of Gastroenterology (doi: 10.1038/ajg.2017.174) and GIE: Gastrointestinal Endoscopy (doi: 10.1016/j.gie.2017.04.003).

The task force advised against using the Septin9 serum assay because of its low effectiveness in detecting cancer, inability to detect advanced adenomas and high cost.

The task force evaluated research on CRC screening tests published between 2005 and 2016. The investigators examined data on the sensitivity of CRC tests, cost, availability, popularity with patients and potential obstacles to use, such as lack of insurance reimbursement.

In addition, the task force analyzed data on CRC incidence, concluding that people with an average risk for the disease should begin screening at age 50 years. Blacks should do so earlier—at age 45—partly because of higher incidence rates of CRC and earlier onset of disease in this group than in other races.

People with one first-degree relative diagnosed with CRC or advanced adenoma before age 60 should undergo colonoscopy every five years beginning at age 40, or 10 years before the age that relative was diagnosed with one of these conditions, according to the guidelines. The same recommendation applies to people with two first-degree relatives diagnosed with CRC or an advanced adenoma at any age.

People with one first-degree relative who was diagnosed with CRC or an advanced adenoma at age 60 or later should begin screening at age 40 and should follow recommendations for testing and interval screening for average-risk individuals.

The task force noted that the incidence of CRC is rising in people younger than age 50 for reasons that remain unclear. To reduce CRC morbidity and mortality in this age group, physicians should evaluate patients with colorectal symptoms such as hematochezia, iron deficiency anemia and melena with a negative upper endoscopy, according to the recommendations.

James C. DiLorenzo, MD, a gastroenterologist at Montefiore Health System, in New York City, who specializes in CRC and was not involved in the new recommendations, agreed that the menu of available screening options can be overwhelming for patients and physicians. The new recommendations will be able to streamline the discussion between doctors and patients who are eligible for CRC screening, he said. The recommendations “do a very good job at drawing a distinction between the different tests in terms of what they are able to accomplish and what their limitations are.”