Spotlight on noninvasive CRC screening

Recent publications focused on the use of noninvasive colorectal cancer (CRC) screening options.

First, the American Gastroenterological Association (AGA) Institute released a clinical practice update reviewing the available evidence and providing expert advice regarding the approach to using noninvasive CRC screening options, including evidence for their effectiveness, selection of individuals for whom these tests are appropriate, implications of a positive noncolonoscopy screening test, and opportunities to enhance the quality of noninvasive CRC screening programs. The update was published Jan. 27 by Gastroenterology.

Clinicians should be able to inform patients of available screening options, including advantages, disadvantages, and test accuracy, according to the update. They should inform patients that a positive noninvasive test is an indicator of CRC risk and should be followed by a timely, high-quality colonoscopy, the AGA said. Although strong evidence demonstrates CRC risk increased in 45- to 49-year-olds over the past 20 years, risk remains relatively low for most people before age 50 years, the update noted. “Noninvasive screening may be appropriate for these younger individuals with use of colonoscopy as patients age into higher-risk states,” the authors wrote. “However, based on risk-scoring schemes, current smoking, obesity, and low levels of physical activity may identify younger individuals at higher risk for [advanced adenomas] who may benefit from colonoscopy.”

The second study found that attendance at a biennial fecal immunochemical test (FIT) screening program in Italy was associated with reduced CRC incidence and mortality. The program started in 2005, with the target population including more than 1 million people ages 50 to 69 years and an average annual rate of response to invitation of 51.4%. Researchers extracted records of people invited up to June 2016 from the screening data warehouse and calculated self-selection-adjusted incidence rate ratios (IRRs) and incidence-based CRC mortality rate ratios (MRRs) for attendees versus nonresponders. Results were published Feb. 7 by Clinical Gastroenterology and Hepatology.

Overall, the cohort generated about 2.6 million man-years and nearly 2.9 million woman-years at risk, with 4,490 and 3,309 CRC cases, respectively. FIT program attendance was associated with an IRR of 0.65 (95% CI, 0.61 to 0.69) for men, 0.75 (95% CI, 0.70 to 0.80) for women, and 0.69 (95% CI, 0.66 to 0.72) for both sexes combined. The self-selection-adjusted IRR was 0.67 (95% CI, 0.62 to 0.72) for men and 0.79 (95% CI, 0.72 to 0.88) for women. The overall incidence-based MRR for CRC was 0.32 (95% CI, 0.28 to 0.37) for men, 0.40 (95% CI, 0.34 to 0.47) for women, and 0.35 (95% CI, 0.31 to 0.39) for both sexes combined. The adjusted MRR was 0.35 (95% CI, 0.29 to 0.41) for men and 0.46 (95% CI, 0.37 to 0.58) for women. Attendees were at slightly decreased CRC risk compared with the prescreening population, among other limitations, the study authors noted.

The final study found that implementation of an electronic patient portal primer message in a mailed FIT outreach program may increase CRC screening rates. Researchers conducted the trial in 2,339 patients enrolled in a FIT mailing program at one U.S. academic health care system from Aug. 28, 2019, to Sept. 20, 2020. They randomly assigned patients to receive standard FIT mailed outreach (control) or standard FIT mailed outreach plus an automated primer notifying them of the upcoming mailed FIT, which was sent through the electronic patient portal. The primary outcome was the screening completion rate, and secondary outcomes included the time to CRC screening from the FIT mailing date. Results were published Feb. 4 by JAMA Network Open.

At six months, the screening completion rate was higher in the intervention group than in the control group (37.6% [445 of 1,182] vs. 32.1% [371 of 1,157]; P=0.005), while the time to screening was shorter (adjusted hazard ratio, 1.24 [95% CI, 1.08 to 1.42]; P=0.003). The proportion of each screening test modality completed was similar in both groups. A subanalysis of the 900 of 1,182 patients (76.1%) in the intervention group who opened the patient portal primer message found that there was a 7.3-percentage point (95% CI, 2.3 to 12.4 percentage points) increase in CRC screening (local mean treatment effect, P=0.004). Limitations include the trial's single-center design and the possibility of selection bias, as the trial included and randomized only patients with active patient EHR portal accounts, the study authors noted.