Randomized Colorectal Cancer Screening Trial Includes Risk-Stratified Arm
Douglas K. Rex, MD, FASGE reviewing Chen H, et al. Am J Gastroenterol 2020 Apr 13.
Colorectal cancer (CRC) screening can be offered to patients as a menu of screening options; sequential testing (colonoscopy offered first with another testing option offered when colonoscopy is refused); or a risk-stratified approach, in which colonoscopy is offered to high-risk patients and fecal immunochemical testing (FIT) is offered to low-risk patients. Thus far, no randomized controlled trial (RCT) has evaluated the risk-stratified approach.
In a trial from China, 19,546 persons aged 50 to 74 years were randomized into 3 groups: one-time colonoscopy, annual FIT, or risk-adapted screening. The cutoff for positive FIT was 4 µg Hgb/g feces, resulting in a positive FIT rate of 14%. Risk was assigned based on the Asia-Pacific Colorectal Screening score, which uses age, gender, CRC history in first-degree relatives, smoking, and body mass index. In the risk arm, 18.9% of patients were assessed as high risk.
Overall participation rates in the colonoscopy, FIT, and risk arms were 42.5%, 94%, and 85.2%, respectively. On an intent-to-screen basis, CRC rates were 0.23%, 0.09%, and 0.17%, respectively. Advanced adenoma rates were 2.17%, 1.04%, and 1.49%, respectively. The numbers of colonoscopies to detect one advanced neoplasm were 18, 10, and 11, respectively.
![d-rex](/wp-content/uploads/d-rex.jpg)
COMMENTThis is the first major RCT to include a risk-stratified screening arm, and the risk-based arm had a higher detection rate of advanced adenomas than the FIT arm, with a similar number of colonoscopies.
A major deficiency of this and other trials remains failure to include the sequential approach. For example, if patients in either the colonoscopy arm or the high-risk group of the risk-stratified arm decline colonoscopy, why not offer FIT? Also, it would be informative for these trials to report sessile serrated lesion detection rates, which colonoscopy would be expected to excel in.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
CITATION(S)
Chen H, Lu M, Liu C, et al. Comparative evaluation of participation and diagnostic yield of colonoscopy vs fecal immunochemical test vs risk-adapted screening in colorectal cancer screening: interim analysis of a multicenter randomized controlled trial (TARGET-C). Am J Gastroenterol 2020 Apr 13. (Epub ahead of print) (https://doi.org/10.14309/ajg.0000000000000624)