FIT could reduce colonoscopies by 70% but may miss 30% of cancers
Using annual fecal immunochemical tests for surveillance in patients with intermediate risk for colorectal cancer could reduce colonoscopies and cut costs, according to research published in Gut, but researchers warned that may come at the cost of missed cancers and adenomas.
Amanda J. Cross, PhD, of the department of surgery and cancer at Imperial College London, and colleagues wrote that while colonoscopies help reduce incidence of CRC, they can lead to anxiety or discomfort among patients.
“Colonoscopy surveillance places great demand on endoscopy services, accounting for 20% of colonoscopies in the U.K.,” they wrote. “Further increases in endoscopy demand due to widespread implementation of CRC screening and higher rates of primary care referrals for suspected CRC give grounds for finding alternative surveillance methods.”
Researchers recruited patients with intermediate risk for CRC who were recommended to undergo 3-yearly surveillance for the study. Researchers offered patients FIT at years 1, 2 and 3. Patients who returned a FIT at year 1 were included in the study (n = 5,938).
Individuals who tested positive (at least 40 µg/g hemoglobin) at years 1 or 2 were offered an early colonoscopy. Investigators determined diagnostic accuracy for CRC and advanced adenomas and calculated incremental costs per additional adenoma and CRC detected by colonoscopy compared with FIT.
When assessing at the 40 µg/g hemoglobin threshold, researchers found that the 3-year cumulative positivity was 13% and increased to 29% when the threshold was lowered to 10 µg/g hemoglobin.
The 3-year program sensitivity for the 40 µg/g hemoglobin threshold was 59% for CRC and 33% for advanced adenoma. At the 10 µg/g hemoglobin threshold it was 72% and 57%, respectively.
Researchers found that the incremental costs per additional advanced adenoma and CRC detected by colonoscopy compared with FIT were 7,354 pounds sterling and 180,778 pounds sterling, respectively.
Cross and colleagues wrote that their findings show that FIT could fill a need as a surveillance tool in patients with intermediate risk for CRC, but more research and financial analysis is needed to determine its exact role.
“If low-threshold annual FIT was implemented instead of 3-yearly colonoscopy, numbers of colonoscopies could be reduced by more than 70% with significant cost savings,” they wrote. “However, this would come at the cost of missed [advanced colorectal neoplasia]; depending on the threshold, annual FIT could miss 30% to 40% of CRCs and 40% to 70% of [advanced adenomas].” – by Alex Young
Disclosures: Cross reports no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.