Photo Credit: Cristian Storto Fotografia

Fecal immunochemical tests for post-polypectomy colorectal cancer surveillance may reduce the need for colonoscopy and improve screening adherence.

Stool-based post-polypectomy surveillance strategies can be safe, cost-effective, and potentially reduce the number of colonoscopies by up to 41%, according to study findings published in the journal Gastroenterology.

“Although a rationale exists for surveillance of patients at increased risk of colorectal cancer, colonoscopy-based surveillance after polypectomy causes a substantial burden for patients and health care,” wrote Beatriz Carvalho, PhD, and study coauthors.

The first part of the study compared the diagnostic performance of an FDA–approved multitarget stool DNA test and two fecal immunochemical tests (FITs) for detecting advanced neoplasia (AN) in 3,453 patients aged 50 through 75 years, with an indication for colonoscopy surveillance. Among them, 2,226 had previous polypectomy, 1,003 had previous colorectal cancer, and 224 had familiar risk. Samples for all three stool tests were taken simultaneously within 2 weeks before surveillance colonoscopy.

According to the study results, areas under the receiver operating characteristic curve for AN were 0.72 for the multitarget stool DNA test, 0.61 for FIT OC-SENSOR, and 0.59 for FIT FOB-Gold.

The second part of the study assessed the long-term impact of stool-based surveillance for the post-polypectomy indication alone. Researchers used the Adenoma and Serrated Pathway to Colorectal Cancer model to compare various stool-based surveillance strategies with colonoscopy surveillance.

Improving Colorectal Cancer Screening

Researchers reported that standard-based surveillance strategies that were at least as effective as colonoscopy surveillance required between 5.6 and 9.5 stool tests over a person’s lifetime and decreased the number of colonoscopies between 15% and 41%.

The study found that multitarget stool DNA-based surveillance was more costly than colonoscopy surveillance, while FIT-based surveillance saved costs.

“In a single round of [colorectal cancer] surveillance, the [multitarget stool DNA] test’s diagnostic accuracy in detecting AN was higher than that of FIT. Yet, microsimulation modeling showed that annual FIT-based surveillance … was at least equivalent to colonoscopy surveillance and yielded the highest reduction in a number of colonoscopies (41%), combined with the largest cost reduction,” Dr. Carvalho and colleagues wrote. “These findings provide a basis to embark on a prospective intervention study to assess the clinical utility of FIT as an alternative to colonoscopy surveillance in a post-polypectomy CRC surveillance population, which could ultimately lead to a lower burden for patients and reduced costs for society.”