Higher Rates of Serrated Polyp Detection Linked to Reduced Risk of Postcolonoscopy Colorectal Cancer

By Elesa Swirgsdin
Monday, September 26, 2022

A recent study reveals that improved detection of clinically significant serrated polyps and traditional serrated adenomas is associated with lower rates of colorectal cancer.

While higher rates of polyp and adenoma detection have previously been shown to reduce the incidence of postcolonoscopy colorectal cancer (PCCRC), studies on serrated polyps add another dimension to the quest to make colonoscopy more effective. A group of researchers led by Joseph C. Anderson, MD, Professor of Medicine at the Geisel School of Medicine at Dartmouth, collected data from the New Hampshire Colonoscopy Registry to investigate the correlation between serrated polyps and PCCRC, publishing their findings in the journal Gastrointestinal Endoscopy.

Serrated Pathway Could Be Important Predictor

The results of the study support the theory that the serrated pathway could provide a significant indicator of the risk of PCCRC.

“Our study is the first to demonstrate a lower PCCRC risk after examinations performed by endoscopists with higher clinically significant serrated polyp detection rates,” the authors note.

The researchers examined data from 19,532 patients who had follow-up events six months or more following a colonoscopy. The colonoscopies were performed by 142 endoscopists, which included 92 gastroenterologists, with the remaining 50 comprised of general surgeons, colorectal surgeons and family practitioners.

Of the people with follow-up events, 128 patients were diagnosed with colorectal cancer.

The team found that detection rates mattered: When endoscopists with rates of 3% to 9% or higher performed the colonoscopies, the risk for PCCRC six months or more after the exam was notably lower than when endoscopists with rates below 3% performed the colonoscopies.

A significantly higher number of gastroenterologists were in the group with high detection rates than the group with lower detection rates. The researchers also observed that endoscopists with adenoma detection rates (ADR) of 25% or higher more frequently had higher rates of serrated polyp detection as well.

“It may be reasonable to question whether a separate serrated detection rate is needed in addition to ADR,” the team says in a discussion of the study. “These data support our suggestion that endoscopists, even those with an ADR of 25% or higher, calculate their SDR at least once, a recommendation supported by a recent review of the American Gastroenterological Association.”

Future Research

The study has limitations. Researchers lacked information on specific endoscopic techniques. They also would have liked to know more about the molecular characteristics of the diagnosed cancers.

Still, the results confirm the need for a serrated polyp detection rate benchmark and “validate the use of [serrated polyp detection rates] as a clinically relevant quality measure for endoscopists,” the authors write.