Elevated CRC Risk in Advanced Serrated Polyps Confirmed in New Research

A meta-analysis of 14 studies published in Gastrointestinal Endoscopy involving nearly 500,000 patients highlights the elevated risk of colorectal cancer (CRC) and advanced polyps associated with serrated polyps (SPs), particularly those classified as advanced. The findings provide critical evidence supporting current surveillance recommendations for patients with advanced SPs. 

Patients with advanced SPs, defined as SPs ≥10 mm or those with dysplasia, had a significantly higher incidence of CRC compared to those with nonadvanced SPs or normal colonoscopy findings. The CRC incidence per 1,000 person-years was 2.09 for advanced SPs, compared to 0.50 for nonadvanced SPs and 0.44 for normal colonoscopy findings. 

SPs ≥10 mm were associated with a relative risk (RR) of 2.61 for CRC compared to SPs <10 mm, while SPs with dysplasia carried a similar elevated risk (RR: 2.71). Notably, the CRC risk for advanced SPs was comparable to that of advanced adenomas, reinforcing the need for consistent follow-up strategies.   The study also found no increased CRC or advanced polyp risk associated with proximal versus distal SPs or with having three or more SPs versus 1 or 2. 

The findings affirm the importance of 3-year surveillance intervals for patients with advanced SPs. "CRC risk is significantly higher in patients with baseline advanced SPs after 4.9 years of follow-up," the study concluded, emphasizing that the risk magnitude is similar to that observed with advanced adenomas. 

This evidence provides clarity on SP risk stratification, supporting the tailored surveillance recommendations for advanced SPs while suggesting that less intensive follow-up may suffice for nonadvanced SPs or other low-risk findings. 

Surveillance intervals should continue to align with guidelines for advanced adenomas, with a 3-year follow-up for advanced SPs. Further research may refine risk estimates for specific SP subgroups. 

Reference
Baile-Maxía S, Mangas-Sanjuán C, Ladabaum U, et al. Risk factors for metachronous colorectal cancer or advanced lesions after endoscopic resection of serrated polyps: a systematic review and meta-analysis. Gastrointest Endosc. 2024;100(4):605-615.e14. doi:10.1016/j.gie.2024.05.021