POST-POLYPECTOMY surveillance colonoscopy is associated with a significantly lower risk of incident colorectal cancer (CRC), according to a new study presented at Digestive Disease Week in Washington, D.C., USA. Although surveillance colonoscopy following polyp removal is common practice and widely recommended, the extent of its effectiveness in preventing both CRC incidence and mortality remains unclear. This study, led by Samir Gupta, Veterans Affairs San Diego Healthcare System, California, USA, aimed to investigate this and build upon current guidelines and clinical practices.
The authors conducted a retrospective case-cohort study using a national sample of 516,061 veterans who underwent baseline colonoscopy with the removal of a conventional adenoma or sessile serrated lesion between 1999–2016. Among these, 1,072 incident cases of CRC and 309 fatal cases were identified, all occurring at least 6 months post-baseline polypectomy. The median age of participants at baseline was 64 years, with 97% being male and 37.8% having high-risk polyps.
The study found a 77% relative reduction in incident CRC risk associated with guideline-concordant surveillance colonoscopy over 10,421 person-years of follow-up (adjusted hazard ratio=0.23; 95% CI: 0.17–0.31). However, surveillance colonoscopy did not show a significant association with reduced CRC mortality risk over 8,777 person-years of follow-up (adjusted hazard ratio=0.83; 95% CI: 0.45–1.51). Notably, 55% of CRC cases and 40% of CRC-related deaths occurred within 4 years of the initial polyp removal, indicating that the quality of the baseline colonoscopy may significantly influence outcomes.
“Our study strengthens the evidence base behind guidelines that recommend repeat colonoscopy after polyp removal and also underscores how important baseline quality is in avoiding bad colorectal cancer outcomes,” Gupta said. He also noted that larger studies with more follow-up to examine if surveillance colonoscopy reduces colon cancer death risk would be beneficial.
Reference
Gupta S et al. Impact of post-polypectomy colonoscopy surveillance on colorectal cancer incidence and mortality: The post polypectomy surveillance (POPPSS) study. Digestive Disease Week, 18-21 May, 2024.
