Long term outcomes of colon polyps with high grade dysplasia following endoscopic resection

Background The risk of recurrent colonic adenoma associated with high-grade dysplasia (HGD) colon polyps at baseline colonoscopy remains unclear. We conducted a clinical cohort study with patients who underwent polypectomy during screen colonoscopy to assess recurrent colonic adenoma risk factors. Methods 11,565 patients at our facility underwent screen colonoscopy between September 1998 and August 2007. Data from patients with HGD colon polyps who had undergone follow-up colonoscopy were included for analysis. Results Data from 211 patients was included. Rates of metachronous adenoma and advanced adenoma at follow-up were 58% and 20%, respectively. Mean follow-up period was 5.5 ± 1.8 (3–12) years. Univariate logistic regression analysis revealed that an adenoma count of ≥ 3 at baseline colonoscopy was strongly associated with overall recurrence, multiple recurrence, advanced recurrence, proximal recurrence, and distal adenoma recurrence with odds ratios of 4.32 (2.06–9.04 95% CI), 3.47 (1.67–7.22 95% CI), 2.55 (1.11–5.89 95% CI), 2.46 (1.16–5.22 95% CI), 2.89 (1.44–5.78 95% CI), respectively. Multivariate analysis revealed gender (male) [ P = 0.010; OR 3.09(1.32–7.25 95% CI)] and adenoma count ≥ 3 [ P = 0.002; OR 3.08(1.52–6.24 95% CI)] at index colonoscopy to be significantly associated with recurrence of advanced adenoma. Conclusion Recurrence of colonic adenoma at time of follow-up colonoscopy is common in patients who undergo polypectomy for HGD colon adenomas during baseline colonoscopy. Risk of further developing advanced adenomas is associated with gender and the number of colon adenomas present.