Colon Polyp Recurrence: Predictors of Early Development of Significant Polyp

Abstract

Background/Aims: It has been reported that the recurrence rate of colon polyp after polypectomy is around 39% in 3 years. It, however, is recommended that 3 year is optimal follow up period after polypectomy in the meaning of significant polyp (size ≥1cm or dysplasia) recurrence. Initial polyp number, presence of significant polyp, and age factor are considered as a risk factor for recurrence of polyp after polypectomy. We retrospectively determined the cumulative recurrence rate of neoplastic polyps and significant polyps in patients who underwent polypectomy. Methods: Ninety-seven patients underwent total colonoscopy 5-81 months after initial endoscopic polypectomy. All polyps were endoscopically removed by methods of biopsy forcep removal/snare polypectomy and an adenoma was considered as significant if the diameter was ≥1cm and/or villous component and/or severe dysplasia were present. Results: (1) Mean age of patient who underwent polypectomy was 57 and 70% was male. Mean colonoscopic follow-up period was 25 months. Mean number of initial polyp was 2.2 (range, 1-11) and significant polyps were observed in 43%. (2) Cumulative recurrence rate of colon polyp was 13.8% in 1 year, and 60% in 3 year, which is compared to the finding that cumulative recurrence rate of significant polyps was 2.5% and 31%, respectively. Kaplan-Meier projections estimate that 50% will have a significant polyp recurrent polyp within 56 months (95% CI, 34-78 months). (3) There was no difference in overall cumulative polyp and significant polyp recurrence according to the methods of polyp removal, presence of initial significant polyp, initial location of colon polyp. However, significant difference in overall cumulative polyp and significant polyp recurrence was noted according to the initial polyp number (p<0.05). The age at the diagnosis of colon polyp was significant only in overall polyp recurrent rate (p=0.01). (4) In cox-regression analysis, apart from initial polyp number, no other parameters contributed to significant polyp recurrence. Patients who initially had one polyp showed 15% of significant polyp recurrence within 3 years regardless of age. Conclusion: Significant polyp recurrence is very rare within one year after polypectomy. Patients with single polyp are identified low risk group and their surveillance examination may be delayed beyond the standard 3 years. When performing surveillance colonoscopy in patient s with 2 or more polyps, initial polyp number and age should be considered.