Epidemiology and Endoscopic Management of Large Colon Polyps: Preliminary Analysis of a Cancer Center Experience

Abstract

Purpose: Despite the higher malignant potential of large colon polyps, their epidemiology and optimal endoscopic treatment are not fully elaborated. The aim of this study was to review our experience in patients with large colon polyps to better define the epidemiology and appropriate endoscopic management. Methods: For this IRB approved study 2915 colonoscopy with polyp reports from 2003-2006 were reviewed to identify those patients with polyps 20mm or more in size. Results: We identified 89 patients (50 males) average age of 69.7 years with 91 large polyps. Sixty-two patients were Caucasian, 14 Hispanic, 9 African-American and 3 of Asian descent. Six had prior history of colon cancer. All but one of the 91 polyps were removed with snare cautery. Saline submucosal injections were used in 34 cases. Argon plasma coagulation (APC) was used to treat residual polyps and/or resection margins in 17. The large polyp represented the only polypoid lesion in 28 patients. Mean polyp size was 27mm by endoscopic and 26mm by pathologist measurement. Half of the lesions were tubulovillous adenomas, 18 tubular adenomas, 16 villous adenomas, and 3 serrated adenomas. There were 23 adenomas with high grade dysplasia and 2 others had cancer. The remaining 7 polyps were non-neoplastic. Polyps were evenly distributed throughout the colon with 39 distal to the splenic flexure, 37 in the right colon or cecum and the remainder in the transverse. Two patients had bleeding that required repeat colonoscopies on an outpatient basis on day 1 and day 8 following polypectomies. Only one required endoscopic hemostasis but no transfusions were needed. One patient went to surgery for failed EMR. Fifty-nine patients had follow-up colonoscopies at an average of 8 months. Twenty patients (34%) had recurrence at the site on follow-up exams performed on average 6.6 months after polypectomy. Fourteen recurrences were in the right colon or cecum. One recurrence was malignant three months after initial polypectomy showed focal high grade dysplasia (HGD). Neither polyp size nor presence of HGD influenced recurrence rate. APC use (p=0.51) nor saline injection (p=0.43) affected rate of recurrence. Ethnic background was not associated with recurrence. Cecal or right colon location was associated with higher risk of recurrence (p=0.004). Conclusion: Large polyps are an infrequent finding with an ethnic distribution comparable to the institution's patient population. Mean polyp measurements by endoscopist and pathologists are comparable. Polyp recurrence is common with no relationship identified in terms of use of saline or APC, polyp size, or ethnic background. However, right colon or cecal location is associated with higher risk of recurrence.