Importance of Early Follow-up Colonoscopy in Patients at High Risk for Colorectal Polyps

PURPOSE: Minimizing the polyp miss rate during colonoscopy is important for patients at high risk for colorectal polyps. We investigated the polyp miss rate and the factors associated with it in high-risk patients. METHODS: The medical records of 163 patients who underwent follow-up colonoscopy between January 2001 and April 2010, which was within 9 months after a polypectomy, because the index colonoscopy had shown multiple (more than 3) adenomas or advanced adenoma were retrospectively reviewed. Miss rates were calculated for all polyps, for neoplastic polyps and for advanced adenomas. Factors associated with the miss rates in these patients, such as the location, shape and size of the polyp, were analyzed. RESULTS: The miss rates for polyps, adenomas, adenomas or =5 mm and advanced adenomas were 32.6%, 20.9%, 17.7%, 3.2%, and 0.9%, respectively. No carcinoma, except for one small carcinoid tumor, was missed. Flat shape and small size (<5 mm) were significantly associated with adenoma miss rate. The miss rate was significantly higher for flat-type advanced adenomas than for protruded-type advanced adenomas (27.7% vs 4.1%). CONCLUSION: The polyp miss rate in patients at high risk for colorectal polyps was higher than expected. Efforts are needed to reduce miss rates and improve the quality of colonoscopy. Also, early follow-up colonoscopy is mandatory, especially in patients at high risk.

Colonoscopic Surveillance after Curative Resection for Colorectal Cancer with Synchronous Adenoma / 대한소화기학회지

BACKGROUND/AIMS: Guidelines for current postoperative colonoscopic surveillance are not specified in colorectal cancer (CRC) patients with synchronous adenoma (SA). We performed this retrospective study to determine the postoperative colonoscopic surveillance interval for the CRC patients with SA. METHODS: One hundred and twenty-four CRC patients with SA (SA-group) and the same number of patients without SA (NSA-group) were selected from our database. Two groups were matched by the stage of CRC. Median colonoscopic surveillance period was 55 (12-99) months. The colonoscopic surveillance frequency and interval were similar between the two groups. RESULTS: Mean age was higher and male was more frequent in SA-group than NSA-group (p= 0.0001). The incidence of missed adenoma, advanced missed adenoma and metachronous adenoma (MA) were higher in SA-group (30.8% vs. 5.8% at 1st yr., p=0.0001; 4.4% vs. 0%, p=0.0001; 31.1% vs. 9.1% at 2nd yr., p=0.016) during the first consecutive two years of surveillance. The MA- and advanced-MA-free survival rate were lower in SA-group (24.6% vs. 6.6%, p=0.0001; 4.1% vs. 0%, p=0.02) during three years after surgery. Dysplasia of the SA (p=0.04; OR, 110.3; 95% CI, 1.13-10742.6) and presence of missed adenoma (p=0.036; OR, 43.6; 95% CI, 1.28-1490.1) were risk factors for the advanced MA on a multivariate analysis in SA-group. CONCLUSIONS: Postoperative colonoscopic surveillance at first year after surgery is warranted in CRC patients with SA.