CLINICAL–ALIMENTARY TRACT Five-Year Colon Surveillance After Screening Colonoscopy DAVID A.LIEBERMAN,* DAVID G. WEISS, ‡ WILLIAM V.HARFORD, § DENNIS J. AHNEN, 储 DAWN PROVENZALE, ¶ STEPHEN J. SONTAG, # THOMAS G. SCHNELL, # GREGORIO CHEJFEC, # DONALD R.CAMPBELL,** JAYASHRI KIDAO, ‡‡ JOHN H. BOND, §§ DOUGLAS B. NELSON, §§ GEORGE TRIADAFILOPOULOS, 储储 FRANCISCO C. RAMIREZ, ¶¶ JUDITH F. COLLINS, ## TIINA K. JOHNSTON, ## KENNETH R. MCQUAID,*** HARINDER GAREWAL, ‡‡‡ RICHARD E. SAMPLINER, ‡‡‡ ROMEO ESQUIVEL, ‡‡‡ and DOUGLAS ROBERTSON §§§ *Department of Veterans Affairs Medical Center, Portland, Oregon; ‡ Department of Veterans Affairs Medical Center, Perry Point, Maryland; § Dallas, Texas; 储 Denver, Colorado; ¶ Durham, North Carolina; # Hines, Illinois; **Kansas City, Missouri; ‡‡ Long Beach, California; §§ Minneapolis, Minnesota; 储储 Palo Alto, California; ¶¶ Phoenix, Arizona; ## Portland, Oregon; ***San Francisco, California; ‡‡‡ Tucson, Arizona; and §§§ White River Junction, Vermont See editorial on page 1364. Background & Aims: Outcomes of colon surveillance after colorectal cancer screening with colonoscopy are uncertain. We conducted a prospective study to mea- sureincidenceof advanced neoplasia in patients within 5.5 years of screening colonoscopy. Methods: Three thousand one hundred twenty-one asymp- tomatic subjects, age 50 to 75 years, had screening colonoscopy between 1994 and 1997 in the Depart- ment of Veterans Affairs. One thousand one hundred seventy-one subjects with neoplasia and 501 neopla- sia-free controls were assigned to colonoscopic sur- veillance over 5 years. Cohorts were defined by base- line findings. Relative risks for advanced neoplasia within 5.5 years were calculated. Advanced neoplasia was defined as tubular adenoma greater than >10 mm,adenoma with villous histology, adenoma with high-gradedysplasia, orinvasivecancer. Results: Eight hundred ninety-five (76.4%)patientswith neoplasia and 298 subjects (59.5%) without neopla- sia atbaseline had colonoscopy within 5.5 years; 2.4% ofpatientswith no neoplasia had interval advanced neoplasia. The relative risk in patients with baseline neoplasia was 1.92 (95% CI:0.83– 4.42) with 1 or 2 tubular adenomas <10 mm, 5.01 (95% CI: 2.10 –11.96) with 3 or more tubular adeno- mas <10 mm, 6.40 (95% CI: 2.74 –14.94) with tubu- lar adenoma >10 mm, 6.05 (95% CI: 2.48 –14.71) for villous adenoma, and 6.87 (95% CI: 2.61–18.07) for adenoma with high-grade dysplasia. Conclusions: There isa strong association between results of baseline screening colonoscopy and rate of serious incidentlesions during 5.5 years of surveillance. Patients with 1 or 2 tubular adenomas less than 10 mm representa low-risk group compared with other patients with colon neoplasia. S urveillancewith colonoscopyis currentlyrecom- mended after the detection and removal of colonic neoplasia (defined as nonmalignant adenoma or invasive cancer) because of the risk of newly discovered neoplasia during follow-up, some of which may be malignant. 1,2 In prior studies of adenoma-bearing patients, invasive can- cer was found in 0.3%–1.0% within 3 years of baseline colonoscopy. 3–10 However, it is evident that most patients with adenomas will not benefit from surveillance; 30%– 50% of adults will develop colon adenomas during their lifetime,and only 6% willdevelop colorectal cancer. 11 Surveillance colonoscopy represents an important and costly component of any colon screening program 12 and ideally should betargeted atpatientsmostlikely to develop colorectal cancer. Several studies have found an association between findings at the baseline colonoscopy and subsequent pathology during surveillance, including number of adenomas and adenoma size ⱖ10 mm. 13–16 Current recommendations call for repeatscreening colonoscopy at 10 years for patients with no neoplasia at baseline and surveillance at 5 years or more for patients with 1 or 2 small (⬍10 mm) tubular adenomas and at 3 years in patients with advanced neoplasia or more than 2 adenomas. 1 Recommendations for surveillance intervals afterremovalof canceror adenomaswith high-grade dysplasia range from 1 to 3 years. 1,2,17,18 Few surveillance studies have been performed that include patients with negative baseline colonoscopy, 19 –23 and most studies ex- cluded patients with very high-risk lesions. 3–10 In Veterans Affairs Cooperative Study 24 No. 380,3121 asymptomatic participants had screening colonoscopy, all visible polyps were removed, and patients were classi- fied by their most advanced histologic lesion;1171 (37.5%) individuals had neoplasia and were assigned to follow-up regimens over 5 years. A subset of participants ©2007 by the AGA Institute 0016-5085/07/$32.00 doi:10.1053/j.gastro.2007.07.006 CLINICAL– ALIMENTARY TRACT GASTROENTEROLOGY 2007;133:1077–1085