Using Risk for Advanced Proximal Colonic Neoplasia To Tailor Endoscopic Screening for Colorectal Cancer
- Thomas F. Imperiale, MD;
- David R. Wagner, MS;
- Ching Y. Lin, BS;
- Gregory N. Larkin, MD;
- James D. Rogge, MD; and
- David F. Ransohoff, MD
- From Indiana University School of Medicine, Indiana University, Roudebush Veterans Affairs Medical Center, The Regenstrief Institute, Inc., Indianapolis Gastroenterology Research Foundation, and Eli Lilly and Co., Inc., Indianapolis, Indiana; and University of North Carolina, Chapel Hill, Chapel Hill, North Carolina.
Abstract
Background: Colonoscopic screening for colorectal cancer has been suggested because sigmoidoscopy misses nearly half of persons with advanced proximal neoplasia.
Objective: To create a clinical index to stratify risk for advanced proximal neoplasia and to identify a subgroup with very low risk in which screening sigmoidoscopy alone might suffice.
Design: Cross-sectional study.
Setting: A company-based program of screening colonoscopy for colorectal cancer.
Patients: Consecutive persons 50 years of age or older undergoing first-time screening colonoscopy between September 1995 and June 2001.
Measurements: A clinical index with 3 variables was created from information on the first 1994 persons. Points were assigned to categories of age, sex, and distal findings. Risk for advanced proximal neoplasia (defined as an adenoma 1 cm or larger or one with villous histology, severe dysplasia, or cancer) was measured for each score. The index was tested on the next 1031 persons from the same screening program.
Results: Of 1994 persons, 67 (3.4%) had advanced proximal neoplasia. A low-risk subgroup comprising 37% of the cohort had scores of 0 or 1 and a risk of 0.68% (95% CI, 0.22% to 1.57%). Among the validation group of 1031 persons, risk for advanced proximal neoplasia in the low-risk subgroup (comprising 47% of the cohort) was 0.4% (upper confidence limit of 1.49%). Application of this index detected 92% of persons with advanced proximal neoplasms and, if applied following screening sigmoidoscopy, could reduce the need for colonoscopy by 40%. The marginal benefit of colonoscopy among low-risk persons was small: To detect 7 additional persons with advanced proximal neoplasia, 1217 additional colonoscopies would be required.
Conclusions: This clinical index stratifies the risk for advanced proximal neoplasia and identifies a subgroup at very low risk. If it is validated in other cohorts or groups, the index could be used to tailor endoscopic screening for colorectal cancer.
Article and Author Information
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Grant Support: In part by grant K24 DK 02756 from the National Institute of Diabetes and Digestive and Kidney Disorders (Dr. Imperiale).
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Potential Financial Conflicts of Interest: At the time of data collection, Mr. Wagner was responsible for the Indianapolis Gastroenterology Research Foundation portion of the Eli Lilly colorectal cancer program, and a portion of his salary was paid by funds received from Lilly for program management.
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Requests for Single Reprints: Thomas F. Imperiale, MD, The Regenstrief Institute, Inc., 1050 Wishard Boulevard, Indianapolis, IN 46202.
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Current Author Addresses: Dr. Imperiale: The Regenstrief Institute, Inc., 1050 Wishard Boulevard, Indianapolis, IN 46202.
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Ms. Lin: 6931 Middlebranch Avenue, Canton, OH 44721.
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Dr. Rogge: Indianapolis Gastroenterology Research Foundation, 8051 South Emerson 200, Indianapolis, IN 46237.
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Dr. Ransohoff: CB 7080, 4103 Bioinformatics Building, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7080.
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Mr. Wagner: Med Institute, 1400 Cumberland Avenue, West Lafayette, IN 47906.
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Dr. Larkin: Eli Lilly and Co., Lilly Corporate Center, DC 2111, Indianapolis, IN 46285.
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Author Contributions: Conception and design: T.F. Imperiale, D.R. Wagner, D.F. Ransohoff.
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Analysis and interpretation of the data: T.F. Imperiale, D.R. Wagner, C.Y. Lin, D.F. Ransohoff.
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Drafting of the article: T.F. Imperiale, D.F. Ransohoff.
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Critical revision of the article for important intellectual content: T.F. Imperiale, D.R. Wagner, G.N. Larkin, J.D. Rogge, D.F. Ransohoff.
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Final approval of the article: T.F. Imperiale, J.D. Rogge, D.F. Ransohoff.
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Provision of study materials or patients: D.R. Wagner, G.N. Larkin, J.D. Rogge.
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Statistical expertise: T.F. Imperiale.
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Obtaining of funding: T.F. Imperiale.
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Administrative, technical, or logistic support: D.R. Wagner, C.Y. Lin, G.N. Larkin.
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Collection and assembly of data: T.F. Imperiale, D.R. Wagner, C.Y. Lin.
- Copyright ©2004 by the American College of Physicians
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