Development and Validation of a Colon Cancer Risk Assessment Tool for Patients Undergoing Colonoscopy

• Published in: The American journal of gastroenterology Vol. 104; no. 6; pp. 1508 - 1518
• Main Authors: Kastrinos, Fay, Allen, John I, Stockwell, David H, Stoffel, Elena M, Cook, Earl F, Mutinga, Muthoka L, Balmaña, Judith, Syngal, Sapna
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.06.2009; Wolters Kluwer Health Medical Research, Lippincott Williams & Wilkins
• Subjects: Biological and medical sciences; Colonic Neoplasms - diagnosis; Colonic Neoplasms - epidemiology; Colonoscopy - methods; Digestive system. Abdomen; Endoscopy; Female; Gastroenterology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Middle Aged; Morbidity; Outpatients; Pilot Projects; Reproducibility of Results; Retrospective Studies; Risk Assessment - organization & administration; Risk Factors; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Surveys and Questionnaires; Tumors; United States - epidemiology; United States; Colonic disease; Human; Colon cancer; Colonoscopy; Risk factor; Gastroenterology; Digestive diseases; Intestinal disease; Malignant tumor; Endoscopy; Cancer
• ISSN: 0002-9270; 1572-0241; 1572-0241
• DOI: 10.1038/ajg.2009.135

Diagnostic criteria for hereditary colorectal cancer (CRC) are complex. "Open-access" colonoscopy makes it challenging to identify who needs genetic evaluation, intensive surveillance, and screening for extracolonic tumors. Our aim was to develop a simple, preprocedural risk assessment tool to identify who may be at highest risk for CRC. A total of 631 outpatients undergoing colonoscopy at two academic practices completed a questionnaire assessing personal and family histories of CRC, polyps, and Lynch syndrome (LS)-associated malignancies. Subjects were considered to be high-risk if one of the nine prespecified characteristics of hereditary CRC syndromes was met. Through recursive partitioning analysis, an algorithm of fewest questions needed to capture the most high-risk individuals was developed. The results were validated in 5,335 individuals undergoing colonoscopy at five private endoscopy centers and tested in 285 carriers of mismatch repair mutations associated with LS. About 17.7% and 20.0% of individuals were classified as high-risk in the development and validation cohorts, respectively. Recursive partitioning revealed three questions that were most informative for identifying high-risk patients: (i) "Do you have a first-degree relative with CRC or LS-related cancer diagnosed before age 50?" (ii) "Have you had CRC or polyps diagnosed before age 50?" (iii) "Do you have > or =3 relatives with CRC?" When asked successively, these questions identified 77% of high-risk individuals in both cohorts and 271 of 285 (95%) of mutation carriers. Approximately one in five individuals undergoing colonoscopy would benefit from further risk assessment. We developed a simple, three-question CRC Risk Assessment Tool to identify the majority of patients who require additional assessment and possible genetic evaluation.