Predictors of Isolated Advanced Proximal Neoplasia of Colon: The Kasid Prospective Multicenter Study

Predictors of Isolated Advanced Proximal Neoplasia of Colon: The Kasid Prospective Multicenter Study Hyun Soo Kim, Won Ho Kim, Tae Il Kim, Young-Ho Kim, Hyo Jong Kim, Suk-Kyun Yang, Seung-Jae Myung, Jeong-Sik Byeon, Moon Sung Lee, Il Kwon Jung, Sung-Ae Jung, Moon Kwan Chung, Yoon Tae Jeen, Jai Hyun Choi, Hwang Choi, Dong Soo Han, Jae Suk Song Background: Although advanced adenomatous polyp is an ideal target of colorectal cancer screening, isolated proximal neoplasia without distal pathology would have been missed on a flexible sigmoidoscopy, an effective colorectal cancer screening technique. The aim of the study is to identify predictors of isolated advanced proximal neoplasia of colon. Methods: Data were prospectively collected from the 17,200 patients who presented for colonoscopy in 12 tertiary endoscopic centers. Information gathered included demographic characteristics including body mass index (BMI), endoscopic findings, histology, drug history of aspirin/ NSAID, and known risk factors for colorectal neoplasia. We compared the patients with isolated proximal advanced neoplasia with the patients without colon neoplasia. We defined advanced neoplasia as adenocarcinoma, high-grade dysplasia, villous polyps, or adenomas more than 11 mm. Results: Isolated advanced proximal neoplasia was found in 371 (2.2%) patients, and 6234 (36.2%) patients as a control group had no colon neoplasia. While patients older than 65 year had a risk for isolated advanced proximal neoplasia (OR Z 1.38: 95% CI Z 1.07-1.78; p Z 0.015), male gender, obesity (BMI; O27), those who took a daily aspirin or NSAID, and a family history of colorectal cancer were not associated with an increased risk of isolated advanced proximal neoplasia. Conclusion: Because age greater than 65 year increased the risk of finding isolated proximal advanced neoplasia, colonoscopy rather than flexible sigmoidoscopy should be the first consideration as a colorectal screening in the older population.