Is gastric cancer a new indication for surveillance colonoscopy? Colon cancer is increased in gastric cancer patients]

BACKGROUND/AIMS: It has been reported that the risk of gastric polyp is increased in various colonic polyposis syndromes or in series of patients with sporadic colonic polyps. However, there are only a few large case controlled studies of colon cancer incidence in gastric cancer patients who underwent colonoscopy. The aims of this study were to determine the incidence of colorectal neoplasm and to evaluate the necessity of colonoscopic surveillance in patients with gastric cancer. METHODS: We performed colonoscopy in 105 patients with gastric cancer who agreed to undergo colonoscopy before or after 6 months from gastric resection between January 2002 and December 2004 in Kangbuk Samsung hospital. As a control group, 269 consecutive, age and sex matched patients without gastric neoplasm on gastroscopy who underwent colonoscopy within 6 months for the evaluation of various gastrointestinal symptoms during the year 2004 were included. Endoscopic reports and pathological results were reviewed retrospectively. RESULTS: In the patient group, adenomatous polyps were diagnosed in 24/105 patients (22.9%) and colorectal adenocarcinoma in 10/105 patients (9.5%). In the control group, adenomatous polyps were diagnosed in 78/269 patients (29.0%) and colorectal adenocarcinoma in 2/269 patients (0.7%). The incidence of colorectal adenocarcinoma between the patient group and control group showed significant differences (odds ratio 11.04, p=0.003). CONCLUSIONS: The risk of colorectal adenocarcinoma increases significantly in patients with gastric cancer. We suggest that the patients with gastric cancer might carry a high risk for colorectal cancer whom require surveillance colonoscopy.