The prevalence of colorectal neoplasia in patients with gastric cancer: A korean association for the study of intestinal disease (KASID) study

GOALS: The goal of this study was to determine the prevalence of colorectal neoplasia, using colonoscopy surveillance, in a cohort of patients with gastric cancers. BACKGROUND: The association between gastric cancer and colorectal cancer has been conflicting. STUDY: A total of 543 patients (males, 362; females, 181) with gastric cancer were matched with 2 persons from the population without a diagnosis of gastric cancer as confirmed by endoscopy according to age (±2y), sex, date of colonoscopy examination (±2wk), and endoscopist. Main Outcome was the prevalence of colorectal neoplasia diagnosed by colonoscopy. RESULTS: A significantly higher colorectal cancer prevalence was found in the gastric cancer group, that is, 19 of 543 (3.5%) versus 14 of 1086 (1.3%; P<0.001). The odds of developing colorectal cancer were higher in the presence of gastric cancer (odds ratios, 3.46; 95% confidence interval: 1.51-7.91). Four of the 119 (3.4%) gastric cancer patients below 50 years of age had colorectal cancer in contrast with no cases in the matched controls. The prevalence of colorectal adenoma was higher in the gastric cancer group, with a prevalence of 215 in 543 (39.6%) versus 311 in 1086 (28.6%; P<0.001). The risk of adenoma was also greater among gastric cancer patients (odds ratios, 1.76; 95% confidence interval: 1.34-2.25). CONCLUSIONS: Our data reveal a higher prevalence and risk of colorectal cancer in patients diagnosed with gastric cancer, particularly in patients below 50 years of age. Additional studies are needed to explore the geographical differences in the association between gastric cancer and colon cancer.