[Prevalence of colorectal adenoma is increased in patients with gastric adenoma]

It has been reported that patients with gastric cancer may be at increased risk of synchronous or metachronous colorectal cancer. However, the incidence of colorectal adenoma in patients with gastric adenoma has not been discussed earlier. The aims of this study were to investigate the incidence of colorectal adenoma and to evaluate the necessity of colonoscopic surveillance in patients with gastric adenoma.

We performed colonoscopy in 221 patients with gastric adenoma between January 2002 and June 2008. As a control group, 387 consecutive patients without gastric adenoma on gastroscopy who underwent colonoscopy were included. We retrospectively examined the endoscopic and colonoscopic findings as well as the clinicopathologic features.

Colorectal adenoma were diagnosed in 57.5% (127/221) of the gastric adenoma group and 38.0% (147/387) of the control group (p<0.001). Univariate analysis demonstrated that gender, age, past history of diabetes, and past history of gastric adenoma were associated with the risk of colorectal adenoma. Multivariate analysis demonstrated that gender (male, aOR 2.31, 95% CI 1.61-3.31), age (> or =50 years, aOR 2.47, 95% CI 1.53-4.01), past history of diabetes (aOR 2.35, 95% CI 1.32-4.20), and presence of gastric adenoma (aOR 1.63, 95% CI 1.13-2.36) appeared to be independent risk factors for colorectal adenoma.

The risk of colorectal adenoma increases significantly in patients with gastric adenoma. We suggest that colonoscopic surveillance may be necessary in patients with gastric adenoma.