The prevalence of colorectal polyps in patients with gastric cancer.

Abstract

549 Background: Gastric polyps are found frequently in various colonic polyposis syndromes. Genetic alterations of several genes occur in gastric adenomas and colorectal adenomas. However, it is unknown whether patients with gastric cancers are at higher risk for colorectal adenomas. Methods: We retrospectively reviewed the medical records in 112 patients with gastric cancers from January 2005 to December 2009. Patients who were diagnosed with gastric cancers and had colonoscopy within 6 months were compared to 220 sex and age-matched controls from 3,725 persons who underwent esophagogastroduodenoscopy and colonoscopy for screening at the Center for Health Promotion in Ewha Womans University Medical Center. High risk polyp was defined by any of the following: (1) the presence of three or more polyps; (2) polyp size at least 10mm; (3) high-grade dysplasia or adenocarcinoma confirmed by histopathologic examination. Otherwise the polyps were defined as low risk. Results: Mean age was 59 years-old and 70% was male in patients with gastric cancer. Overweight (BMI ≥ 23) was more common in control group (gastric cancer versus control: 56% and 69%, respectively, P = 0.025). Colorectal polyps were identified in 67 of 112 patients (59.8%) with gastric cancer and in 153 of 220 controls (69.5%). The prevalence of high risk polyps were numerically higher in the gastric cancer group than the control group, although not statistically significant (9% vs. 4%, P = 0.267). In contrast, the prevalence of low risk polyps were significantly frequent in the control group (91% vs. 96%, P = 0.024). The mean size and number of colorectal polyps were not different between the two groups. Adenocarcinoma was diagnosed from polyps in five patients (7%) with gastric cancer and four patients (2%) with control group (P = 0.190). Conclusions: The overall colorectal polyps, especially low risk polyps, were more prevalent in the control group. In contrast, high risk polyps and adenocarcinoma is more frequently found in patients with gastric cancer although not significant. Therefore, we suggest that colorectal polyps should be cautiously examined in patients with gastric cancer.