Tu1505 THE PREVALENCE OF COLONIC POLYPS AND COLORECTAL CANCER IN PATIENTS WITH GASTRIC NEOPLASM: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Gastric adenomas are neoplastic with similar microscopic findings to those seen in colonic adenomas. Around 8-59% of gastric adenomas are associated with synchronous gastric carcinoma and hence repeat upper endoscopic surveillance after one year is usually recommended. On the other hand, the data has been scarce and inconsistent with regards to their association with colonic polyps and colorectal cancer. We aimed to analyze the previously published literature evaluating the association between gastric neoplasm and colonic polyps and colorectal cancer. We conducted a systematic literature search in PubMed, MEDLINE, EMBASE, and Cochrane databases from inception through November 2019 to identify studies evaluating the association between gastric adenomas or gastric neoplasms and colonic polyps, advanced adenomas, and colorectal cancer. Gastric neoplasm was universally defined in these studies as either malignancy or adenoma. Studies were examined, and relevant data was extracted and analyzed using Comprehensive Meta-Analysis (CMA), version 3 software. A random-effect meta-analysis approach was used to pool the data and an odds ratio (OR) was calculated for the overall effect estimate. A total of 134,317 patients from seven studies were identified and included in our analysis. The pooled OR for colonic polyps among patients with gastric neoplasm was 1.958 (95% CI:1.511-2.538; p=0.0001) compared to controls with modest heterogeneity (I2 =21.025%). (Fig 1a) Similarly, the pooled OR for advanced colonic adenomas in patients with gastric neoplasm was 2.129 (95% CI: 1.582–2.866; p=0.0001) compared to controls. (Fig 1b)Individuals with gastric neoplasm had an OR of 4.71 (95% CI: 1.296–17.139; p=0.019) for having synchronous colonic adenocarcinoma compared to controls. (Fig 1c)A subgroup analysis including only patients with gastric adenoma found an OR of 1.79 (95% CI: 1.341-2.403; P=0.0001) for having associated colonic polyps compared to controls. (Fig 2) No publication bias was found using Egger’s regression intercept. Our study findings indicate that the prevalence of colorectal polyps, advanced adenomas, and adenocarcinoma is significantly higher in patients with gastric adenomas and/or gastric malignancy compared to the general population. As such, screening colonoscopy may be justified in these patients following the diagnosis of gastric neoplasm for early detection and timely management of colonic neoplasia, particularly for patients over the age of 50 years.Fig 2Forrest plot, the pooled odds ratio evaluating the association between gastric adenoma and colonic polyps.View Large Image Figure ViewerDownload Hi-res image Download (PPT)