β-Catenin activation in fundic gland polyps, gastric cancer and colonic polyps in families afflicted by ‘gastric adenocarcinoma and proximal polyposis of the stomach’ (GAPPS)

Aim To evaluate possible colon involvement in the ‘gastric adenocarcinoma and proximal polyposis of the stomach’ (GAPPS) gastrointestinal polyposis syndrome. Methods Prospective clinicopathological evaluation of two GAPPS families and expression of nuclear β-catenin, p53 and Ki67 measured by immunohistochemistry on endoscopic and surgical specimens from patients with GAPPS. Results Patients with the GAPPS phenotype were more frequently affected by colonic polyps than patients at risk within the same families (p Conclusions Similarities in expression markers in fundic gland and colonic polyps, together with an enrichment of colonic adenomas in family members affected by GAPPS phenotype compared with family members at risk, support mild colonic involvement of this rare cancer syndrome. Colonoscopic screening might be warranted. Clinical Trial Registration Number #09-C-0079; Results.