Yusaku Shimamoto1, Shingo Ishiguro2, Yoji Takeuchi1, Shin-Ichi Nakatsuka3, Hiroshi Yunokizaki4, Yasumasa Ezoe4, Takeshi Nakajima5, Kenshi Matsuno1, Hiroko Nakahira1, Kumiko Tanaka6, Ryu Ishihara1, Tetsuji Takayama6, Teruhiko Yoshida7, Hideki Ishikawa8. 1. Department of Gastrointestinal Oncology, Osaka International Cancer Institute, Osaka, Japan. 2. Pathology & Cytology Laboratories Japan, Tokyo, Japan. 3. Department of Diagnostic Pathology and Cytology, Osaka International Cancer Institute, Osaka, Japan. 4. Ishikawa Gastroenterology Clinic, Osaka, Japan. 5. Department of Clinical Genetics, The Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan. 6. Department of Gastroenterology and Oncology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan. 7. Department of Genetic Medicine and Services, National Cancer Center Research Institute, Tokyo, Japan. 8. Ishikawa Gastroenterology Clinic, Osaka, Japan; Department of Molecular-Targeting Cancer Prevention, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Abstract
BACKGROUND AND AIMS: Gastric neoplasms in patients with familial adenomatous polyposis (FAP) occur at a high rate and can cause death. The endoscopic findings of gastric neoplasms in these patients are characteristic but not well recognized. To identify the relevant characteristics to enable early detection, we retrospectively investigated endoscopic findings of gastric neoplasms in patients with FAP and then compared the clinical, histopathologic, and genetic features among subgroups. METHODS: Of 234 patients with 171 pedigrees at 2 institutes, 56 cases (24%, 133 gastric neoplasms) with 44 pedigrees were examined. Immunostaining was performed for histopathologic evaluation by 1 blinded pathologist. According to the endoscopic findings, gastric neoplasms were divided into 4 types based on location (L: antrum and pylorus, UM: the rest of the stomach) and color (W: white, T: translucent, R: reddish) and their clinicopathologic features examined. RESULTS: Of the cases, 93% could be classified into a single type. Among histologic phenotypes, high-grade dysplasia was present in 26% (type L), 41% (type UM-W), 0% (type UM-T), and 22% (type UM-R). The immunologic phenotype comprised the gastric type in 69% (93% in Type UM) and the intestinal phenotype, including the mixed type, in 31% (61% in type L). Moreover, 96% of patients had concurrent duodenal neoplasms. Adenomatous polyposis coli gene status was identified in 93% of patients; the pathogenic variant was detected in 98% but did not influence any endoscopic features. CONCLUSIONS: Gastric neoplasms in patients with FAP were stratified into 4 types according to their endoscopic findings. The endoscopic phenotype was related to the histopathologic phenotype but not to germline variants.
BACKGROUND AND AIMS: Gastric neoplasms in patients with familial adenomatous polyposis (FAP) occur at a high rate and can cause death. The endoscopic findings of gastric neoplasms in these patients are characteristic but not well recognized. To identify the relevant characteristics to enable early detection, we retrospectively investigated endoscopic findings of gastric neoplasms in patients with FAP and then compared the clinical, histopathologic, and genetic features among subgroups. METHODS: Of 234 patients with 171 pedigrees at 2 institutes, 56 cases (24%, 133 gastric neoplasms) with 44 pedigrees were examined. Immunostaining was performed for histopathologic evaluation by 1 blinded pathologist. According to the endoscopic findings, gastric neoplasms were divided into 4 types based on location (L: antrum and pylorus, UM: the rest of the stomach) and color (W: white, T: translucent, R: reddish) and their clinicopathologic features examined. RESULTS: Of the cases, 93% could be classified into a single type. Among histologic phenotypes, high-grade dysplasia was present in 26% (type L), 41% (type UM-W), 0% (type UM-T), and 22% (type UM-R). The immunologic phenotype comprised the gastric type in 69% (93% in Type UM) and the intestinal phenotype, including the mixed type, in 31% (61% in type L). Moreover, 96% of patients had concurrent duodenal neoplasms. Adenomatous polyposis coli gene status was identified in 93% of patients; the pathogenic variant was detected in 98% but did not influence any endoscopic features. CONCLUSIONS: Gastric neoplasms in patients with FAP were stratified into 4 types according to their endoscopic findings. The endoscopic phenotype was related to the histopathologic phenotype but not to germline variants.