Ito Tetsuya, Ishida Hideyuki, Suzuki Okihide, Chika Noriyasu, Amano Kunihiko, Ishibashi Keiichiro, Kamae Nao, Tada Yuhki, Akagi Kiwamu, Eguchi Hidetaka, Okazaki Yasushi
Department of Digestive Tract and General Surgery, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
Department of Clinical Genomics, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
J Anus Rectum Colon. 2020 Oct 29;4(4):165-173. doi: 10.23922/jarc.2020-026. eCollection 2020.
To investigate the prevalence and molecular characteristics of defective DNA mismatch repair (dMMR) in small-bowel carcinoma (SBC) in a Japanese-hospital population.
Immunohistochemistry was performed to evaluate the expression of MMR proteins (MLH1, MSH2, MSH6, and PMS2) in formalin-fixed paraffin-embedded sections prepared from surgically resected primary SBCs from 30 patients during March 2002 to March 2017. Genetic testing for Lynch syndrome was performed in patients who demonstrated MMR protein loss.
Two of 30 patients (6.7%) demonstrated concomitant loss of MSH2/MSH6 protein expression. Further genetic testing identified a pathogenic variant in one of these patients.
The prevalence of dMMR SBCs in a Japanese hospital-based population seems lower than that reported in previous studies. To determine whether dMMR SBCs might be strongly linked to Lynch syndrome, there is a need for further investigation with a larger sample size.
在一家日本医院的人群中，调查小肠癌（SBC）中DNA错配修复缺陷（dMMR）的患病率及分子特征。
对2002年3月至2017年3月期间30例手术切除的原发性SBC患者的福尔马林固定石蜡包埋切片进行免疫组织化学检测，以评估错配修复蛋白（MLH1、MSH2、MSH6和PMS2）的表达。对显示错配修复蛋白缺失的患者进行林奇综合征的基因检测。
30例患者中有2例（6.7%）表现为MSH2/MSH6蛋白表达同时缺失。进一步的基因检测在其中1例患者中发现了一个致病变异。
在日本以医院为基础的人群中，dMMR SBC的患病率似乎低于先前研究报道的患病率。为了确定dMMR SBC是否可能与林奇综合征密切相关，需要更大样本量的进一步研究。
