Kanemitsu Kiyonori, Kawasaki Kentaro, Nakamura Mitsutoshi, Li Dong, Yasuda Takashi, Kuroda Daisuke, Yokozaki Hiroshi, Kamigaki Takashi, Kuroda Yoshikazu
Department of Gastroenterological Surgery, Kobe University Graduate School of Medical Sciences, Japan.
Hepatogastroenterology. 2007 Dec;54(80):2410-4.
BACKGROUND/AIMS: A family history of cancer raises the risk of gastric cancer. Microsatellite instability (MSI) is frequently observed in hereditary non-polyposis colorectal cancer (HNPCC), and gastric cancer is the most frequent extra-colonic cancer among HNPCC patients. The relationship between gastric cancer and MSI is controversial. The purpose of this study was to identify the relationship between MSI incidence and gastric cancer in patients with a family history of cancer.
MSI incidence was examined at 5 microsatellite loci and hMLH1 and hMSH2 protein expression was examined by immunohistochemical analysis in 30 gastric cancer patients with family histories of cancer (familial group) and 37 gastric cancer patients without any family history of cancer (sporadic group).
The incidence of high-frequency MSI (MSI-H) in the familial group was 33.3% (10/30) and in the sporadic group it was 5.4% (2/37) (p < 0.05). The incidence of lack of at least one mismatch repair (MMR) protein was 66.7% (8/12) in MSI-H cases, which was significantly higher than in low-frequency MSI (MSI-L) cases and microsatellite stable (MSS) cases.
MSI may play an important role in the development of gastric cancer in individuals with a family history of cancer and it is induced by a deficiency in MMR protein expression.
背景/目的：癌症家族史会增加患胃癌的风险。微卫星不稳定性（MSI）在遗传性非息肉病性结直肠癌（HNPCC）中经常被观察到，并且胃癌是HNPCC患者中最常见的结肠外癌症。胃癌与MSI之间的关系存在争议。本研究的目的是确定有癌症家族史的患者中MSI发生率与胃癌之间的关系。
对30例有癌症家族史的胃癌患者（家族组）和37例无任何癌症家族史的胃癌患者（散发组），检测5个微卫星位点的MSI发生率，并通过免疫组化分析检测hMLH1和hMSH2蛋白表达。
家族组高频MSI（MSI-H）的发生率为33.3%（10/30），散发组为5.4%（2/37）（p<0.05）。在MSI-H病例中，至少一种错配修复（MMR）蛋白缺失的发生率为66.7%（8/12），显著高于低频MSI（MSI-L）病例和微卫星稳定（MSS）病例。
MSI可能在有癌症家族史的个体胃癌发生中起重要作用，并且它是由MMR蛋白表达缺陷诱导的。
