Furlan D, Tibiletti M G, Taborelli M, Albarello L, Cornaggia M, Capella C
Department of Clinical and Biological Sciences, University of Pavia at Varese, Italy.
Ann Oncol. 1998 Aug;9(8):901-6. doi: 10.1023/a:1008307611407.
Microsatellite instability (MI) is a biological characteristic of most tumors involved in hereditary non-polyposis colorectal cancer (HNPCC). This disease appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. At least five human genes participate in MMR. MI also occurs in 10%-15% of sporadic colorectal cancers. Because MI detection has been suggested as an alternative diagnostic tool for identification of HNPCC families, in this study we analyzed the MI pattern in 100 consecutive colorectal carcinomas in order to correlate them with the clinicopathologic features and family histories of the patients.
A series of 100 colorectal cancers was evaluated for MI with 10 polymerase chain reaction primer sets. Instability results were compared with family history and other clinical and biological characteristics.
MI was detected in 36 of 100 cancers, 27 of which showed low instability and nine a high instability. The low- and high-instability cases showed similar clinicopathological characteristics, and significantly positive associations were observed between MI and mucinous histological type (P = 0.0001) and MI and peritumoral lymphocytic infiltration (P = 0.01). A single HNPCC family was identified in the high-grade MI group, while two families belonged to the MI-negative group.
Our data suggest that MI screening is probably not an efficient strategy for identifying HNPCC cases. MI does, however, appear capable of defining a category of colorectal cancers with favourable prognostic features and should be investigated at least in all cases of mucinous adenocarcinomas.
微卫星不稳定性（MI）是大多数遗传性非息肉病性结直肠癌（HNPCC）相关肿瘤的生物学特征。这种疾病似乎是由错配修复（MMR）基因的种系突变引起的，这些基因负责修复单碱基对错配。至少有五个人类基因参与错配修复。MI也出现在10%-15%的散发性结直肠癌中。由于MI检测已被建议作为识别HNPCC家系的一种替代诊断工具，因此在本研究中，我们分析了100例连续结直肠癌的MI模式，以便将它们与患者的临床病理特征和家族史相关联。
使用10套聚合酶链反应引物对100例结直肠癌进行MI评估。将不稳定性结果与家族史以及其他临床和生物学特征进行比较。
100例癌症中有36例检测到MI，其中27例显示低不稳定性，9例显示高不稳定性。低不稳定性和高不稳定性病例显示出相似的临床病理特征，并且在MI与黏液组织学类型之间（P = 0.0001）以及MI与肿瘤周围淋巴细胞浸润之间（P = 0.01）观察到显著的正相关。在高等级MI组中鉴定出一个HNPCC家系，而在MI阴性组中有两个家系。
我们的数据表明，MI筛查可能不是识别HNPCC病例的有效策略。然而，MI似乎能够定义一类具有良好预后特征的结直肠癌，并且至少在所有黏液腺癌病例中都应进行研究。
