Nowak Jonathan A, Yurgelun Matthew B, Bruce Jacqueline L, Rojas-Rudilla Vanesa, Hall Dimity L, Shivdasani Priyanka, Garcia Elizabeth P, Agoston Agoston T, Srivastava Amitabh, Ogino Shuji, Kuo Frank C, Lindeman Neal I, Dong Fei
Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Center for Medical Genetics and Prevention, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts; Department of Medical Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts.
J Mol Diagn. 2017 Jan;19(1):84-91. doi: 10.1016/j.jmoldx.2016.07.010. Epub 2016 Nov 15.
Mismatch repair protein deficiency (MMR-D) and high microsatellite instability (MSI-H) are features of Lynch syndrome-associated colorectal carcinomas and have implications in clinical management. We evaluate the ability of a targeted next-generation sequencing panel to detect MMR-D and MSI-H based on mutational phenotype. Using a criterion of >40 total mutations per megabase or >5 single-base insertion or deletion mutations in repeats per megabase, sequencing achieves 92% sensitivity and 100% specificity for MMR-D by immunohistochemistry in a training cohort of 149 colorectal carcinomas and 91% sensitivity and 98% specificity for MMR-D in a validation cohort of 94 additional colorectal carcinomas. False-negative samples are attributable to tumor heterogeneity, and next-generation sequencing results are concordant with analysis of microsatellite loci by PCR. In a subset of 95 carcinomas with microsatellite analysis, sequencing achieves 100% sensitivity and 99% specificity for MSI-H in the combined training and validation set. False-positive results for MMR-D and MSI-H are attributable to ultramutated cancers with POLE mutations, which are confirmed by direct sequencing of the POLE gene and are detected by mutational signature analysis. These findings provide a framework for a targeted tumor sequencing panel to accurately detect MMR-D and MSI-H in colorectal carcinomas.
错配修复蛋白缺陷（MMR-D）和高微卫星不稳定性（MSI-H）是林奇综合征相关结直肠癌的特征，对临床管理具有重要意义。我们评估了一个靶向二代测序 panel 根据突变表型检测 MMR-D 和 MSI-H 的能力。使用每兆碱基总突变数>40 或每兆碱基重复序列中>5 个单碱基插入或缺失突变的标准，在 149 例结直肠癌的训练队列中，测序对通过免疫组化检测的 MMR-D 实现了 92%的敏感性和 100%的特异性，在另外 94 例结直肠癌的验证队列中对 MMR-D 的敏感性为 91%，特异性为 98%。假阴性样本归因于肿瘤异质性，并且二代测序结果与通过 PCR 分析微卫星位点的结果一致。在 95 例进行微卫星分析的癌组织子集中，测序在联合训练和验证集中对 MSI-H 实现了 100%的敏感性和 99%的特异性。MMR-D 和 MSI-H 的假阳性结果归因于具有 POLE 突变的超突变癌症，这通过 POLE基因的直接测序得到证实，并通过突变特征分析检测到。这些发现为靶向肿瘤测序 panel 准确检测结直肠癌中的 MMR-D 和 MSI-H 提供了一个框架。
