Immunohistochemistry Versus Microsatellite Instability Testing in Phenotyping Colorectal Tumors

• DOI: 10.1200/jco.2002.20.4.1043
• Publication Date: 2017-02-24T08:46:55Z
• Authors: Noralane M. Lindor; Lawrence J. Burgart; Olga Leontovich; Richard M. Goldberg; Julie M. Cunningham; Daniel J. Sargent; Catherine Walsh-V...; Gloria M. Petersen; Michael D. Walsh; Barbara A. Leggett; Joanne P. Young; Melissa A. Barker; Jeremy R. Jass; John Hopper; Steve Gallinger; Bharati Bapat; Mark Redston; Stephen N. Thibodeau
• Keywords: Microsatellite Instability

PURPOSE: To compare microsatellite instability (MSI) testing with immunohistochemical (IHC) detection of hMLH1 and hMSH2 in colorectal cancer. PATIENTS AND METHODS: Colorectal cancers from 1,144 patients were assessed for DNA mismatch repair deficiency by two methods: MSI IHC gene products. High-frequency (MSI-H) was defined as more than 30% at least five markers; low-level (MSI-L) 1% to 29% loci unstable. RESULTS: Of tumors tested, 818 showed intact expression hMSH2. these, 680 stable (MSS), 27 MSI-H, 111 MSI-L. In all, 228 absence 98 expression: all MSI-H. CONCLUSION: protein products provides a rapid, cost-effective, sensitive (92.3%), extremely specific (100%) method screening defects. The predictive value normal an MSS/MSI-L phenotype 96.7%, the abnormal 100% MSI-H phenotype. Testing strategies must take into account acceptability missing some cases if only is performed.