Value of detection of DNA mismatch repair proteins deficiency by immunohistochemistry in predicting tumor microsatellite status

• Published in: Zhonghua bing li xue za zhi Vol. 44; no. 10; p. 704
• Main Authors: Qin, Yun, Liang, Liping, Zheng, Xingzheng, Zheng, Jie, Ye, Juxiang, Guo, Limei, Zhao, Feng, Shi, Xueying
• Format: Journal Article
• Language: Chinese
• Published: China 01-10-2015
• Subjects: Colorectal Neoplasms - genetics; DNA Mismatch Repair; DNA-Binding Proteins - deficiency; DNA-Binding Proteins - genetics; Humans; Immunohistochemistry; Microsatellite Instability; Polymerase Chain Reaction; Sensitivity and Specificity
• ISSN: 0529-5807
• DOI: 10.3760/cma.j.issn.0529-5807.2015.10.004

To evaluate the sensitivity and specificity of immunohistochemical (IHC) staining of DNA mismatch repair (MMR) protein for the screening of microsatellite instability (MSI) colorectal cancer (CRC).
A total of 255 CRC cases were studied, including 140 cases of routine paraffin-embedded tissue samples and 115 cases constructed on tissue microarray. Expressions of 4 MMR proteins including MHL1, MSH2, MSH6 and PMS2 were investigated by IHC. Negative protein expression was defined as complete absence of nuclear staining within tumor cells in the presence of positively labeled internal non-neoplastic cells. Focal staining was defined as the presence of staining in < 5% of the tumor cells. CRCs showing negative staining for any MMR proteins were interpreted as MMR deficient tumors. PCR-genescan MSI analysis was performed in each case by a five marker panel including Bat26, Bat25, NR-21, NR-24 and MONO-27.
Among the 140 CRCs with routine formalin-fixed paraffin embedded tissue sections, concordance rate between IHC a