NRASQ61R immunohistochemistry detects both NRASQ61R and KRASQ61R mutations in colorectal cancer
Journal
Pathology
Journal Volume
49
Journal Issue
4
Pages
387-390
Date Issued
2017
Author(s)
Abstract
The NRASQ61R monoclonal antibody (clone sp174) is a mutation-specific antibody that is increasingly being used to detect the NRASQ61R mutation in melanomas. This antibody has been reported to be highly correlated with the NRASQ61R mutation status in melanomas and follicular neoplasms of the thyroid gland. However, its utility in colorectal carcinoma (CRC) has remained largely unknown. In this study, we assessed the sensitivity, specificity, and diagnostic utility of NRASQ61R immunohistochemistry in a cohort consisting of tissue sections of 113 CRCs, which were molecularly profiled for the KRAS, NRAS, and BRAF mutations. Five CRCs tested positive for NRASQ61R immunohistochemistry. Four of these CRCs exhibited the NRASQ61R mutation and one exhibited the KRASQ61R mutation. All of the other 108 colorectal carcinomas lacking the NRASQ61R or KRASQ61R mutation tested negative for NRASQ61R immunohistochemistry. In the positively stained cases, we observed a diffuse staining pattern in >90% of the tumour cells with a moderate-to-strong intensity. By contrast, the staining was essentially entirely negative in cases negative for the NRASQ61R or KRASQ61R mutations. We concluded that although it cross-reacts with the mutant KRASQ61R protein, the NRASQ61R antibody is a useful diagnostic tool that assists in the molecular testing of CRCs and facilitates patient management. ? 2017 Royal College of Pathologists of Australasia
SDGs
Other Subjects
B Raf kinase; K ras protein; krasq61r protein; n ras protein; nrasq61r protein; protein; unclassified drug; guanosine triphosphatase; membrane protein; monoclonal antibody; NRAS protein, human; Article; codon; colorectal carcinoma; diagnostic value; exon; gene mutation; genotype; human; human tissue; immunohistochemistry; predictive value; sensitivity and specificity; wild type; cohort analysis; colorectal tumor; genetics; immunology; melanoma; metabolism; mutation; pathology; skin tumor; Antibodies, Monoclonal; Cohort Studies; Colorectal Neoplasms; GTP Phosphohydrolases; Humans; Immunohistochemistry; Melanoma; Membrane Proteins; Mutation; Skin Neoplasms
Publisher
Elsevier B.V.
Type
journal article