VE1 Antibody Is Not Highly Specific for the BRAF V600E Mutation in Thyroid Cytology Categories With the Exception of Malignant Cases

Abstract

VE1 immunocytochemistry in thyroid FNAC as a screening test for BRAF mutations is highly specific for malignant category cases but can be suboptimal due to its high false-positive rate for the nonmalignant cases.

BRAF V600E detection in cytological thyroid samples: A key component of the decision tree for surgical treatment of papillary thyroid carcinoma

“…As opposed to immunohistochemical techniques, which have been developed for the detection of the V600E mutation, the present technique is not subjected to the observer interpretation. Equivocal staining has indeed been reported for V600E immunodetection as well as false‐positive and false‐negative results …”

BRAF testing and thyroid FNA

“…The antibody appears to be best suited for applications with formalin‐fixed, paraffin‐embedded material such as cell blocks or surgical specimens and for cases diagnosed as PTC. Background and nonspecific staining and a lack of specificity for PTC in the Bethesda indeterminate categories have been reported with liquid‐based preparations or direct smears . In our experience, BRAF IHC does not perform well for routine use with these types of cytologic preparations.…”

“…Therefore, the commercially available V600E‐specific monoclonal antibody (clone VE1) for IHC is an attractive option for screening for the BRAF V600E mutation in thyroid lesions. Several studies have shown an excellent correlation between strong immunoreactivity for the V600E antibody and the presence of the corresponding mutation, with a sensitivity and specificity of 94% . The antibody appears to be best suited for applications with formalin‐fixed, paraffin‐embedded material such as cell blocks or surgical specimens and for cases diagnosed as PTC.…”

“…The Afirma GEC test has a high overall negative predictive value (93%) but a low specificity (52%) for the diagnosis of malignant thyroid nodules with indeterminate cytology, and some of the specific issues with this test have been discussed in previous commentaries …”

Lung Carcinoma Predictive Biomarker Testing by Immunoperoxidase Stains in Cytology and Small Biopsy Specimens: Advantages and Limitations

“…[57][58][59] Most of the experience with this antibody comes from studies using aspiration biopsies of thyroid carcinoma and melanoma, in which the antibody appears to work well on both alcohol-and formalin-fixed specimens, as well as in small biopsies and cytology material. [60][61][62] However, to our knowledge, there is no report of IPOX for BRAF in NSCLC cytology specimens.…”