Related Experiment Video
Updated: May 11, 2026
Employing Digital Droplet PCR to Detect BRAF V600E Mutations in Formalin-fixed Paraffin-embedded Reference Standard Cell Lines
Published on: October 8, 2015
Detection of BRAF p.V600E Mutations in Melanoma by Immunohistochemistry Has a Good Interobserver Reproducibility
Cristi Marin1, Alain Beauchet, David Capper
1From units EA4340 (Drs Marin, Julié, and Emile) and EA4339 (Drs Beauchet, Zimmermann, and Saiag), Versailles SQY University, Boulogne, France; the Departments of Pathology (Drs Marin, Zimmermann, Julié, and Emile), Public Health (Dr Beauchet), and General and Oncologic Dermatology (Dr Saiag), Ambroise Pare Hospital, APHP, Boulogne, France; the Department of Neuropathology, Ruprecht-Karls-University Heidelberg, and Clinical Cooperation Unit Neuropathology, German Cancer Research Center (DKFZ), Heidelberg, Germany (Drs Capper and Deimling); and the Laboratory of Clinical and Experimental Pathology, Pasteur Hospital and Medical School, Nice Sophia University, Nice, France (Drs Ilie and Hofman).
Context:
Assessment of BRAF p.V600E mutational status has become necessary for treatment of patients with metastatic melanoma. Detection of p.V600E mutation by immunohistochemistry was recently reported in several tumor types.
Objective:
To evaluate the interobserver reproducibility of BRAF p.V600E detection by immunohistochemistry in melanoma.
Design:
Immunohistochemistry with VE1 antibody was performed on metastatic melanomas of 67 patients. Staining interpretation was performed on digital image virtual slides of tissue microarrays. The p.V600E status was determined by 7 pathologists from 3 European laboratories, blinded for other interpretations and for molecular biology results.
Results:
Melanomas had p.V600E (n = 30), p.V600K (n = 4), p.K601E (n = 1), p.600-601delinsE (n = 1), or no p.V600 mutations (n = 31). Staining of p.V600E within mutated cells was cytoplasmic and diffuse, and for each case the staining on the 3 tissue microarray cores was similar. In 53 cases (79.1%) the 7 pathologists had perfect concordance. Agreement of interobserver reproducibility was almost perfect (κ = 0.81 [0.77-0.85]). Only 2 false-positive responses (0.9%) were obtained. The specificities reported were 100% for 5 pathologists (two of whom previously trained for p.V600E interpretation), and 97% for 2 untrained pathologists.
Conclusions:
Detection of BRAF p.V600E mutation by immunohistochemistry in melanomas has an excellent interobserver reproducibility. Our results suggest that immunohistochemistry could be used as a first step for detection of BRAF p.V600E mutation, to identify patients with melanoma as candidates for BRAF inhibitors.
