title: Discordance Between Cobas BRAF V600 Testing and VE1 Immunohistochemistry in a Melanoma Patient With Bone Marrow Metastases.
abstract: False negative result remains an ongoing problem in direct gene sequencing of cancers. It is important to use the appropriate mutation detection method most appropriate to each circumstance and the available tissue. Here, we report a patient with melanoma of unknown primary with metastases to spleen and bone marrow, who was tested negative for Cobas BRAF V600E mutation, whose cancer progressed on antiprogrammed death 1 (PD1) receptor monoclonal antibody therapy. Subsequent VE1 immunohistochemistry was positive for BRAF V600E mutation, and the tumor responded dramatically to v-Raf murine sarcoma viral oncogene homolog B (BRAF)/Mitogen-activated protein kinase inhibitor combination therapy. This demonstrates how alternative BRAF testing methodology could produce results that can influence treatment choice and the outcome.
authors.affiliation: *Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC; †Memorial Sloan Kettering Cancer Center, New York, NY; and ‡George Washington University, Washington, DC.
authors.forename: Suthee
authors.initials: S
authors.lastname: Rapisuwon
authors.forename: Klaus J
authors.initials: KJ
authors.lastname: Busam
authors.forename: Kellie
authors.initials: K
authors.lastname: Parks
authors.forename: Paul B
authors.initials: PB
authors.lastname: Chapman
authors.forename: Elsie
authors.initials: E
authors.lastname: Lee
authors.forename: Michael B
authors.initials: MB
authors.lastname: Atkins
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D019046:Bone Marrow Neoplasms / Q000235:genetics / Q000556:secondary*; D004252:DNA Mutational Analysis / Q000379:methods; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008545:Melanoma / Q000235:genetics* / Q000556:secondary*; D009382:Neoplasms, Unknown Primary / Q000235:genetics*; D048493:Proto-Oncogene Proteins B-raf / Q000032:analysis / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf