There are several key genes recurrently mutated in melanoma. Genomic DNA is isolated from formalin fixed paraffin embedded tissue and the DNA sequence of targeted regions of the BRAF, CD274, CDK4, HRAS, KIT, KRAS, NF1, and NRAS genes is determined using next-generation sequencing (NGS) technology.
For predictive purposes.
NCCN Guidelines for Melanoma strongly encourage testing for gene mutations that impact treatment options in metastatic melanoma. The Cancer Genome Atlas (TCGA) Network identified four main molecular subtypes of cutaneous melanoma:
- mutant BRAF
- mutant RAS (KRAS, NRAS, HRAS)
- mutant NF1
- triple wild-type (enriched in KIT mutations)
- Tissue (Preferred): Two (2) formalin-fixed, paraffin-embedded tissue/ fine needle aspirate (FFPE/FNA) blocks containing tumor tissue from recent surgery or biopsy or sixteen (16) 2x5 µm sections with accompanying H&E slide.
- Acceptable Alternative: One (1) formalin-fixed, paraffin-embedded tissue/fine needle aspirate (FFPE/FNA) block containing tumor tissue from recent surgery or biopsy or eight (8) 2×5 µm sections with accompanying H&E slide.
- Unacceptable: Specimens preserved in alternative (non-formalin) fixatives, decalcified specimens, fresh or frozen tissue.
Use cold pack for transport, making sure cold pack is not in direct contact with specimen. DO NOT FREEZE.