PDGFRA by Sequencing

Formalin-fixed, paraffin-embedded tissue blocks; fixed in 10% neutral-buffered formalin for at least 6 hours, and not more than 48 hours. Tissue should be prepared in sections between 4 to 6 microns thick. EDTA decal specimens and cytology smears are acceptable.

The PDGFRA gene encodes for the protein Platelet-derived growth factor alpha (PDGFRA). Mutations, insertions, deletions, fusions and genomic amplification of PDGFRA lead to its activation in several tumor types: 5~10% of gastrointestinal stromal tumors (GISTs) have PDGFRA activating mutations and these mutations are mutually exclusive from KIT mutations (PMID: 20023271). Activating mutations in PDGFRA have also been been reported in subset of patients with melanoma, sarcomas, NSCLC, gliomas, and certain types of myeloid stem cell neoplasm.

The mutations in KIT and PDGFRA in GIST result in expression of mutant proteins with constitutive tyrosine kinase activity. Testing for KIT and PDGFRA mutations should be performed if TKIs are considered as part of the treatment plan since the presence of mutations (or absence of mutations) in specific regions of the KIT and PDGFRA genes are correlated with response (or lack of a response) to specific TKIs. Metastatic disease with acquired drug resistance is usually the result of secondary, imatinib-resistant mutations in KIT or PDGFRA.

Pathology Report

Room temperature, express mail if not on courier service

Tissue not verified for the presence of tumor and specimens fixed in fixatives other than formalin are not acceptable. Samples <10% tumor burden will not be tested, as false negative results cannot be ruled out. Surgical pathology report should be included. Acid decalcification compromises the specimen quality and is not acceptable.

10 years FFPE

Clinical indication and specimen source is required for the assay.