PIK3CA Mutation Analysis
Test Description
Sequence analysis of the mutation hotspot regions of exon 9 (codons 532 – 554) and exon 20 (codons 1011 – 1062) of the PIK3CA gene. The PIK3CA gene encodes the catalytic subunit p110 alpha of phosphatidylinositol 3-kinase (PI3K). Somatic mutations of PIK3CA have been observed in numerous cancers, including colon cancers, where they are associated with poor prognosis.
Indication
PIK3CA mutation status can be used for predicting prognosis and therapy response to novel PIK3CA-targeted therapies in development.
Methodology
PCR-based DNA Sanger sequencing
Sensitivity
20% mutant sequence in a background of wild type sequence or 40% tumor cells with heterozygous mutation in a background of normal cells.
Sample Requirements
- Four to six unstained recut slides of formalin-fixed, paraffin-embedded (FFPE) tissue sections
and - H&E-stained slide with areas to be tested marked by a circle and the percentage of tumor present in the circled areas indicated
Based on the sensitivity of the assay, the percentage of tumor present in the areas to be tested should be at least 40%.
Please provide a copy of the corresponding pathology report.
CPT Codes
83890 (DNA isolation), 83898, 83904, 83912
Additional charges will apply for tissue extraction.
The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.