PIK3CA encodes one of the catalytic subunits of phosphatidylinositol 3-kinase (PI3K), a lipid kinase involved in PI3K-AKT-mTOR signaling. PIK3CA mutations resulting in increased PI3K catalytic activity and oncogenic transformation are well-described in many types of cancer. The detection of these mutations can have important treatment implications. Alpelisib (Piqray) is FDA-approved for the treatment of postmenopausal patients with HR+, HER2-, PIK3CA-mutated metastatic breast cancer following progression on or after endocrine-based therapy. This DNA test is performed by targeted next-generation sequencing (NGS) and will detect PIK3CA mutations within the sequenced regions of exons 2, 5, 6, 8, 10, 14, 19 and 21 (NM_006218). Commonly mutated codons covered by this assay include R88, N345, C420, E542, E545, Q546 and H1047. See below for more information regarding sequenced regions of PIK3CA.
Interpretive report provided.
For formalin-fixed, paraffin-embedded tissue, a block containing an area with a high percentage of neoplastic cells (for micro-/macro-dissection) is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted; however, these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature. A Diff-Quik or Papanicolaou stained aspirate smear (preferable containing a high percentage and overall amount of neoplastic cells) is also acceptable. Store at room temperature
By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.