Cell-Free DNA PIK3CA Test, Blood
Use
The Cell-Free DNA PIK3CA Test is used for identifying HR+/HER2- advanced breast cancer tumors that may be eligible for treatment with targeted kinase inhibitor therapy, such as alpelisib. Approximately 40% of patients with HR+/HER2- advanced breast cancer harbor activating mutations in the PIK3CA gene, which can induce hyperactivation of the alpha isoform of the phosphatidylinositol 3-kinase, contributing to tumor growth, resistance to endocrine therapy, and poor prognosis. This test detects 10 clinically actionable PIK3CA mutations.
Special Instructions
Not provided.
Limitations
A negative result does not exclude the presence of undetected mutations below the limits of assay detection or other alterations not evaluated by this test. This test cannot differentiate between somatic and germline alterations and is not validated for monitoring therapy response or early tumor detection. Misinterpretation may result from inaccurate or incomplete clinical data. It cannot assure responsiveness to targeted therapies, and rare genetic alterations can lead to false results.
New York Approved
Methodology
PCR-based (Real-time PCR and allele-specific PCR)
Biomarkers
LOINC Codes
- 60034-6 - PIK3CA gene Mut Anl Bld/T
- 50397-9 - Mol dx interp Bld/T Ql
- 82939-0 - Genetic variant details Bld/T
- 69047-9 - Geneticist review
- 48767-8 - Annotation comment Imp
- 31208-2 - Specimen source
- 18771-6 - Provider signing name
Result Turnaround Time
5-10 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
20 mL
Minimum Volume
10 mL
Container
Streck Black/Tan Top Tube Kit
Collection Instructions
Only blood collected in Streck cfDNA tubes will be accepted. Use two 10-mL Streck cell-free DNA blood collection tubes.
Storage Instructions
Store samples ambient (preferred) or refrigerated. Maintain for up to 7 days.
Causes for Rejection
Evaluation for suitability is done on all specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 7 days |