Test Code PIK3T PIK3CA Mutation Analysis, Tumor
Test Down Notes
Effective 09/17/2025: This test is temporarily unavailable due to reagent issues. Please send all samples received during this period to the laboratory for stabilization and testing - DO NOT SWTICH TEST CODE OR HOLD. Please send additional questions to tech support. See test notification here
Necessary Information
A pathology report (final or preliminary), at minimum containing the following information, must accompany specimen for testing to be performed:
1. Patient name
2. Block number-must be on all blocks, slides, and paperwork (can be handwritten on the paperwork)
3. Tissue collection date
4. Source of the tissue
Specimen Required
This assay requires at least 20% tumor nuclei.
-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 108 mm(2)
-Minimum amount of tumor area: tissue 18 mm(2)
-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei
-Tissue fixation: formalin-fixed paraffin-embedded (FFPE), non-decalcified
Preferred: Submit 2, if available, of the following specimens.
Acceptable: Submit at least one of the following specimens.
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.
Specimen Type: Tissue slide
Slides: 1 Hematoxylin and eosin-stained and 10 unstained
Collection Instructions:
Submit the followings slides:
1 Slide stained with hematoxylin and eosin
AND
10 Unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block.
Additional Information: Unused unstained slides will not be returned.
Secondary ID
614801Useful For
Identification of hormone receptor positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) advanced breast cancer tumors that may be eligible for treatment with targeted kinase inhibitor therapy (eg, alpelisib).
Testing Algorithm
When this test is ordered, slide review will always be performed at an additional charge.
Method Name
Polymerase Chain Reaction (PCR)
Reporting Name
PIK3CA Mutation Analysis, TumorSpecimen Type
VariesSpecimen Minimum Volume
See Specimen Required
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Varies | Ambient (preferred) | |
Refrigerated |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided
Day(s) Performed
Monday through Friday
Report Available
8 to 12 daysPerforming Laboratory

Test Classification
This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81309
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PIK3T | PIK3CA Mutation Analysis, Tumor | 60034-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
616654 | Result Summary | 50397-9 |
616655 | Result | 82939-0 |
616656 | Interpretation | 69047-9 |
616657 | Additional Information | 48767-8 |
616658 | Specimen | 31208-2 |
616659 | Source | 31208-2 |
616660 | Tissue ID | 80398-1 |
616661 | Released By | 18771-6 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Additional Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
SLIRV | Slide Review in MG | No, (Bill Only) | Yes |