Test Id : PIK3T
PIK3CA Mutation Analysis, Tumor
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Method Name
A short description of the method used to perform the test
Polymerase Chain Reaction (PCR)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
PIK3CA
PIK3CA mutation
Breast cancer
Alpelisib
Kinase inhibitor therapy
PIQRAY
Oncology
Tumor testing
C420R
E542K
E545A
E545D
E545G
E545K
Q546E
H1047L
H1047R
H1047Y
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Specimen Type
Describes the specimen type validated for testing
Varies
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
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
This assay requires at least 20% tumor nuclei.
The amount of tissue needed is dependent on a variety of preanalytical factors (eg, cellularity, ischemic time, fixation).
The FFPE input required is equivalent to a 4 to 5 micron slide thickness with a total tumor surface area of 100 mm(2). This can be created by combining material from multiple slides from one tissue block.
Preferred:
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block.
Acceptable:
Specimen Type: Tissue slide
Slides: 1 stained and 10 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
See Specimen Required
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Specimens that have been decalcified (all methods) Specimens that have not been formalin-fixed, paraffin-embedded | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Useful For
Suggests clinical disorders or settings where the test may be helpful
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
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
More than 70% of breast cancers are hormone receptor (HR) positive and human epidermal growth factor receptor 2 (HER2) negative (HR+/HER2-). Approximately 40% of patients with HR+/HER2- advanced breast cancer have activating mutations in the gene PIK3CA, inducing hyperactivation of the alpha isoform (p110alpha) of phosphatidylinositol 3-kinase, a key upstream component of the PI3K pathway. Mutations in PIK3CA are associated with tumor growth, resistance to endocrine therapy, and a poor overall prognosis.
Patients with HR+/HER2- advanced breast cancer identified to have a PIK3CA mutation may be eligible for treatment with targeted kinase inhibitor therapy (eg, alpelisib).
This test uses DNA extracted from tumors to evaluate for the presence of 10 clinically actionable PIK3CA mutations:
E542K (c.1624G>A)
E542K (c.1633G>A)
E545D (c.1635G>T)
E545G (c.1634A>G)
E545A (c.1634A>C)
H1047Y (c.3139C>T)
C420R (c.1285C>T)
Q546E (c.1636C>G)
H1047L (c.3140A>T)
H1047R (c.3140A>G)
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided
Interpretation
Provides information to assist in interpretation of the test results
The interpretation of molecular biomarker results includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A negative (wildtype) result does not rule out the presence of a mutation that may be present but below the limits of detection of this assay. It also does not rule out the presence of other types of alterations in the PIK3CA gene outside those that the assay was designed to detect.
This test is not designed to differentiate between somatic and germline alterations. Additional testing may be necessary to clarify the significance of results if there is a potential hereditary risk.
Not all tumors that have PIK3CA mutations will respond to targeted therapies.
Rare genetic alterations exist that could lead to false-negative or false-positive results.
Test results should be interpreted in context of clinical findings, tumor sampling, and other laboratory data. If results obtained do not match other clinical or laboratory findings, please contact the laboratory for possible interpretation. Misinterpretation of results may occur if the information provided is inaccurate or incomplete.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Bachman K, Argani P, Samuels Y, et al: The PIK3CA gene is mutated with high frequency in human breast cancers. Cancer Biol Ther. 2004 Aug;3(8):772-775
2. Andre F, Ciruelos EM, Rubovszky G, et al: Alpelisib for PIK3CA-mutated, hormone receptor-positive advanced breast cancer. N Engl J Med. 2019 May 16;380(20):1929-1940
3. Andre F, Ciruelos EM, Juric D, et al: Alpelisib plus fulvestrant for PIK3CA-mutated, hormone receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer: final overall survival results from SOLAR-1. Ann Oncol. 2021 Feb;32(2):208-217
Method Description
Describes how the test is performed and provides a method-specific reference
Microscopic examination is performed by a pathologist to identify areas of tumor for enrichment by macrodissection. Testing is performed on invasive tissue only. Other tissue components, such as ductal carcinoma in situ (DCIS), are excluded.
A polymerase-chain reaction (PCR)-based assay employing real-time PCR and allele-specific PCR technologies is used to test for 10 mutations within PIK3CA (C420R, E542K, E545A, E545D, E545G, E545K, Q546E, H1047L, H1047R, and H1047Y).(Package insert: therascreen PIK3CA RGQ PCR Kit. Qiagen; 05/2019)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Friday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
81309
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| PIK3T | PIK3CA Mutation Analysis, Tumor | 60034-6 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 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 |