What are other Names for this Test? (Equivalent Terms)
- Phosphatidylinositol 3-Kinase, Catalytic, 110-KD, Alpha Mutation Analysis Test
- Phosphatidylinositol 3-Kinase, Catalytic, Alpha Polypeptide Mutation Analysis Test
- ptdIns-3-Kinase Subunit p110-alpha Mutation Analysis Test
What is PIK3CA Mutation Analysis Test? (Background Information)
- PIK3A mutation refers to an alteration in the PIK3A gene. It is associated with cancers of the lungs, ovaries, skin, and other systems
- The PIK3A gene gives instructions for the p110 protein. The p110 protein is a part of the PI3K enzyme. In fact, p110 is responsible for performing the enzymatic action of PI3K
- The PI3K enzyme participates in the communications systems between cells. It does this by chemically modifying signaling proteins through a process called phosphorylation
- Phosphorylation of signaling molecules by PI3K is necessary for the proper transmission of messages from other cells to the genetic machinery of the PI3K-containing cell, causing it to grow and divide
- Alterations in the PIK3A gene result in a modified p110 protein that is overactive. Because p110 performs the enzymatic action of PIK3A, an overactive p110 protein causes an overactive PIK3A protein
- Overactive PIK3A transmits signals for growth and division independently of other cells. This unchecked growth and division of the cell ultimately makes the cell cancerous
- The PIK3A Mutation Analysis Test is a genetic test that detects abnormalities in the PIK3A gene. It is used to diagnose cancer. It also aids in the treatment of cancers by guiding selection of therapeutic drugs, including disqualifying certain drugs from use
The molecular testing, in general, can be performed using a variety of methods. Some of these methods include:
- In situ hybridization technique, such as fluorescence in situ hybridization (FISH)
- Immunohistochemistry (IHC)
- Next-generation sequencing (NGS)
- Polymerase chain reaction (PCR)
- Comparative genomic hybridization (CGH)
- Karyotyping including spectral karyotyping
- mRNA analysis
- Tissue microarrays (TMAs)
- Southern blot test
- Northern blot test
- Western blot test
- Eastern blot test
The methodology used for the test may vary from one laboratory to another.
Note: Molecular testing has limitations due to the molecular method and genetic mutational abnormalities being tested. This can affect the results on a case-by-case basis. Consultation with your healthcare provider will help in determining the right test and right molecular method, based on individual circumstances.
What are the Clinical Indications for performing the PIK3CA Mutation Analysis Test?
Following are the clinical indications for performing the PIK3A Mutation Analysis Test:
- A firm, red nodule
- Bone pain
- Swelling of the face, arms or neck
- Headaches, dizziness or limbs that become weak or numb
- Lumps in the neck or collar bone region
- A flat sore with a scaly crust
- A new sore or raised area on an old scar or ulcer
- A rough, scaly patch on your lip that may evolve to an open sore
- A red sore or rough patch inside your mouth
- A red, raised patch or wart-like sore on or in the anus or on your genitals
In general, the molecular genetic testing is undertaken in the following situations:
• To assist (and in some cases, confirm) the initial diagnosis
• To distinguish other tumors/conditions that have similar histological features, when examined by a pathologist under the microscope
• To help in determining treatment options
• To confirm recurrence of the tumor: Tumor recurrence can either be at the original tumor site, or at a distant location (away from the initial site)
How is the Specimen Collected for PIK3CA Mutation Analysis Test?
Following is the specimen collection process for PIK3CA Mutation Analysis Test:
The specimen sample requirements may vary from lab to lab. Hence, it is important to contact the testing lab for exact specimen requirements, before initiating the testing process.
- Sample on which the test is performed may include:
- Fresh tumor tissue during biopsy
- Formalin-fixed paraffin-embedded solid tumor tissue (FFPE tumor tissue), often referred to as paraffin block of the tumor
- Unstained tissue slides
- Process of obtaining the sample: As outlined by the laboratory testing facility
- Preparation required: As outlined by the laboratory testing facility
- In some cases, a different source of specimen (such as peripheral blood, bone marrow biopsy specimen, or other body fluids) may be acceptable to the laboratory performing the test
- Occasionally, additional samples may be required to either repeat the test or to perform follow-up testing
- Depending on the location of testing, it may take up to 2 weeks’ turnaround time, to obtain the test results
- Many hospitals preserve the paraffin blocks for at least 7 years. In general, older paraffin blocks (over 5 years) may affect the detection of specific mutations, due to degradation of the tumor specimen over time
Cost of PIK3CA Mutation Analysis Test:
- The cost of the test procedure depends on a variety of factors, such as the type of your health insurance, annual deductibles, co-pay requirements, out-of-network and in-network of your healthcare providers and healthcare facilities
- In many cases, an estimate may be provided before the test is conducted. The final amount may depend upon the findings during the test procedure and post-operative care that is necessary (if any)
What is the Significance of the PIK3CA Mutation Analysis Test Result?
A mutation in the PIK3CA gene indicates a positive result for the PIK3CA Mutation Analysis Test. This may point to a diagnosis of any of the following:
- Epidermal nevus
- Squamous cell carcinoma
- Klippel-Trenaunay syndrome
- Lung cancer
- Megalencephaly-capillary malformation syndrome
- Ovarian cancer
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- PIK3CA mutation most notably occurs in a location of the chromosome called 3q26.32 i.e., the long arm (q) of chromosome 3 in position 26.32
- Many laboratories may not have the capability to perform this test. Only highly-specialized labs with advanced facilities and testing procedures may perform this test
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.
What are some Useful Resources for Additional Information?
The following DoveMed website link is a useful resource for additional information:
Please visit our Laboratory Procedures Center for more physician-approved health information:
References and Information Sources used for the Article:
https://ghr.nlm.nih.gov/primer/testing/genetictesting (accessed on 05/10/2017)
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5806a1.htm (accessed on 05/10/2017)
http://www.nature.com/gim/journal/v10/n5/full/gim200852a.html (accessed on 05/10/2017)
http://pediatrics.aappublications.org/content/106/6/1494 (accessed on 05/10/2017)
Lung Cancer Symptoms & Signs | CTCA. (n.d.). Retrieved from http://www.cancercenter.com/lung-cancer/symptoms/
PIK3CA gene - Genetics Home Reference. (n.d.). Retrieved from https://ghr.nlm.nih.gov/gene/PIK3CA#location
Symptoms and causes - Squamous cell carcinoma of the skin - Mayo Clinic. (2016, May 18). Retrieved from http://www.mayoclinic.org/diseases-conditions/squamous-cell-carcinoma/symptoms-causes/dxc-20204365
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