FISH testing is done by a pathologist. A pathologist is an expert who looks at and identifies cells.
To do a FISH test the pathologist needs some blood or tissue from your cancer
. This can be from a biopsy, blood sample or from when you had surgery to remove your cancer.
When is FISH test done?
FISH testing is done on breast cancer tissue removed
during biopsy
to see if the cells have extra copies of the HER2 gene. The more copies of the HER2 gene that are present, the more HER2 receptors the cells have. These HER2 receptors receive signals that stimulate the growth of breast cancer cells.
How is FISH test performed?
In FISH testing,
pieces of single-strand DNA (called DNA probes) are sent to find corresponding stretches of DNA from tumor cells sampled from the body
. The probes, marked with a fluorescent dye, attach to those corresponding cells—that process is called hybridization.
What is FISH used to diagnose?
FISH is applied to detect
genetic abnormalities
that include different characteristic gene fusions or the presence of an abnormal number of chromosomes in a cell or loss of a chromosomal region or a whole chromosome.
What is a positive FISH test?
FISH testing usually returns one of two results: positive or negative. Positive means
your breast cancer cells make too much HER2 and your doctor should treat you with drugs that target that protein
. Negative means the protein isn’t involved in the growth of your tumor.
How accurate is a FISH test?
FISH is
42-83% sensitive for detecting pTa and pT1 lesions and 92-100% sensitive for pT2-4 invasive lesions in patients with known bladder cancer
, while urine cytology yields sensitivities of 24-50% for pTa and pT1 lesions and 78-85% for pT2-4 invasive lesions.
How much does a FISH test cost?
FISH testing is directly billed to the patient, at a cost of
$794.00 per test
.
What does FISH mean in medical terms?
En Español.
Fluorescence in situ hybridization
(FISH) provides researchers with a way to visualize and map the genetic material in an individual’s cells, including specific genes or portions of genes. This may be used for understanding a variety of chromosomal abnormalities and other genetic mutations.
How do I read my FISH test results?
- A result of 0 is negative.
- A result of 1+ is also negative.
- A result of 2+ is considered equivocal (uncertain).
- A result of 3+ is positive.
Is it better to be HER2 negative?
In normal cells, HER2 helps control cell growth
. Cancer cells that are HER2 negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface.
How long does it take to get HER2 test results?
All invasive breast cancers are tested for HER2 levels. This is done in a hospital laboratory on a sample of breast cancer tissue removed during a biopsy or surgery. The results are usually available
between one and three weeks
later.
What is FISH test for bone marrow?
Fluorescent in situ hybridization (FISH) is
a technique which complements conventional cytogenetic banding analysis by allowing the evaluation of cells in interphase as well as metaphase
. This technique has been used to study air-dried peripheral blood and bone marrow aspirate smears.
What is FISH testing in genetics?
Fluorescence in situ hybridization (FISH) is
a laboratory technique for detecting and locating a specific DNA sequence on a chromosome
. The technique relies on exposing chromosomes to a small DNA sequence called a probe that has a fluorescent molecule attached to it.
Is FISH a cytogenetic test?
Fluorescence In Situ Hybridization (FISH) is
a powerful molecular/cytogenetic technique
that utilizes a fluorescent-labeled DNA probe to ascertain the presence or absence of a particular segment of DNA.
How do you test for HER2?
Most HER2 testing involves
taking a sample of tumor tissue in a procedure called a biopsy
. There are three main types of biopsy procedures: Fine needle aspiration biopsy, which uses a very thin needle to remove a sample of breast cells or fluid. Core needle biopsy, which uses a larger needle to remove a sample.
Can a FISH test be wrong?
Accuracy and limitations.
Prenatal interphase FISH testing is highly accurate, with reported false-positive and -negative rates usually less than 1%
. The main problem, however, is that not all specimens are informative. Uninformative rates will vary among laboratories, but rates of 3% to 10% are considered typical.
