What does HER2 FISH negative mean?
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.
What is HER2 in situ hybridization?
Fluorescence in situ hybridization (FISH) is a test that “maps” the genetic material in a person’s cells. This test can be used to visualize specific genes or portions of genes. FISH testing is done on breast cancer tissue removed during biopsy to see if the cells have extra copies of the HER2 gene.
How do I read my fish test results?
How your doctor interprets this test is as follows:
- 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.
What is the difference between FISH and CISH?
FISH probes are generally labelled with a variety of different fluorescent tags and can only be detected under a fluorescence microscope, whereas CISH probes are labelled with biotin or digoxigenin and can be detected using a bright-field microscope after other treatment steps have been applied.
What is a CISH reaction?
Chromogenic in-situ hybridization (CISH) is a relatively new method for determination of gene amplification using a peroxidase-based chromogenic reaction, which can be viewed using a conventional bright field microscope. Like FISH, CISH determines the actual degree of HER2 gene amplification.
What does it mean when HER2 is equivocal?
If the IHC result is 2+, the HER2 status of the tumor is not clear and is called “equivocal.” This means that the HER2 status needs to be tested with FISH to clarify the result.
Is HER2-negative better than positive?
HER2-positive cancer tends to be poorer in terms of prognosis than HER2-negative cancer because: It grows faster. It is more likely to spread to the lymph nodes fast. It is at least two times more likely to return than HER2-negative tumors.
Is the FISH test accurate?
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.