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Your question confused me until I caught on...
It is FISH testing, not FSH testing (FSH is follicle stimulating hormone, which is secreted to cause ovulation every month) so I thought your question might have had to do with fertility testing in someone after chemo.
Now that someone else has replied, it seems your question has to do with FISH testing, so I just copied and pasted two bits of info from this website itself.
From the section on testing on THIS WEBSITE--put the word test into the search to find an illustrating picture as well as more on other tests:
Fluorescence in situ hybridization (FISH) is a type of hybridization in which a DNA "probe"* is labeled with fluorescent molecules so that it can be seen with a microscope. The word "in situ" means that the hybridization occurs "in place", in this case, within the nucleus of specimen cells that have been fixed to a microscope slide.
To conduct a FISH analysis, one warms fixed cells mounted on a microscope slide to unwind their chromosomal DNA and allow access of the DNA probe. After adding the probe, the specimen cells are then cooled to allow the DNA probe to hybridize with its complementary target DNA. Once hybridized, the fluorescent molecules*on the probe will show precisely where their target DNA lies along a chromosome. Depending upon the design of the probe DNA, one can detect many types of genetic changes.
*
FISH is the most commonly used test to detect HER2 DNA amplification. It is highly sensitive and specific and is suitable for use in both archived and fresh specimens. Amplification >2 is associated with a high proportion of responses of breast cancer to trastuzumab. Its disadvantages relate principally to laboratory time and cost issues, and it is important to ensure that infiltrating rather than in situ tumor is evaluated. Occasionally, FISH may be positive in breast tumor tissue that scores 0 by IHC.2 Outcomes from using trastuzumab treatment for such patients are not known.
There was an 82% concordance between the IHC clinical trials assay (CTA) and FISH in the patients entered into the initial trastuzumab clinical trials H06489, H06499, and H06509. 7 No improvement in chemotherapy response rates or survival from the addition of trastuzumab occurred in FISH-negative patients entered on the initial trials of cyclophosphamide plus doxorubicin (CA) or of paclitaxel plus or minus trastuzumab. In the trastuzumab-alone studies,5,9 no responses occurred in the FISH-negative group, including 17 patients who demonstrated 3+ CTA IHC scores. Thus, FISH appears to be a more precise test than IHC for determining the likelihood of a patient responding to trastuzumab.
A policy for HER testing now followed in many laboratories, including in our own institution, is for IHC testing to be performed as the standard routine test for HER2 overexpression in all newly diagnosed patients with invasive breast cancer. Test results that are reported as 3+ are accepted as being positive, and those reported as 0 or 1+ are* considered as negative. FISH is performed routinely when IHC results are 2+ or when the 0 or 1+ IHC results are questioned from a clinical point of view, such as in a patient with a possible HER2-positive phenotype (ie, aggressive clinical course) or in old archived tissue. Most new cooperative group breast cancer protocols that study trastuzumab in breast cancer will accept patients who have either a 3+ IHC result or a positive FISH test. Some protocols require performance of both tests. It seems likely that FISH will replace IHC for assessment of tumor HER2 when automated procedures become widely available
Hope this helps!
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what does ratio in FSH test mean?
Hybrid Mode
