Mar 10, 2011The FISH assay and urinary cytology both demonstrate high rates of false positivity and are useful mainly for their negative predictive ability IntroductionMaterials and methodsResultsDiscussion
Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens.
Clinical significance
In breast cancer patients, for example, a FISH test on breast cancer tissue removed during a biopsy can show whether the cells have extra copies of the HER2 gene.
Cells with extra copies of the gene have more HER2 receptors, which receive signals that stimulate the growth of breast cancer cells.
So patients with extra copies of the gene are more li.
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Diagnosis
Because a FISH test can detect genetic abnormalities associated with cancer, it's useful for diagnosing some types of the disease.
When the type of cancer has previously been diagnosed, a FISH test also may provide additional information to help predict a patient's outcome and whether he or she is likely to respond to chemotherapy drugs.
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Example
During a FISH test using a sample of the patient's tissue, special colored dyes are attached to specific parts of certain chromosomes in order to visualize and count them under a fluorescent microscope and to detect cancer-promoting abnormalities.
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How does fish detect neoplasia?
Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens.
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How is fish used in cytogenetic research?
FISH has become a central cytogenetic tool.
Probe fragments can be derived from various sources, by recombinant methods or by PCR.
Today, accurately mapped bacterial artificial chromosomes (BAC) are the most frequently used probe type.
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Summary
Fluorescence in situ hybridization (FISH) is a test that \\"maps\\" the genetic material in human cells, including specific genes or portions of genes.
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Use
Because FISH testing is expensive and not widely available, it's not as commonly used as another breast cancer test: ImmunoHistoChemistry (IHC).
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What is fish urine cytology?
FISH:
- This test is called Fluorescence in situ Hybridization
- also popularly known as Fish Urine Cytology
This test is done for diagnosing or monitoring urothelial cancer.
The pathologist diagnoses the samples of the urine and checks for the abnormal signs or warnings that indicate carcinoma.
Urine cytology results can take 1-2 or even more days.
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What is the difference between cytology and FISH analysis?
FISH analysis yielded a high sensitivity for detecting new cases of urothelial carcinoma, as well as recurrences.
FISH detected 95% of cases with high-grade carcinoma, while cytology detected 41% of such cases.
FISH yielded an overall specificity of 65%, compared to 93% with cytology.
