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| SERVICES - VYSIS UROVYSIONTM TESTING |
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Most solid tumors are characterized by chromosomal abnormalities. Fluorescence in situ hybridization (FISH) is a technique that utilizes fluorescently-labeled DNA probes to detect chromosomal abnormalities. FISH has applications in many areas of medicine and has proven to be very accurate for detecting bladder carcinoma using the Vysis UroVysion test.
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Normal cell without chromosomal abnormalities: Two signals are present for chromosomes 3 (red), 7 (green), and 17 (aqua), and two copies of the locus for p16 (gold). |
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Bladder Cancer cell with chromosomal abnormalities including three copies of chromosome 7 (green) and 17 (aqua) and absent p16 locus (gold). |
There are two types of FISH probes, centromeric and locus specific. Centromeric probes are useful in determining how many copies of a chromosome are present in a cell. Normal cells have two copies of each chromosome. Bladder cancer cells frequently have more than two copies of the various chromosomes. Locus specific probes identify gene-related areas on individual chromosomes.
UroVysion evaluates the number of copies of chromosomes 3, 7 and 17 as well as the locus for the p16 tumor suppressor gene in transitional cells. Different colors are used to probe the different chromosomes and the p16 locus in single cells.
FISH for Urothelial Cancer
FISH offers the high specificity of urine cytology, but is significantly more sensitive than cytology for the detection of Urothelial Carcinoma (UC). Recently conducted FDA trials, to evaluate the Vysis UroVysion, found that FISH was more sensitive than cytology or BTA-stat for UC detection, and more specific than BTA-stat for UC detection.
Vysis UroVysion in combination with cystoscopy offers the best available combination of sensitivity and specificity - 97% sensitivity and 96% specificity.
For physicians, the Vysis UroVysion test serves to appropriately heighten suspicion and increase surveillance efforts in selected patients where cancer is not detected by visual methods. For the patient, this means that the chance of catching the cancer earlier is greatly improved.
Method
FISH for Urothelial Cancer can be performed on any type of urine specimen including voided and catheterized specimens. The FISH assay is performed by isolating cells from the urine by centrifugation, placing the cells on a slide, doing the FISH hybridization and then interpreting the slide with a fluorescence microscope. The slide is scanned primarily, but not exclusively, for cells that have abnormal cytologic features when viewed with a nuclear counterstain. Scanning increases the sensitivity of the assay because the technologist scans the entire slide and all cells on the slide instead of evaluating only a certain number of consecutive cells.
Vysis UroVysion
- Superior noninvasive method for monitoring tumor recurrence in patients with bladder cancer.
- Valuable aid for initial diagnosis of bladder carcinoma in patients with hematuria.
- Combines genomic DNA probe analysis with direct morphologic observation.
- Greater sensitivity with fewer false negatives.
- Results are either positive or negative, there are no atypical, suspicious diagnoses.
- FDA cleared.
- Not affected by BCG immunotherapy.
Specimen Collection:
- Collection kits are supplied by ClearPath Diagnostics.
- Pour fresh urine in fixative container(s) within 15 minutes.
- Fill first fixative container to the top. Place additional urine in a second container.
- Refrigerate immediately and arrange for delivery. Must be received within 72 hours.
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