Significant cell populations with chromosomal gains or homozygous 9p21 deletion indicate that the patient has a genitourinary malignancy, which is most frequently bladder cancer, or (much less likely) a metastatic involvement of the genitourinary tract. However, the patient may have another genitourinary malignancy (eg, renal pelvic or ureteral transitional cell carcinoma, prostatic carcinoma with urethral invasion, renal cell carcinoma, or metastatic cancer involving the genitourinary tract).
This assay is intended for detecting tumor and does not provide information on tumor stage.
Biopsy may help clarify the diagnosis and tumor stage.
Cystoscopy and urine cytology have been the primary methods for detecting urothelial carcinoma (UC). Unfortunately, urine cytology has relatively poor sensitivity for the detection of recurrent UC. This is problematic because patients who have undetected recurrent tumors may have tumor progression that places them at increased risk of developing metastatic UC.
The UroVysion assay is a fluorescence in situ hybridization (FISH) assay for the detection of recurrent UC. The UroVysion probe set contains probes to the centromeres of chromosomes 3, 7, and 17, and a locus-specific probe to the 9p21 band (site of the P16 tumor suppressor gene). The UroVysion assay detects cells with chromosomal abnormalities that are consistent with a diagnosis of UC. Studies have shown that the assay has higher sensitivity than urine cytology but similar specificity for the detection of recurrent UC. The UroVysion assay also demonstrates higher specificity than the BTA-stat assay for recurrent UC.
Lower Tract Samples:
Abnormal: any specimen satisfying 1 of the following criteria:
-Four or more cells with gains of 2 or more chromosomes
-Ten or more cells with a gain of a single chromosome or 10 or more cells with tetrasomic signal patterns (ie, 4 copies for each of the 4 probes)
-Homozygous deletion of the 9p21 locus in 20% or more of the cells analyzed
For cases that are abnormal, the percentage of abnormal cells and type of chromosomal abnormality (ie, polysomy, trisomy, tetrasomy, or homozygous 9p21 deletion) are indicated in the test report.
-Fewer than 4 cells with gains of 2 or more chromosomes
-Fewer than 10 cells with gain of a single chromosome or tetrasomy
-Less than 20% of cells with homozygous 9p21 deletion
Upper Tract Samples:
Abnormal: any upper tract specimen satisfying 1 of the following criteria:
-Four or more hypertetrasomy cells with at least 5 copies of 2 or more chromosomes
-Ten or more cells with a gain of a single chromosome or 10% or more cells with tetrasomic or near-tetrasomic signal patterns (ie, 4 copies for each of the 4 probes)
-Fewer than 4 cells with hypertetrasomy with at least 5 copies of 2 or more chromosomes
-Fewer than 10% of cells with tetrasomy