Loss of P16 (9p21) and 3, 7, 17 aneuploidy
The loss of tumor suppressor gene P16 / CDKN2A / INK4A / MTS1 (9p21) is a prognostic factor associated with bladder cancer recurrence. Together with the identification and quantification of chromosomes 3, 7 and 17 aneuploidy in urine samples from patients with hematuria suspected of having bladder cancer, is intended for use, in conjunction with and not in lieu of current standard diagnostic procedures, as an aid for initial diagnosis of bladder carcinoma in patients with hematuria and subsequent monitoring for tumor recurrence in patients previously diagnosed with bladder cancer.
The UroVysion® Bladder Cancer test (UroVysion Kit) is FDA approved and designed to detect aneuploidy for chromosomes 3, 7, 17, and loss of the 9p21 locus via fluorescence in situ hybridization (FISH). This test detects chromosome abnormalities associated with the development and progression of bladder cancer and, used along with cystoscopy, achieves the best balance of sensitivity (97%) and specificity (96%). The results of this analysis are not altered in patients treated with BCG (Bacillus Calmette-Guerin), while cystoscopy and cytology can give misleading results in these patients, so the genetic profile allows more accurate monitoring of these patients. While 45% of cytology results are ambiguous, genetic studies are interpretable in all the cases, allowing detection of recurrence up to 6 months before other current diagnostic methods. Early detection in high-grade disease is critical for increasing survival.
