Markers in bladder cancer: Their role continues to evolve

October 15, 2005

Increasingly, physicians look to the use of biomarkers as precursors of various cancers, including bladder cancer, and rely on them to some degree to guide diagnosis and treatment decisions. However, the science of biomarkers as diagnostics is still in its infancy, and their clinical use has some limitations. In this interview, Michael A. O'Donnell, MD, discusses developments in marker tests and how they compare with cystoscopy and cytology in the diagnosis of bladder cancer.

Increasingly, physicians look to the use of biomarkers as precursors of various cancers, including bladder cancer, and rely on them to some degree to guide diagnosis and treatment decisions. However, the science of biomarkers as diagnostics is still in its infancy, and their clinical use has some limitations. In this interview, Michael A. O'Donnell, MD, discusses developments in marker tests and how they compare with cystoscopy and cytology in the diagnosis of bladder cancer. Dr. O'Donnell is professor and director of urologic oncology at the University of Iowa, Iowa City. He was interviewed by UT Editorial Consultant Robert C. Flanigan, MD, professor and chairman, department of urology, Loyola University, Maywood, IL.

Q. Please start by telling us what you think is the role of markers in bladder cancer. How are you using bladder cancer markers in your practice at this time?

Q. Are you using all three tests, or has one replaced the others?

I'm not alone in this. I have physicians calling from across the country wondering what they should do with a positive FISH test.

Q. Has your practice been to take those patients to a random bladder biopsy on the basis of a positive FISH test?

A. I use a positive FISH test as sort of an "orange alert" for the bladder, which means cancer may be present and should be sought. Then I go back and do random biopsies, retrogrades, washings for cytology on the upper tracts, and prostate urethral biopsies. If those are all negative, I'll follow those patients prospectively with cystoscopy, cytology, and continued FISH tests, albeit on a more frequent 3-month basis.

Q. Even in that circumstance, where you have the so-called gold standard of a random bladder biopsy, you're not finding the same degree of specificity?

A. Absolutely not. Our follow-up using FISH for most of these patients is just a year and a half, but if we believe the previous studies, that 90% of all anticipatory FISH tests will reveal themselves within 1 year, we should have found everything by now. That's certainly not the case.

FISH has been pretty good in terms of negative prediction, but I've had a couple of cases of very small tumors and low-grade and even very small-volume carcinoma in situ that have been missed by the FISH test.