Telomerase Activity Potential Marker for Bladder Cancer

NEW ORLEANS--The enzyme telomerase is detectable in the majority ofbladder washings from patients with bladder cancer, making it a reliablemarker for cancer, according to several reports presented at the AmericanUrolog-ical Association (AUA) annual meeting.

Telomerase is thought to be responsible for maintaining telomere intumors, allowing cancer cells to avoid programmed cell death. It has beenfound in up to 90% of all cancers tested.

The Society for Urologic Oncology's Clinical Research Award was presentedto Drs. Elizabeth Kavaler and Brian Liu, of Mt. Sinai Medical Center, NewYork, together with other Mt. Sinai investigators led by Dr. Michael J.Droller, professor and chairman of urology, for their research in thisarea.

The investigators used PCR-based telomeric repeat amplification (TRAP)to detect telomerase in voided samples from 57 patients with bladder cancer.They found telomerase activity to be very useful in diagnosing low-gradebladder cancer, much more so than cytology readings from the same samples.

Of the 57 samples, 52 (91%) tested positive for telomerase. This included100% of the grade 1 tumors, 92% of the grade 2 tumors, and 83% of the grade3 tumors. Two patients with carcinoma in situ were also positive for telomerase,Dr. Kavaler reported.

In contrast, telomerase was not found in samples from 23 of 30 patientswith other urinary disorders. Furthermore, it was present in 21 of 41 bladdercancer samples for which cytology had yielded a false-negative readingfor tumor. Cytology diagnosed none of the grade 1 tumors, 39% of the grade2 tumors, and 78% of the grade 3 tumors.

Other Reports

German investigators evaluated the test in 75 tissue samples, 40 bladderwashings, and 36 urine samples taken from patients with urothelial carcinomaof the bladder. Eight tissue samples were taken from normal urothelium.

The researchers detected telomerase activity in 96% of the tissue samplesfrom patients with histologically confirmed cancer. No normal tissue samplesshowed telomerase activity.

Telomerase activity was also found in 73% of the bladder washings fromcancer patients, and there were no false-positive results, Dr. Marcus Muller,of Benjamin Franklin University Hospital, Berlin, reported.

A report from Seoul, Korea, found telomerase activity in tissue andbladder washings in 96% of cases of bladder transitional cell carcinoma.Cytologic analysis diagnosed 70% of the cancers and missed all but onecase of grade 1 disease, Dr. Dong-hyeon Lee, of Yonsei University, reported.

In a study from Madigan Army Center, Tacoma, Washington, all 22 solidtransitional cell bladder carcinomas exhibited telomerase activity, whileeight of 10 benign urothelial specimens did not. Telomerase activity wasidentified in 80% of bladder washings from patients with histologicallyconfirmed cancer, including 75% of those with in situ tumors.

Telomerase activity was not detected in 66% of control subjects withnormal cystoscopy. About 30% of the false-positive cases were found tohave urothelial atypia, Dr. Raymond S. Lance reported.