Telomerase activity in needle biopsies from prostate cancer and benign prostates

Background Telomerase activation is thought to be essential for the immorta lity of cancer cells. It may be a prognostic factor in small volume well di fferentiated prostate cancers and hence a guide for the aggressiveness of t he approach. The length of the chromosome tips (telomeres) are maintained b y a specific enzyme (telomerase) independently of the normal cell division cycle. Although telomerase is not expressed in most normal human tissues, i t is expressed in most human tumours. For the detection of telomerase in sm all prostate needle biopsy samples a recently developed telomeric repeat am plification protocol (TRAP) assay was used. The aim of the present study wa s: to measure telomerase activity in human prostate samples, and to evaluat e the applicability of this assay on specimens from a prostate biopsy. Materials and methods From 36 patients referred for lower urinary tract sym ptoms (LUTS) or suspicion of having prostate cancer a total of 288 prostate biopsy samples were obtained (8 in each patient). When the digital rectal examination was abnormal and/or when the PSA level was elevated in L.U.T.S. , or asymptomatic patients' tissue samples were obtained by transrectal ult rasound (TRUS) guided biopsies. Samples were tested for telomerase activity by a modified TRAP and forwarded for histology. Results In 19 out of 36 patients prostate cancer was diagnosed on histology . In 11 of these 19 tumours substantial telomerase activity was detected, w hereas only very low telomerase activity existed in 2 of 17 samples from be nign prostatic hypertrophy (BPH) patients. In this small series the relativ e telomerase activity in prostate cancer correlated with histopathological grade. Conclusions Our results show the applicability of a TRAP assay to measure t elomerase activity in small needle biopsied prostate samples. In poorly dif ferentiated and metastatic cancer we observed that levels of telomerase act ivity were high. To establish accuracy and to distinguish the 'relative goo d from the ugly' further study is needed.