The clinical implications of telomerase activity in upper tract urothelial cancer and washings.

摘要

OBJECTIVE: To measure telomerase activity in upper tract urothelial carcinomas (as renal pelvic tumours comprise nearly half of all kidney tumours in Taiwan, a much higher percentage than in other countries) and to determine whether telomerase activity could be used as an additional diagnostic marker in exfoliated cancer cells present in upper tract urothelial washing fluids, thus providing earlier diagnosis and treatment. Materials and methods Telomerase activity was assessed using the telomeric repeat amplification protocol assay in tissue samples from 31 upper tract urothelial carcinomas (from 29 patients). The feasibility of identifying cancer using telomerase activity in exfoliated cancer cells in 17 upper tract urothelial washing samples was also investigated. RESULTS: Telomerase activity was found in 30 (97%) of the 31 upper tract urothelial cancer tissue samples; telomerase activity was detectable in 95% of superficial cancers and in all 11 invasive tumours. The sensitivity of measuring telomerase activity was 100% for grade 1, 93% for grade 2 and 100% for grade 3 tumours. In contrast, telomerase activity was detected in only two (8%) of 26 normal adjacent tissue samples. When the telomerase activity of urothelial washing fluid was compared with that in the corresponding tumours, there was compatible telomerase activity in 15 of the 17 samples. Telomerase activity was more sensitive than voided urine cytology (15%) and washing fluid cytology (53%). In addition, the telomerase activity was high in metastatic lesions. CONCLUSION: Telomerase activity is present in most upper tract urothelial cancer tissues and may be present at an early stage of carcinogenesis. Telomerase activity can be detected in exfoliated cells in urothelial washing fluids in a high proportion of patients with upper tract urothelial cancer. These results suggest that measuring telomerase activity in the exfoliated cancer cells obtained from urothelial washing could be a potentially useful addition to the conventional diagnostic tools used to identify patients with upper tract urothelial carcinoma.