Abstract: Objective To examine possible associations between telomerase activity and clinicopathological features of ovarian epithelial cancer patients and examine the ability of different cisplatin-based chemotherapy protocols to inhibit telomerase activity. Methods Tumor reduction surgery combined with lymph node dissection were performed in 43 patients with primary ovarian epithelial cancer.Cancer tissue from all patients was analyzed by TRAP-PCR-augmentation to detect telomerase activity，RT-PCR to measure hTERT gene expression， and immunohistochemistry to measure hTERT protein expression. Patients were divided into three treatment groups，each of which received an average of 6.5 cycles（range，6-8）of a different cisplatin-based chemotherapy：CC，cisplatin+cyclophosphamide；CP，cisplatin+paclitaxel；CCD，cisplatin+cyclophosphamide+doxorubicin.All patients were subjected to clinical and imaging exams；second-look laparotomy was also performed in patients with normal CA125 levels and no residual tumor（13 CC patients，11 CP patients，and 6 CCD patients）.Tissues around the original lesions were checked by biopsy.All patients were followed up to calculate 5-year survival rate. Results Telomerase activity did not correlate with pathology type，grade or FIGO stage in the entire group of patients（P<0.05）.All three chemotherapy protocols significantly reduced telomerase activity and hTERT protein expression （P<0.05）.The 5-year survival rate was similar for all three protocols（P>0.05）. Conclusions Cisplatin-based chemotherapy significantly suppresses telomerase activity.CP chemotherapy can decrease telomerase activity more than CC or CCD therapy， but this does not translate into a higher 5-year survival rate， perhaps because of drug resistance.

Key words:  Ovarian neoplasms, Telomerase, hTERT, Chemotherapy, Cisplatin