A Comparative Study of Telomerase Activity and Cytologic Diagnosis in Malignant Ascites

OBJECTIVE: To evaluate telomerase activity as an adjunct in the cytologic diagnosis of malignant ascites. STUDY DESIGN: Malignant ascites collected from 19 gastrointestinal or liver cancer patients with clinical or pathologic evidence of peritoneal metastasis were tested for routine cytology with a liquid-based preparation, and telomerase activity was measured by telomere-repeat amplification protocol (TRAP) and real-time quantitative TRAP (RTQ-TRAP) assays. For comparison, controls from peritoneal washings from 8 early gastric cancer patients were used. RESULTS: Cytological examination detected cancer cells in 8 patients (42%), and 3 cases (16%) were diagnosed as "atypia." With TRAP and RTQ-TRAP assays 16 (84%) and 15 (78%) cases, respectively, were positive for telomerase activity. The sensitivity of telome- rase activity by TRAP, RTQ-TRAP assays, and cytology was 84%, 78%, and 58%, respectively. All cases with "atypia" by cytological examination were positive for both TRAP and RTQ-PCR assays. In all negative controls, cytology, TRAP and RTQ-TRAP assays were negative. CONCLUSION: Based on our findings telomerase activity is a more sensitive method than ascitic fluid cytology and therefore can be considered as a useful diagnostic adjunct to current standard diagnostic methods. However, further large cohort studies with clinical correlation are needed to confirm our findings.