A comparative study of telomerase activity and cytologic diagnosis in malignant ascites

To evaluate telomerase activity as an adjunct in the cytologic diagnosis of malignant ascites.

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.

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 telomerase 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.

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.