Analysis of hTERT mRNA expression in biliary tract and pancreatic cancer

Telomerase, an enzyme that prevents the loss of telomere regions consisting of TTAGGG repeats, which maintain the stability of cells, is considered to be involved in cell immortality and cancer growth. Recent genetic analysis has shown that the mRNA for the catalytic subunit of human telomerase reverse transcriptase (hTERT) is expressed in many cancer tissues.

In this study, we measured hTERT mRNA levels in bile samples from patients with pancreatobiliary disease, and we combined the hTERT mRNA analysis with conventional cytology to achieve an accurate preoperative diagnosis. Bile samples were obtained from 19 patients with biliary tract cancer, 6 with gallbladder cancer, 10 with pancreatic cancer, 1 with gastric cancer, and 10 with benign disease. These samples were examined cytologically, and analyzed for hTERT mRNA levels.

The Combination of cytological examination and hTERT mRNA analysis achieved a positive rate of 78.9% in diagnosing biliary tract cancer, significantly improving the diagnostic accuracy over that for either method alone (P = 0.01). The diagnostic sensitivity for malignant disease was 66.6%, also significantly improving the diagnostic accuracy compared with either method alone (P = 0.001).

The combination of cytological examination and hTERT mRNA analysis appeared useful for the preoperative diagnosis of malignant biliary tract diseases, but was not superior to diagnostic imaging studies, and therefore remains an adjunct to cytological examination. Further studies should lead to improvements in the combination's diagnostic capabilities.