Clinical usefulness of telomerase for the detection of colon cancer in ulcerative colitis patients
Article first published online: 1 JUN 2005
Journal of Gastroenterology and Hepatology
Volume 20, Issue 10, pages 1578–1583, October 2005
How to Cite
MYUNG, S.-J., YANG, S.-K., CHANG, H.-S., BYEON, J.-S., KIM, K.-J., HONG, S. S., JEONG, J.-Y., LEE, S.-M., HONG, W.-S., KIM, J.-H. and MIN, Y. I. (2005), Clinical usefulness of telomerase for the detection of colon cancer in ulcerative colitis patients. Journal of Gastroenterology and Hepatology, 20: 1578–1583. doi: 10.1111/j.1440-1746.2005.03877.x
- Issue published online: 31 AUG 2005
- Article first published online: 1 JUN 2005
- Accepted for publication 9 November 2004.
- colorectal cancer;
- telomerase reverse transcriptase;
- ulcerative colitis
Background and Aim: Colorectal carcinoma (CRC) is a complication of ulcerative colitis (UC). Although stool occult blood and colonoscopy are used to detect CRC in UC, these methods have drawbacks, in that bleeding is associated with UC and the underlying mucosa is irregular, making it difficult to detect dysplasia. Telomerase and its catalytic subunit, telomerase reverse transcriptase (hTERT), are specifically expressed in cancers, making them candidate markers for the early detection of cancer. We previously reported that assays of telomerase in pancreatic juice may be useful for the early detection of pancreatic cancer. The aims of our study were to determine whether assays for telomerase and TERT may be useful in the diagnosis of CRC developed in UC patients.
Methods: Luminal washings and biopsies were collected during colonoscopy in 66 patients; 34 with CRC, 21 with UC, and 11 controls. Telomerase activity was detected by telomeric repeat amplification protocol (TRAP) and hTERT mRNA was assayed by reverse transcription–polymerase chain reaction (RT-PCR).
Results: Telomerase activity was detected in biopsies from 33 of 34 (97%) CRC patients, 14 of 21 (67%) UC patients, and three of 11 (27%) normal controls. Expression of hTERT mRNA was observed in biopsies from 32 of 34 (94%) CRC patients, 12 of 21 (57%) UC patients, and five of 11 (45%) controls. In analyses of washing fluid, 21 of 34 (62%) of CRC patients were positive for telomerase, but all UC patients and controls were negative. The sensitivity of telomerase for CRC was 97% in tissues and 62% in washing fluid. The specificity of telomerase in washing fluid was 100%, whereas the specificity of telomerase or hTERT mRNA in tissues was 47% each.
Conclusions: For the detection of CRC arising in UC, telomerase and hTERT in colonic tissue showed high sensitivity, and telomerase in colonoscopic luminal washings revealed a high specificity. These might be candidate markers in clinical decision making for the diagnosis of CRC from UC.
© 2005 Blackwell Publishing Asia Pty Ltd