Letters to the Editor Correspondence re: Seki et al., Diagnosis of pancreatic adenocarcinoma by detection of human telomerase reverse transcriptase messenger RNA in pancreatic juice with sample qualification. Clin. Cancer Res., 7: 1976 –1981, 2001. We read with interest the article by Seki et al. (1) and agree with the authors that hTERT 1 has a potential role in the diag- nosis of cancer. However, we were surprised that the authors did not report the mRNA copy numbers for hTERT despite stating -actin mRNA levels in the samples. It is recognized that lymphocytes contain low levels of telomerase and its catalytic subunit hTERT (2). Therefore, quantification of hTERT mRNA can lead to the identification of cut-off values for the diagnosis of cancer. Using the RNA assay, we have previously reported telom- erase activity in 74% of human breast cancers and in none of the benign breast tissue specimens (3). We have recently measured hTERT mRNA and -actin mRNA levels in 80 breast speci- mens (40 carcinomas and 40 benign breast tissue samples) using quantitative reverse transcription-PCR. Our data show signifi- cantly higher levels of hTERT mRNA in tumor than in benign breast tissue (P  0.0001). Using a cut-off value of 5000 mRNA copies per g of RNA, we can achieve a sensitivity of 93% and a specificity of 100% in the diagnosis of breast cancer. This data will be presented during the 24th San Antonio Breast Cancer Sympo- sium (4). In agreement with Seki and colleagues, we have found -actin mRNA levels helpful in assessing RNA quality and quantity in the samples to exclude those unsuitable for hTERT analysis. We believe that chronic pancreatitis samples are likely to contain significantly lower levels of hTERT than those of pancreatic carcinoma and that the use of CD25 positivity to exclude hTERT positive samples can reduce the test sensitivity because most tumors are infiltrated by lymphocytes. Kirsten S. Hindle Katherine Kirkpatrick Kefah Mokbel 2 St. George’s Breast Centre Blackshaw Road London SW17 OQT, United Kingdom References 1. Seki, K., Suda, T., Aoyagi, Y., Sugawara, S., Natsui, M., Motoyama, H., Shirai, Y., Sekine, T., Kawai, H., Mita, Y., Waguri, N., Kuroiwa, T., Igarashi, M., and Asakura, H. Diagnosis of pancreatic adenocarcinoma by detection of human telomerase reverse transcriptase messenger RNA in pancreatic juice with sample qualification. Clin. Cancer Res., 7: 1976 –1981, 2001. 2. Mokbel, K. The role of telomerase in breast cancer. Eur. J. Surg. Oncol., 26: 509 –514, 2000. 3. Mokbel, K., Parris, C. N., Ghilchik, M., Williams, G., and Newbold, R. F. The association between telomerase, histopathological parameters, and KI-67 expression in breast cancer. Am. J. Surg., 178: 69 –72, 1999. 4. Kirkpatrick, K., Ogunkolade, W., Bustin, S., Jenkins, P., Ghilchik, M., and Mokbel, K. hTERT expression in human breast cancer. The 24th Annual San Antonio Breast Cancer Symposium, in press, 2001. Received 10/2/01; accepted 11/15/01. 1 The abbreviation used is: hTERT, human telomerase reverse transcriptase. 2 To whom requests for reprints should be addressed, at: St. George’s Breast Centre, Blackshaw Road, London SW17 OQT, United Kingdom. 628 Vol. 8, 628, February 2002 Clinical Cancer Research Research. on January 20, 2022. © 2002 American Association for Cancer clincancerres.aacrjournals.org Downloaded from