The association between telomerase, histopathological parameters, and KI-67 expression in breast cancer

BACKGROUND: Telomerase is a ribonucleoprotein enzyme that appears to play a n important role in carcinogenesis. Telomerase reactivation seems to be ass ociated with immortalization and malignancy, METHODS: Using a polymerase chain reaction (PCR)-based assay known as the T RAP (telomeric repeat and amplification protocol) assay, we examined telome rase activity in 60 breast specimens prospectively collected from 39 patien ts undergoing elective breast surgery in our center. The specimens included adjacent noncancerous breast (n = 21), benign breast disease (n = 5), and infiltrating carcinoma (n = 34), Ki-67 expression was determined in 32 inva sive breast cancer specimens using immunohistochemistry techniques. The his topathological features were determined by light microscopy by an experienc ed breast pathologist, RESULTS: Telomerase activity was detected in 24 (71%) of 34 infiltrating ca rcinomas. None of the adjacent noncancerous specimens nor the benign breast lesions expressed telomerase activity. Telomerase reactivation was signifi cantly associated with nodal metastasis and Ki-67 expression. There was no significant association between telomerase activity and menopausal status, tumor grade, or tumor size. CONCLUSIONS: Telomerase reactivation is associated with the acquisition of malignancy in the human breast. Telomerase activity is significantly associ ated with nodal metastasis and cellular proliferation as measured by Ki-67 expression in human breast cancer. Am J Surg. 1999;178:69-72, (C) 1999 by E xcerpta Medica, Inc.