Detection of telomerase activity in breast masses by fine-needle aspiration

Telomerase is an RNA-dependent DNA polymerase that compensates for the telomere shortening that occurs in its absence. Reactivation of telomerase is thought to be an important step in cellular immortalization, and recent studies have indicated that telomerase activity is often detected in primary human malignancies. The clinical implications of telomerase activity in human tumors are currently under investigation.

Eighty-nine samples (46 FNAs and 43 gross tissue biopsies) from 44 patients with breast masses were analyzed prospectively for the presence of telomerase activity by a modification of the telomere repeat amplification protocol (TRAP). All samples were obtained directly from the excised mass at the time of specimen removal in the operating room.

Telomerase activity was detected in 17 of 19 (90%) FNA samples and 15 of 18 (83%) invasive breast cancer tissue biopsies. Telomerase was also detected in 9 of 16 (56%) FNAs and 8 of 15 (53%) tissue biopsies from 16 fibroadenomas. Other benign proliferative lesions (n = 5) did not have detectable telomerase activity in either FNA or tissue specimens. FNA-TRAP results correlated with the gross tissue specimen TRAP results in 95% of all cases.

The FNA-TRAP assay for telomerase detection is a highly sensitive and accurate method for the detection of telomerase activity in breast masses. Future application of these techniques should facilitate evaluation of telomerase as a tumor marker in the clinical management of breast and other solid malignancies.