Telomerase activity as a marker of breast carcinoma in fine-needle aspirated samples

BACKGROUND. Telomerase activity in breast fine-needle aspiration (FNA) samp les may have diagnostic utility. The purpose of this study was to compare i n FNA samples of breast tumor the diagnostic accuracy as correlated with hi stologic final diagnosis. METHODS. Fine-needle aspiration samples were obtained from 617 patients wit h palpable breast tumors. Slide preparation and cytology were performed acc ording to a uniform approach. Extracts derived from 103 cells from the resi dual cells in the syringe were used for the telomeric repeat amplification protocol (TRAP) assay. Of the original 617 patients, 220 underwent open bio psy or surgery, and 93 cancers and 127 patients' benign diseases were diagn osed by histologic examination. RESULTS. All 62 tumors that were diagnosed as "malignant" or "probably mali gnant" by FNA cytology were cancerous, and 50 cases (81%) showed detectable telomerase activity. Among 17 "atypical" or "indeterminate" cases, all 10 tumors with detectable telomerase activity subsequently were diagnosed as b reast carcinoma whereas 6 of 7 tumors without telomerase activity were diag nosed as benign. Among the 141 "benign" or "unsatisfactory" samples, 12 of 21 cases with detectable telomerase activity subsequently were diagnosed as cancer. CONCLUSIONS. The diagnostic accuracy of telomerase activity in FNA samples is considered to be equivalent or slightly higher to that of cytology (86% vs. 70%). Detection of telomerase activity should be considered an alert fo r false-negative results of FNA cytology and may be useful as a diagnostic marker for breast malignancy, especially in samples cytologically undetermi ned to be malignant. Cancer (Cancer Cytopathol) 2000;90:235-8, (C) 2000 Ame rican Cancer Society.