Cytokeratin 19 mRNA concentration in lymph nodes as a diagnostic marker of metastases

Comparison of the sensitivity of cytological and molecular genetic methods (19 specimens of lymph nodes from 8 patients with breast cancer and suspected metastases obtained by transcutaneous fine-needle aspiration biopsy under ultrasound guidance) showed that molecular genetic and cytological studies produced true results in 95 and 84% specimens, respectively. True-positive and true-negative results were obtained in 8 and 7 patients, respectively. Expression of cytokeratin 19 was detected in 3 specimens with negative cytological results and confirmed metastases in lymph nodes. Our results indicate that molecular genetic diagnostic study for lymph node metastases should be used in small amounts of biopsy specimens, presence of marginal metastases in lymph nodes, and negative results of repeated cytological examination.