Validation of Cytokeratin 19, Mammaglobin A and B in detection of breast cancer cells in the bone marrow using a nested reverse transcriptase polymerase chain reaction (RT-PCR) assay

9672 Background: Early hematogenous spread of occult tumor cells is a crucial event in tumor progression and formation of distant metastases. Several markers mainly cytokeratins have been validated to date using immunohistochemistry (IHC) or more sensitive reverse transcriptase polymerase chain reaction (RT-PCR). The role of Cytokeratin 19 (CK-19) remains controversial regarding it's sensitivity and specificity. In contrast Mammaglobin was reported as a breast specific marker with very high specificity. In this feasibility study we validated expression of CK19, Mammaglobin A and B in the bone marrow samples of patients with breast cancer. Methods: We obtained bone marrow aspirates of 48 patients with stage I (38%), II (58%) and III (4%) breast cancer who underwent either immediate complete resection of the tumor or neoadjuvant therapy with subsequent curative surgery. mRNA was isolated using QIAamp RNA blood mini kit (Qiagen ®). Subsequently two-step nested RT-PCR for the expression of CK-19, Mammaglobin ...