Selection of mRNA markers for detection of lymph node micrometastases in breast cancer patients.

The aim of this study was to search for specific and sensitive mRNA markers or a combination of markers for RT-PCR detection of micrometastases in axillary lymph nodes (LNs) from patients with breast cancer. LNs (n=177) from 17 patients were examined with Cytokeratin20 (CK20), melanoma-associated genes (MAGE1, MAGE3), carcinoembryonic antigen (CEA), prostate-specific antigen (PSA), mammaglobin (MGB1) and mammaglobin B (MGB2) as molecular markers. CK20, MAGE1 and MAGE3 were slightly positive in primary tumors and CEA, PSA, MGB1 and MGB2 were highly positive. MGB1 and MGB2 were 100% positive in HE-positive LNs while CEA and PSA were only 35.7% and 57.1% positive. MGB1 and MGB2 were also 30.1% and 17.8% positive in HE-negative nodes. Thus, MGB1 and MGB2 are specific and a combination of the two should be useful for detection of micrometastases in axillary LNs of breast cancer patients.