Mammaglobin B as a novel marker for detection of breast cancer micrometastases in axillary lymph nodes by reverse transcription-polymerase chain reaction

A novel reverse transcription-polymerase chain reaction (RT-PCR) assay usin g mammaglobin B gene was developed for detection of breast cancer micrometa stases in axillary lymph nodes. Fourteen primary breast cancers and 56 axil lary lymph nodes from six patients with primary breast cancer and 15 contro l lymph nodes from non-cancer bearing patients were subjected to this assay . The transcript of mammaglobin B gene was detected in none of the control lymph nodes, but in all of the 14 primary breast cancers. Eleven out of the 56 lymph nodes from the patients, which were shown to be positive by histo logical examination, were also proven positive by this assay. On the other hand, fourteen of the 45 (31%) histologically negative lymph nodes were als o shown to express mammaglobin B mRNA, which suggested the presence of micr ometastases in these lymph nodes. RT-PCR using mammaglobin B gene could the refore be a useful tool for detection of micrometastases of breast cancer.