Mammaglobin mRNA measurement in the detection of micrometastasis in peripheral blood of breast cancer patients

Objective: To investigate mammanglobin (hMAM) mRNA as a marker for the detection of carcinoma cells by reverse transcriptase chain reaction (RT-PCR) in the peripheral blood of breast cancer patients.

Methods: Blood samples from 63 breast cancer patients obtained at various stages of their disease, blood samples from 8 breast hyperplasia, 5 breast adenofibroma, 25 other cancers (stomach, colon, esophagus, lung, ovary) and 31 healthy volunteers were screened for hMAM mRNA by a nested RT-PCR combined with fluorescence quantitative PCR (FQ-PCR) assay.

Results: Among 63 breast carcinoma patients, 19(30.2%) were RT-PCR positive for hMAM mRNA which was elevated with the tumor stage. None of the other cancer patients or those suffering from benign breast diseases were positive but only 1 of the 31 healthy volunteers gave detectable hMAM mRNA findings. hMAM mRNA was not detectable in the peripheral blood after operation in 6(32%) of 19 patients whose pre-operative test had been positive even though the hMAM mRNA expression increased with tumor stage. These results did not correlate with patients' stage, estrogen or pregnant receptor status.

Conclusions: hMAM transcripts are detectable in the peripheral blood of some breast cancer patients. hMAM may be a novel candidate and a clinically useful breast tumor marker, especially in detecting micrometastasis.