RESUMO
BACKGROUND & OBJECTIVE: The major cause of death in breast cancer patients is distant metastasis. This study was to explore the expression and significance of small breast epithelial mucin (SBEM) mRNA, the specific marker of breast cancer, in peripheral blood of breast cancer patients. METHODS: Expression of SBEM mRNA in peripheral blood samples from 67 breast cancer patients, 16 benign breast disease patients, and 20 healthy volunteers was detected by nested reverse transcription-polymerase chain reaction (nested RT-PCR). RESULTS: SBEM mRNA was not detected in healthy volunteers and benign breast disease patients. Positive rate of SBEM mRNA was 50.7% (34/67) in breast cancer patients. Positive rate of SBEM mRNA was 25.0% (2/8) in stage I patients, 45.8% (11/24) in stage II patients, 43.8% (7/16) in stage III patients, and 73.7% (14/19) in stage IV patients, respectively. Positive rate of SBEM mRNA was significantly higher in stage IV patients than in stages I, II, and III patients (P0.05). The expression of SBEM mRNA in peripheral blood was not correlated with patient's age, primary tumor size, pathologic type, and estrogen or progestin receptor status (P0.05). CONCLUSION: SBEM mRNA is specifically expressed in peripheral blood of breast cancer patients, and may be a marker of micrometastasis of breast cancer.
