[Clinical significance of RT-PCR in detection of axillary lymph node micrometastases from breast cancer].

BACKGROUND & OBJECTIVE: Recently, it has been reported that reverse transcription polymerase chain reaction(RT-PCR) for the detection of related tumor marker genes expression in lymph nodes can be used to evaluate tumor metastasis and results in higher sensitivity. The objective of this study was to investigate the clinical significance of RT-PCR for detecting axillary lymph node metastases of breast cancer. METHODS: RT-PCR was used to examine the mRNA of MUC1 and keratin19 in axillary lymph nodes. The lymph node metastases was assessed referring to the results of both RT-PCR and hematoxylin-eosin(HE) staining. All 37 patients with negative HE staining had been followed up for at least three years. RESULTS: Both MUC1 and keratin19 expression were detected in all 86 breast cancer specimens, while it was undetectable in all lymph nodes from patients with benign diseases. Among 37 patients with negative HE staining in lymph nodes, 11 were positive for keratin19 expression (29.7%), whose 3-year recurrence rate was 45.5% (5/11), while the patients with negative keratin19 expression was just 12.5% (2/26, P< 0.01). CONCLUSION: The expression of MUC1 and keratin19 in lymph nodes detected by RT-PCR can be regarded as a sign of breast cancer micrometastasis, which can be used to evaluate prognosis in patients as well as to choose the postoperative treatment protocols.