Mammaglobin as Molecular Marker of Breast Cancer (Micro)Metastases

Detection of Cytokeratin 19, Human Mammaglobin, and Carcinoembryonic Antigen-Positive Circulating Tumor Cells by Three-Marker Reverse Transcription-Pcr Assay and Its Relation to Clinical Outcome in Early Breast Cancer

Aims

To investigate the diagnostic, predictive, and prognostic value of the detection of circulating tumor cells (CTCs) using a three-marker (CK19, hMAM and CEA) RT-PCR assay in patients with early breast cancer.

Patients and methods

Peripheral blood was obtained from 50 patients with early-stage breast cancer before any systemic adjuvant therapy and analyzed for the presence of CK-19, hMAM and CEA mRNA-positive CTCs using an RT-PCR assay. The specificity of the primers used was evaluated in 20 healthy individuals, 24 patients with benign breast disease, and 30 patients with metastatic breast cancer. The detection of CTCs was correlated with clinical outcome.

Results

The detection rate of three-marker-positive CTCs in the blood of patients with early breast cancer was 54.0%, significantly higher than in patients with benign breast disease and healthy blood donors (p=0.002 and p=0.000, respectively). The three-marker RT-PCR assay had 58.8% sensitivity in the parallel test and 100% specificity for CTC detection in the serial test, which was higher than the sensitivity and specificity of single-marker assays. For early breast cancer, correlation analysis between detection of three-marker-positive CTCs and clinicopathological characteristics indicated that detection of three-marker-positive CTCs was significantly correlated with elevated serum CEA levels (p=0.001). After three years of follow-up, 13 of the 27 patients with three-marker-positive CTCs in their blood had relapsed and detection of three-marker-positive CTCs was significantly associated with locoregional recurrence and/or distant metastasis (p=0.002). Detection of three-marker-positive CTCs in peripheral blood was an independent risk factor for reduced median relapse-free interval (p=0.000).

Conclusion

The three-marker RT-PCR assay can enhance the sensitivity and specificity of CTC detection compared to single-marker assay. Detection of three-marker-positive CTCs was associated with relapse and might have important predictive and prognostic implications in early breast cancer.

The Clinical Utility of Circulating Tumor Cells in Breast Cancer Patients: Detection by a Quantitative Assay of h-MAM Gene Expression

The aim of this study was to evaluate tumor markers of molecular abnormalities that display tissue specificity, as to detect circulating tumor cells (CTCs) in breast cancer patients. Quantitative real-time RT-PCR was used to determine h-MAM, BCSG1, CK19, and c-erbB2 mRNA levels in peripheral blood (PB) of breast cancer patients. Results were compared with other epithelial cancers (lung or esophagus cancer), benign breast disease, and healthy individuals. We found that h-MAM mRNA was only detectable in the PB of patients with breast cancer (49 of 65, 75.4%), but not in patients with other epithelial cancers, benign breast disease, or healthy individuals. No significant differences in the expression level and positive detection rate of BCSG1, CK19, and c-erbB2 mRNA were observed between breast cancer and other epithelial cancers. Furthermore, the expression level and positive detection rate of h-MAM mRNA in PB were significantly correlated to the breast cancer pathologic stage (p=0.012 and p=0.015, respectively). Chemotherapy, radiotherapy, or total tumor resection (after 7 days of treatment) resulted in a significant decrease in the expression level of h-MAM mRNA in PB compared to the levels prior to the treatment (p<0.001). Importantly, an increase in h-MAM mRNA expression was detected in patients immediately after surgery, as well as 3 days post-surgery. These results indicate that the quantitative analysis of h-MAM mRNA is a useful tool for detecting CTCs in breast cancer patients, and can have a potential diagnostic utility in early micrometastasis, clinical evaluation of cancer treatment efficacy, and post-treatment monitoring of breast cancer patients.

Mammaglobin RT-qPCR for breast cancer metastasis detection in sentinel lymph nodes

(Cancer Sci 2010; 101: 2501)