Aim: This study was to investigate the E-cadherin expression patterns in primary breast cancers and metastatic lymph node.
Methods: Only lymph nodes which were pathologically identified as metastases were included in this study to pair up the primary tumors. E-cadherin RNA expression levels in invasive ductal breast cancer subjects were detected. E-cadherin gene copies were normalized using beta-actin gene copies. ER, PR, cerbB2 expressions in the primary tumor were routinely examined by immunohistochemistry method. Tumor characteristics and number of metastatic lymph nodes were gathered from the pathology reports.
Results: We tried to explore the relationship between E-cadherin expression in 21 primary tumors and their corresponding metastatic lymph nodes. However, the Q-RT-PCR data show that an aberrant expression existed in both primary tumors and the corresponding lymph nodes (P=0.115), in which metastatic lymph nodes showed slight higher gene copies compared with primary sites (77.77±94.74 vs 43.35±40.03, respectively). It is noteworthy that nodal E-cadherin expression was closely but negatively correlated with tumor size (P<0.01, r=-0.775) and number of metastasized lymph nodes (P<0.05, r=-0.519), as tumor size and number of metastasized lymph nodes were already clinically proven to be important prognostic factors. There was no correlation between ER, PR, cerbB2 status in primary tumors and the nodal E-cadherin expression (P>0.05).
Conclusions: It is indicated that E-cadherin expression is aberrant in invasive ductal cancers and their corresponding metastatic lymph nodes. E-cadherin expression in the metastasized lymph node is closely related to tumor size and number of metastasized lymph nodes.
Keywords: E-cadherin; metastatic lymph node; primary breast cancer; real-time PCR.