PTEN and VEGF: possible predictors for sentinel lymph node micro-metastasis in breast cancer.

INTRODUCTION: The loss of PTEN expression and VEGF overexpression has been found to be correlated with metastasis in breast cancer patients. Despite significant advances in micro-metastasis detection methods, little is known about the relationship between micro-metastasis and primary tumors. The purpose of this study was to assess the association of VEGF and PTEN expression with micro-metastasis in breast cancer. MATERIALS AND METHODS: As destination sites for micro-metastasis, we examined peripheral blood (BD), bone marrow (BM) and sentinel lymph node (SLN) from 53 breast cancer patients. Protein and gene expressions of VEGF and PTEN at the primary site were determined by immunohistochemistry (IHC). BD and BM samples were processed using immunocytochemistry (ICC). SLNs were examined by hematoxylin and eosin (H&E) staining and IHC. RESULTS: Percentages of the patients with micro-metastasis were 24.5% for BD, 56.6% for BM, 26.4% in SLN by H&E and 41.5% in SLN by IHC. VEGF overexpression was strongly correlated to loss of PTEN expression (P=0.001, r=-0.446). VEGF overexpression and loss of PTEN expression were significantly associated with SLN micro-metastasis by either H&E or IHC (P<0.001). On the contrary, there is no significant correlation between their expression and micro-metastasis in BD and BM. CONCLUSIONS: Our results indicate possible value of using these biological markers to predict the risk of micro-metastasis in breast cancer.