HER2 Protein Overexpression in Infiltrating Ductal Carcinoma of the Breast Associated with Lymph Node Involvement

The current study compares the rates of overexpression of the HER2 protein in stage II ductal carcinoma of breast in patients with lymph-node involvement. The research material was tissue sections obtained from the primary tumor of 28 patients with lymph-node involvement. The technique used to detect the protein was immunohistochemistry. The overexpression of HER2 protein occurred in 33.3% of lymph node-positive patients. Subsequently, the lymph-node metastases population was divided into two subgroups: one subgroup having involvement of up to three lymph nodes and the second subgroup with the involvement of four or more lymph-nodes. In the first group the level of HER2 overexpression was 7.7% and in the second subgroup the HER2 overexpression was 63.6%. The difference was statistically significant.