Correlation Between HER-2 Gene Amplification or Protein Expression and Clinical Pathological Features of Breast Cancer.

Abstract

The incidence of breast cancer in females is gradually increasing. Expression of HER-2 gene and protein is critical for predicting the prognosis of breast cancer. This study examined amplification of HER-2 gene and protein expression in breast cancer patients to analyze their correlation with clinical and pathological features. Specimens of breast gland tissues were collected from breast cancer patients for measuring HER-2 protein expression by immunohistochemistry (IHC) method. Fluorescent in situ hybridization (FISH) measured HER-2 gene amplification. The consistency of HER-2 protein and gene expression was analyzed in addition to their correlation with clinical and pathological features of patients. Thirty-six percent patients showed negative expression of HER-2 protein, and 9%, 32%, and 23% of them had positive expression to different levels (+, ++, and +++). Forty percent patients were positive for HER-2 gene amplification, including 3, 21, and 14 cases of (+), (++), and (+++) patients. Expression of HER-2 protein was highly correlated with HER-2 gene amplification (r = 1.262; p < 0.05). Both parameters were correlated with tumor size, differentiation grade, lymph node metastasis, and TNM stage (p < 0.05). Combined assay of IHC and FISH for detecting HER-2 protein or gene amplification in breast cancer tissues showed their correlation with tumor size, differentiation grade, lymph node metastasis, and TNM stage.