Evaluation of the relationship between human epidermal growth factor receptor-2/neu (c-erbB-2) amplification and pathologic grading in patients with breast cancer.

OBJECTIVES The human epidermal growth factor receptor-2 (HER-2)/neu is a proto-oncogene that is amplified in 10-30% of breast cancers. It is known to be associated with a poor overall survival. We studied the relationship between its amplification and different histological gradings of breast cancer. METHODS We studied 196 patients diagnosed with breast cancer in 2005 at the Omid and Ghaem Training Hospital, Mashhad Medical University, Iran. The HER-2/neu oncoprotein was measured by immunohistochemistry and the histological gradings were carried out according to the Bloom-Richardson Grading system. RESULTS Sixty-seven (34.2%) cases were HER-2/neu positive and 129 (65.8%) cases were HER-2/neu negative. Overexpression of HER-2/neu was significantly higher in breast cancer patients <30 years (50% versus 33.3%, p=0.034). There was a non-significant statistical relationship between histological grading and overexpression of HER-2/neu oncogen (p=0.087). Twelve (17.5%) of HER-2/neu positive cases were metastatic and only 4 (3.1%) of HER-2/neu negative cases had metastasis (p=0.051). CONCLUSIONS HER-2/neu gene amplification or its overexpression is detected in approximately 34.2% of breast cancer cases. Patients with HER-2/neu positive breast cancer have higher stage and grade diseases. This may help to use a better treatment for patients.