Objective: 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).
Conclusion: 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.