Human Epidermal Growth Factor Receptor-3 mRNA Expression as a Prognostic Marker for Invasive Duct Carcinoma not Otherwise Specified XC01-XC05
Dr. Asmaa Gaber Abdou,
Department of Pathology, Faculty of Medicine, Menoufia University, Gamal Abd Elnaser Street,
Shebein Elkom-32511, Egypt.
Introduction: Breast cancer is the most common cancer in women and the Erythroblastosis Oncogene B(ErbB) receptor family holds crucial role in its pathogenesis. Human Epidermal Growth Factor Receptor 3 (HER-3) gene over expression in breast tissue has been associated with aggressive clinical behaviour and bad prognosis.
Aim: To evaluate HER-3 mRNA expression level as a prognostic marker for breast cancer and to correlate its level with other established prognostic parameters.
Materials and Methods: This study was carried out on specimens of 100 cases that were divided into 40 patients presented with fibroadenoma and 60 patients presented with Invasive Ductal Carcinoma (IDC) not otherwise specified and underwent modified radical mastectomy. All specimens were investigated for HER-2/neu, ER and PR expression by Immunohistochemistry (IHC) and quantitative assay of HER-3 mRNA expression using real time PCR technique.
Results: There was a significant high HER3 mRNA level in carcinoma cases compared to fibroadenoma. In malignant cases, HER3 mRNA level was significantly associated with advanced T stage, advanced N stage, number of positive lymph nodes, large tumour size and cases associated with an adjacent in situ component. Moreover, HER-3 mRNA level was of highest values in Her-2/neu positive group followed by triple negative cases with the lowest level in luminal group (p<0.05).
Conclusion: HER-3 gene is upregulated in IDC especially those carrying poor prognostic features. HER-3 mRNA level may identify a subset of patients with a poor prognosis, and who could undergo further evaluation for the efficacy of HER3 targeted anticancer therapy.