THE PREDICTIVE VALUE OF HUMAN EPIDERMAL GROWTH FACTOR RECEPTOR 2 (HER2/neu) FOR THE OUTCOME OF ANTHRACYCLINE-BASED ADJUVANT CHEMOTHERAPY IN EGYPTIAN HIGH RISK FEMALE BREAST CANCER PATIENTS
Ahmed N. Abd El-Aal1, Nashaat S. Lotfy2, Ehsan M. H. Abd Al-Rahman1, Suzan M. F. Helal3, Eman M. S. Kamha1, Doaa A. Abd Al-Monsif1, Mohammed S. Shaat4, Ahmed S. Anan4.
Departments of Medical Biochemistry1, Clinical Oncology and Nuclear Medicine2, Pathology3, and Undergraduate students4, Faculty of Medicine, Alexandria University, Egypt.
Introduction: Anthracyclines represent one of the most important chemotherapeutics in breast cancer. However, they cause cardiac damage besides some tumors might be anthracycline-resistant. Aim of the work: The aim of the present work was to study the predictive value of human epidermal growth factor receptor 2 (HER2/neu) protein, state (positive or negative) and score (0,1+,2+,3+), for the outcome of 5-fluorouracil / Adriamycin / cyclophosphamide (FAC) adjuvant chemotherapy in Egyptian high risk female breast cancer patients. Subjects & Methods: The present retrospective cohort study was conducted in Alexandria Main University Hospital, Egypt. It included fifty high risk female breast cancer patients (according to St Gallen guidelines 2007) with operable breast cancer. All of them have received FAC adjuvant chemotherapy between January 2007 and December 2007 and were followed for 2 years. Pretreatment breast tumor samples were obtained from formalin fixed/paraffin-embedded tissue blocks where HER2/neu protein was assessed by immunohistochemistry (IHC). Results: Kaplan-Meier survival analysis showed that positive HER2/neu state was associated with superior 2-year disease free survival (DFS) and overall survival (OS) rates to negative HER2/neu state but this difference was statistically insignificant (log rank p=0.08 and 0.24 respectively). On the other hand, there was a statistically significant difference between 2-year DFS rate of different HER2/neu protein score categories (log rank p=0.001*). Although being statistically significant, there was no pattern between HER2/neu protein scoring and DFS where score 0 showed intermediate DFS rate between scores 2+ and 3+. Moreover, Cox regression analysis showed that HER2/neu protein score couldn’t be an independent predictor for the outcome (DFS) of FAC adjuvant chemotherapy (p=0.66). Conclusion: HER2/neu protein mightn’t be considered as a predictor for the outcome of FAC adjuvant chemotherapy in Egyptian high risk female breast cancer patients. Consequently, large-scale prospective studies will be needed to clearly define its predictive value.