الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
HER-2 is a member of epidermal growth factor (EGF) family. The gene is located on chromosome 17q21 and encodes transmembrane growth factor receptor of 185 kilo Dalton (KDa). HER-2 gene over expression occurs in 20 to 30% of breast cancers and correlates with poor prognosis (Rubin & Yarden, 2001). Herceptin (also named trastuzumab) is a Food and Drug Administration (FDA) approved monoclonal anti-HER-2 antibody used as neoadjuvant or adjuvant therapy. This drug targets the extracellular domain of HER-2 receptor (Nahta et al., 2006& 2007). Herceptin decreases the recurrence by 40% and the mortality by 30%. Pertuzumab is another drug in use for BC treatment protocol in combination with Herceptin to prevent HER-2 dimerization by binding to its extracellular domain (Swain et al.,2020). Lapatinib is also a drug used for BC treatment, it inhibits the function of HER-2 in a different way by binding to the cytoplasmic ATP-binding sites of HER-2 receptors, thereby blocking tyrosine kinase (TK) phosphorylation (Tsang et al., 2015). Thus, a reliable HER-2 evaluation is a critical step for selecting patients for targeted anti-HER-2 therapies (Romond et al., 2007).