Asian Pacifc Journal of Cancer Prevention, Vol 14, 2013 6415 DOI:http://dx.doi.org/10.7314/APJCP.2013.14.11.6415 Expression of EGFR and p53 in Head and Neck Tumors among Sudanese Patients Asian Pac J Cancer Prev, 14 (11), 6415-6418 Introduction Head and neck cancer comprises malignancies arising in the upper respiratory and digestive tracts and is a relatively frequent type of cancer (Parkin et al., 2002). Thus, the term “head and neck cancer” includes lesions at several anatomic sites, such as the lip, oral cavity, nose and paranasal sinuses, naso-pharynx, oro-pharynx, hypo- pharynx, larynx, oesophagus, salivary glands, as well the soft tissues of the neck and ear. The malignant tumors of the head and neck consist of a rather heterogeneous group of neoplasias arising in the epithelium of the upper aerodigestive tract. The most common histologic type is squamous cell carcinomas (SCC), occurring in the oral cavity, pharynx (nasopharynx, oropharynx and hypopharynx) and larynx (Lassen, 2010). Head and neck squamous cell carcinoma (HNSCC) is the seventh most commonly diagnosed cancer worldwide (Ferlay, et al., 2010) and is associated with survival rates. Its incidence varies widely among different regions. In North America and Europe, HNCs accounts for 3-4% of all cancer diagnoses. Conversely, in Southeast Asia and Africa, HNCs accounts for approximately 8-10% of all cancers (Santarelli et al., 2009). HNCs have traditionally been linked to alcohol and tobacco abuse (Goon et al., 2009). However, 15-20% of HNCs cases have no known tobacco or alcohol exposure (Gillison and Shah, 2001; Jo et al., 2009) thus, other agents, such as viruses, are being investigated. It is now evident that a signifcant proportion of HNSCCs are caused by HPV (Chung and Gillison, 2009). 1 Department of Histopathology and Cytology, Faculty of Medical laboratory Sciences, Elneelain University, Sudan, 2 Medicine, University of Hail, Kingdom of Saudi Arabia *For correspondence: Hussaingad1972@yahoo.com, he.ahmed@uoh.edu.sa Abstract Background: The aim of this study was to assess EGFR and p53 expression in head and neck tumors among Sudanese patients using immunohistochemistry. Materials and Methods: A retrospective descriptive study was performed on 150 samples from patients diagnosed with HNCs as well as 50 from individuals with benign head and neck tumors. EGFR and p53 expression was assessed using immunohistochemistry (IHC). Results: EGFR was expressed in 126/150 (84%) of HNCS and 6/50 (12%) benign head and neck tumors where as p53 was expressed in 29/150 (19.3%) of HNCs and 2/50 (4%) of benign head and neck tumors, with signifcance at p values of 0.001 and 0.009 respectively . Conclusions: There is a signifcant association between EGFR, P53 expression and head and neck cancers among Sudanese patients, . Keywords: Head and neck cancer - Sudanese - EGFR - p53 RESEARCH ARTICLE Expression of EGFR and p53 in Head and Neck Tumors among Sudanese Patients Mustafa Saadalnour Abusail 1 , Ahmed Mohmed Ahmed Dirweesh 2 , Rashid Awad Abdalla Salih 2 , Ahmed Hussain Gadelkarim 2 * Epidermal growth factor receptor (EGFR), it is a ubiquitously expressed transmembrane glycoprotein in the ErbB/HER family of receptor tyrosine kinase. These receptors are composed of an extracellular ligand-binding domain, a hydrophobic transmembrane segment, and an intracellular tyrosine kinase domain. Binding of natural ligands (amphiregulin and transforming growth factor alpha (TGF-α) in head and neck cancer) to EGFR results in a conformational change in EGFR. This promotes homo- or heterodimerization with other ErbB/HER family of receptors with subsequent autophosphorylation and activation of the tyrosine kinase (Ciardiello et al., 2003). This activation of EGFR leads to the initiation of intracellular signaling pathways which regulate the activation of cell proliferation, invasion, angiogenesis, and metastasis. High expression of EGFR occurs in most epithelial malignancies including head and neck squamous cell carcinoma (HNSCC) (Ciardiello et al., 2003). Over- expression or mutation of EGFR is found in 80-100% of the patients with HNCSCC, and both are associated with poor prognosis and decreased survival (Bonner et al., 2006; Hoffmann et al., 2009). p53, it is a tumor suppressor and ‘guardian of genome’, plays a critical role in apoptosis, cell cycle control, DNA damage response, host resistance to carcinogens, and cellular anti-cancer mechanisms. Upon DNA damage, which usually results from chemical carcinogens, chemotherapeutic drugs, irradiation or endogenous stressors, p53-mediated pathways attempt to repair the injury through cell cycle arrest and DNA repair (Lukas et al., 2004). To eliminate threat of tumorigenesis, p53