Reviewing the oral carcinogenic process: key genetic events, growth factors and molecular signaling pathways (original) (raw)

Squamous Cell Carcinoma of the Head and Neck (SCCHN) represents the sixth most common cancer and may involve the oral cavity (OSCC) as well as the larynx and pharynx, resulting in high mortality (5year survival rate is approximately 50%) despite molecular and therapeutical advances (Parkin et al., 2005). Although genetic predisposition, tobacco, alcohol, betel nuts use and Human Papilloma Viruses (HPV) infection are well recognized risk factors, the lack of established markers for early detection of OSCC in precancerous dysplastic lesions and the limited response to chemotherapy does not allow improvement of overall prognosis (Bagan & Scully, 2008). In fact, the mapping of genetic and epigenetic mechanisms underlying the malignant progression of OSCC is incomplete (Kim & Califano, 2004) and the exact turning point for the oral epithelium remains to be clarified. Current data support the hypothesis that neoplastic cells derive from the clonal expansion of a single (somatic epithelial...