Last update:
10-Jan-2013

Squamous cell carcinoma of the head and neck (HNSCC) is one of the most common cancers worldwide. It has a rising incidence and is characterized by high mortality and it is frequently preceded by premalignant lesions, such as leukoplakia and erythroplakia. Various environmental factors have been implicated in its etiology, including tobacco and alcohol use and viral agents, and there is a genetic susceptibility. The acquisition of a malignant phenotype is a multi-step process that requires the accumulation of multiple genetic and epigenetic alterations. The steps include activation of oncogenes, inactivation of tumor suppressor genes and deregulation of various molecular pathways that control basic cellular functions such as cell proliferation, differentiation and apoptosis. In recent years new insights into the complex molecular mechanisms underlying the development of HNSCC have created new opportunities for the identification of appropriate biomarkers to facilitate early diagnosis of precancerous lesions and act as targets for individualized therapeutic interventions. This is a review of the molecular pathogenesis of HNSCC and the various aberrations of genes and signaling pathways that have been correlated with the malignant characteristics of invasion, angiogenesis, evasion of immune surveillance and metastasis. Field cancerization and cell immortalization are discussed together with the emerging role of human papilloma virus (HPV) in the disease. Finally, the implications of these new findings for the prevention and therapy of HNSCC are presented.

Key words: Head and neck squamous cell carcinoma, Molecular biology, Oral cancer, Targeted therapy.