RESEARCH ARTICLE

Full list of author information is available at the end of the articleBackground The development of oral squamous cell carcinoma (OSCC) depends on both environmental and genetic factors. Most oral cancer cases have had prolonged ex-posure to tobacco and alcohol, but these carcinogens cannot fully account for the development of cancers in these individuals [1]. Numerous studies have shown that tobacco causes damage of the cell DNA and alcohol re-duces the effectiveness of DNA repairing that would be needed [2]. The accumulations of genetic abnormalities in carcinogenesis are divided into four phases: initiation, promotion, conversion and progression [3]. Cytogenetic analysis has detected an accumulation of genetic lesions in oral cancers [4]. Numerical changes in chromosomes 7 and 17 might be associated with an up-regulation of p53 gene, and could contribute to critical events in laryngeal carcino-genesis [4]. Moreover, human papillomavirus-associate