ABSTRACT
Oral cancer is a highly common malignant tumor of the oral cavity and the 10th most frequent common cancer in the world. The most frequent malignancy is oral squamous cell carcinoma (OSCC), which constitutes more than 90% of the oral malignancies and which has poor prognosis due to therapy-resistant locoregional recurrences and distant metastases (Rajendran and Sivapathasundharam 2012). OSCC is defined as a neoplastic disorder in the oral cavity and is a complex malignancy, where environmental factors, viral infections, and genetic alterations most likely interact and thus give rise to the malignant condition. Development of oral cancer proceeds through epigenetic alteration and discrete molecular genetic changes that are acquired from the loss of genomic integrity after continued exposure to environmental or dietary risk factors (American Cancer Society 2010).
