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Cancer incidence in humans has gradually increased over the last century. Surgical, radio, chemotherapeutic and biological treatments have experienced important advances, with concomitant reduction in the morbidity associated with the radical surgical practices of the past. The term “oral cancer” includes a diverse group of tumors arising from the oral cavity (Khalili, 2008). Usually included are cancers of the lip, tongue, pharynx, and oral cavity. The World Health Organization (WHO) reported oral cancer as having one of the highest mortality ratios amongst all malignancies (Parkin et al., 2000). Although oral cancer is rare and attracts little attention, it is more common than Hodgkin’s disease tumours of brain, liver, bone, thyroid gland, stomach, ovaries, or cancer of the cervix. It ranks 12th among all cancers (Jemal et al., 2002). The vast majority of malignant neoplasms in the mouth are squamous cell carcinomas. Oral cancer incidence and mortality rates vary widely across the world. Mortality rate is an important tool that provides implicit information about incidence, diagnosis stage, solving capacity of health services, available technology and health programs to be applied. Although globally oral cancer represents an incidence of 3% (males) and 2% (females) of all malignant neoplasm, it has one of the lowest survival rates — 50 percent, within a five-year period (Greenlee et al., 2001). |
