[Update review on prevention and early diagnosis in oral cancer].

Abstract

Oral cancer is a major health problem in some parts of the world, especially in developing countries. Worldwide, the annual incidence exceeds 3,000,000 new cases. The main risk factors are tobacco and alcohol. However, dietary factors, viruses and possibly genetic predisposition have also been associated with oral cancer. Several oral lesions such as leukoplakia, erythroplakia and lichen planus carry an increased risk for malignant transformation in the oral cavity. Prognosis of oral cancer differs significantly between specific oral locations, with cancer of the lip for example having a much better prognosis than at the base of tongue or on the gingiva. Prognosis of intra-oral cancer is generally poor, with a five-year survival less than 50 percent. Local recurrences as well as lymph node metastases occur in a significant percentage of patients, while distant metastases are less frequent. Prognosis correlates mainly with the size of the lesion and the nodal status at the time of diagnosis, therefore early detection of small, stage-1 oral cancer can reduce mortality and morbidity. Oral lesions can be easily observed by direct visualization, however, knowledge of the differential diagnosis of oral lesions is mandatory for early diagnosis of malignant and pre-malignant lesions in the oral cavity. Use of screening and detection aids such as vital stains and Oral CDX can increase the number of cases diagnosed at an early stage, or even in the pre-malignant stage. Development of molecular markers can improve the early diagnosis and can help in predicting treatment response. New treatment modalities including tumor specific antibodies and gene therapy are emerging, giving more hope for patients with oral cancer. There is an important role for the dentist in both early diagnosis of pre-malignant and malignant lesions, and in prevention by educating the patients of the risks associated with tobacco, alcohol and dietary factors.