[Oral cancer: epidemiology and prognosis].
More than 90% of intra-oral malignancies are squamous cell carcinomas. Oral cancer is far more frequent in developing countries than in developed ones. This has probably to do with the differences in the use of tobacco and alcohol and with factors such as oral hygiene, nutrition and general resistance. Through an increased interest for epidemiological studies certain factors are suspected as carcinogenic. They can grossly be divided into chemical, physical and biological. Even though it is often hard to prove the real relation of cause to effect, one can no longer deny the detrimental role of tobacco, of many alcoholic drinks, of poor oral hygiene, of nutritional deficiencies, of short wave irradiation, and possibly of certain viruses. These factors must further be investigated because the overall prognosis of oral cancer is not very good. Determinant in survival are the volume of tumor present (surface and depth), its growth pattern, its localisation, eventual lymph node involvement and general hematogenic metastases, ... The overall five-year survival seems to range between 10% for T4N3 and 95% for T1N0 cases. Early detection and efficient prevention must therefore be encouraged.