The molecular biology of oral carcinogenesis: toward a tumor progression model.

PURPOSE: An understanding of the molecular basis of oral carcinogenesis will alter our clinical approach to oral cancer. The nomenclature and major themes of molecular oral tumor biology are reviewed, beginning with the regulation events governing normal cellular physiology. In carcinogenesis, chromosomal or cytogenetic alterations lead to deregulation of tightly controlled stimulatory and inhibitory pathways, growth-promoting proto-oncogenes are mutated into overactive oncogenes, and growth-suppressing or tumor suppressor genes are inactivated. Recent advances in defining these fundamental mechanisms of tumor biology may allow prevention, diagnosis, and treatment of oral cancer to be approached at the molecular level.