Approaches to Prevention of Epithelial Cancer during the Preneoplastic Period¹

The development of epithelial cancer is a disease process that takes many years to reach its final, invasive stage in humans. This disease process has the potential to be controlled by physiological or pharmacological means during its preneoplastic stages. Mechanisms whereby the progression of preneoplastic lesions can be stabilized, arrested, or reversed are discussed. Pharmacological enhancement of such mechanisms by synthetic vitamin A analogs (retinoids) offers a possible means for prevention of invasive epithelial cancer.