[Current status of the use of vitamins (A, E, C, D), folates and selenium in the chemoprevention and treatment of malignant tumors].

The role of vitamins A, E, C, D, folates and selenium in the chemical prevention of tumours and/or precancerous conditions is examined in the light of epidemiological studies and experimental observations. Particular mention is made of significant clinical studies that provide valuable indications about the use of vitamin A and its derivates in particular for the treatment of precancerous and cancerous conditions. Vitamin A and its derivates apparently play a fundamental role not only in the treatment of proliferating malignancies of the skin (carcinomas, severe aclinic keratosis) or involving the skin (fungoid mycosis, skin metastases of solid tumours) but also in the prevention of recurring bladder tumours and the treatment of several bronchial dysplasias.