[Retinoids: use in combating cancer].

Retinoids are a group of natural and synthetic analogues of vitamin A (retinol). The biological activity of retinoids is mediated by multiple nuclear receptors which bind to specific DNA sequences and regulate transcription of target genes. Retinoids affect cell growth and differentiation. Retinoids inhibit chemically induced carcinogenesis in experimental animals. Clinical application of retinoids is efficacious to different degrees in prevention and therapy of some malignancies in humans, such as promyelocytic leukaemia, notably in combination chemotherapy. Unfortunately, lack of response, recurrence, toxicity and resistance are observed. Worldwide clinical trials have been set up to evaluate the treatment of mammary carcinoma with retinoids. It appears important to determine, before starting treatment, whether oestrogen or retinyl receptors are present in the tumor tissue.