[Vitamin A acid for the topical management of epithelial neoplasms. Combination with 5-fluorouracil]

15 patients with superficial basaliomas or premalignant epithelial neoplastic disorders (actinic keratosis, leukoplakia, Bowen's disease) were treated locally over three weeks with retinoic acid (RA) alone or in combination with 5-fluorouracil (5-FU). In 11 cases the lesions disappeared clinically, however, only 5 patients proved to be cured by histological examination. 4 of them were treated with RA combined with 5-FU. There was a decrease of the 3H-index after the first week and an increase after the third week of treatment. These findings suggest, that RA inhibits the proliferation of neoplastic keratinocytes and stimulates the proliferation of normal epidermal cells. Retinoic acid, therefore, has an inhibitory effect on epithelial neoplasias, particularly in combination with 5-FU. Since local therapy with RA and 5-FU is not sufficient for routine clinical purposes in all cases, their use should be restricted to selected patients.