Der mögliche Einfluß von Vitamin A auf die Krebsentstehung in der HNO-Heilkunde

Summary

Recently vitamin A has been shown to have an inhibitory effect on the carcinogenic potential of tobacco smoke constituents and vitamin A deficiency has been reported to be capable of reducing the tumor induction time in the respiratory tract of animals treated with polycyclic aromatic hydrocarbons. Prospectives epidemiological investigations have shown an inverse association between vitamin A and risk of lung cancer. We have done therefore histologic and electron microscopic investigations on the influence of a chronic vitamin A deficit diet on the epithelial structures of trachea in rats. Further we measured vitamin A, RBP and zinc in the blood in alcoholics, cancer patients and controls. After 12 week of a vitamin A deficit diet the male rats showed focal metaplasias. Mean levels of vitamin A in patients with alcoholic liver diseases and in patients with head and neck cancer and simultaneous alcoholic liver diseases were deceased compared to healthy controls and patients with head neck cancer without liver diseases. The mean levels for zinc and RBP were in the groups with liver diseases likewise decreased compared with the two others groups. We conclude that the chronic alcoholism leads to a vitamin A deficit in humans and this may be one cause for the higher risk for cancer in chronic alcoholics.