Biologic titration of diethylstilbestrol against activity of prostatic cancer: effect on serum aldolase.

THE concentration of a number of oxidative enzymes is reduced in various tumors. Greenstein (1) has indicated that catalase is absent in transplanted hepatoma. Other investigators (2, 3, 4) have shown amino acid oxidase, cytochrome C reductase and xanthine dehydrogenase to be present in decreased amounts in cancer. Schneider and Potter (5) reported that succinic acid dehydrogenase and cytochrome oxidase activities of rat hepatoma were only 22 to 30 per cent of those found in normal liver. There are only fragmentary data concerning the relationship of endocrine function to activity of these enzymes. Observations in this area are of particular interest as the endocrine control of cancer of the breast and prostate and certain of the leukemias becomes more apparent. Warburg's (6) studies on tumor metabolism disclosed a quantitative difference between normal and cancer tissue which as yet remains unexplained. Malignant cells have a high and characteristic rate of aerobic glycolysis. Warburg and Christian (7) a...