Urinary Cholesterol in Cancer

The structural relation of several potent carcinogenic hydrocarbons to cyclopentenophenanthrene, which forms the cyclic portion of cholesterol, bile acids, and steroid hormones, has given rise in recent years to various speculations concerning the role which cholesterol and other steroid derivatives may play in tumor metabolism. However, there are also numerous carcinogenic aromatic hydrocarbons: of which the skeleton bears no obvious resemblance to cyclopentenophenanthrene. The obvious contrast between carcinogenic hydrocarbons and aromatic nitrogen compounds of carcinogenic action (p-aminoazotoluene, P-naphthylamine, etc.) in the route of invasion and in their mechanism of action speaks against a fundamental concatenat’ion between steroid metabolism and tumor growth. Yet, cholesterol is linked in some peculiar manner with tumor metabolism. According to numerous authors (1) tumor tissue is richer in cholesterol t’han any parenchymatous organ, exclusive of the brain perhaps.’ The cholesterol level in blood and serum of cancerous individuals has been the subject of innumerable studies (3), but owing to the effects of emaciation and cachexia and to the specific influence of the state of various organs on cholesterol metabolism, also owing to the prevailing ignorance concerning the physiological function of cholesterol, the results of such investigations have not yet found a conclusive and uniform interpretation. The cholesterol excretion through the kidney is minute under normal conditions, but considerable amounts are found in the