In recent years, there has been an unusual amount of conjecture as to the significance of the configurational similarity of the sex hormones, bile acids, vitamin D, cholesterol and the carcinogenic polycyclic hydrocarbons. Much speculation has been devoted particularly to the chemical relationship between the sex hormones and carcinogenic principles in the etiology of cancer. Sobotka1 quoted Cook, who stated that "the cell proliferation which characterizes the estrous state is in some respects reminiscent of the early stages of malignant growth," and Sobotka further conjectured that, while biodehydrogenation of sterols or bile acids may be the physiologic method for the production of the sex hormones, further dehydrogenation by a faulty mechanism may give rise to tumor-stimulating substances.
Sobotka and Bloch2 were unable to find any positive chemical or biologic evidence for the presence of carcinogenic hydrocarbons in large quantities of pooled urine from patients with cancer. However, they