Inhibitory Effects of Ethyl Carbamate on Prostatic Cancer

Abstract

Observations which prove an effect of ethyl carbamate on prostatic cancer are reported. It is a toxic drug which inhibits some cases of prostatic cancer. In 3 patients with widespread prostatic cancer, it caused considerable regression of the primary tumor, relief of pain, an improved sense of well-being, and a marked decrease of the acid phosphatase of the serum. In a 4th patient, 9 g./day given for 33 days had a fatal effect. In another patient with an advancing prostatic cancer, 4 g. given daily for 5 days followed by a maintenance dose of 1 g. daily for 6 wks., eliminated pain and caused considerable tumor regression. The therapy should be discontinued when the white count is under 4,000/ c.mm. or when nausea and vomiting occur. The favorable effects of ethyl carbamate are not a result of antiandrogenic action. A prostatic isolation operation was done and prostatic secretion collected every 2 days in 3 castrate dogs which received 10 mg. of testosterone propionate and 4-8 g. of ure-thane daily for 31 days; the secretion increased steadily, showing androgenic effects were not eliminated. Ethyl carbamate does not inhibit glycolysis. In concns. up to 0.005 M it had no effect on the rate of anerobic glycolysis in cell-free brain extracts supplemented with glucose and the system descr. by Utter, Wood, and Reiner (1945). Ethyl carbamate tends to suppress the transplantable Sarcoma 39 of rats. The tumor was inoculated subcut. in 26 rats and 0.5-1 mg./g. of ethyl carbamate was injected daily for 7 days and then every 2 days for 14 days; 21 control rats were inoculated but not given urethane. None of the exptl. group and 12 of the controls developed neoplasms. To determine the effect of malnutrition, 8 rats were inoculated with the tumor and starved for 14 days; 4 developed tumors on the 9th-13th day.