Since the beginning of the clinical trial of the prophylactic or adjuvant treatment of cancer, we have been searching for topical anticancer agents which were not bone-marrow depressants. Such agents could be used locally (topically) for wound irrigation to kill cancer cells but would not add to the depression of the hematopoietic system caused by concomitant systemic use of anticancer drugs, such as mechlorethamine hydrochloride, N. F. (nitrogen mustard). In the experimental laboratory we had found that mechlorethamine and triethylenethiophosphoramide (ThioTEPA), both polyfunctioning alkylating agents, were effective in preventing the implantation of tumors in the liver following intraportal injection of tumor-cell suspensions.1 As a result of this experimental work, we chose mechlorethamine as the agent to be used in the clinical trials of the administration of anticancer agents to the patient at the time of surgery. In other experimental work2 we had determined that mechlorethamine, when diluted properly,