Note on the reëstablishment of a tendency to metastasize in a Flexner-Jobling carcinoma

Abstract

Owing to a misunderstanding on the part of the attendant, our strain of Flexner-Jobling tumor, which had been carried through nine generations since our experiments with cholesterol, 1 was destroyed during the Christmas holidays (1913). In order to repair this serious loss, we asked Dr. Peyton Rous for a new supply, that we might have tumors for future work. He very cordially responded to our demands, as was to be expected, but informed us that his strain had never metastasized, and expressed doubt as to the value of the tumors on that account.

February 21, 1914, we inoculated forty-seven white rats with the new tumor, which was Rous's twenty-first generation, new series. On March 14, thirty-nine, or eighty-three per cent., had well-marked tumors. Twenty-six of these were kept as “stock” and also served as controls, while thirteen were injected four times, at intervals of two or three days, with one cubic centimeter of a 2 per cent. emulsion of cholesterol. The injection was made on the opposite side to that of the tumor inoculation. By April 11 the tumors began to break down, and we were therefore obliged to kill some of the animals. By May 15 all had been killed. A post mortem was made on each rat, and the results were as follows:

A portion of one of these metastases was fixed and sectioned in the usual way, and the diagnosis confirmed microscopically by Professor G. Y. Rudk, of the department of pathology. In addition, seven rats were inoculated with pieces of a metastatic tumor from the mediastinum, and in fourteen days all had developed well-marked tumors.

Two facts seem evident. The tumor has again become a metastasizing tumor, and treatment with cholesterol has increased that tendency. The results from the treatment with cholesterol were to be expected from our former experiments.