On secondary transplantation of a sarcoma of the rat

Abstract

At a meeting of the Society held on October 17, 1906, we presented specimens of a sarcoma of the rat which was being transplanted successfully. 1 In the course of the transplantations the percentage of successful issues has reached approximately one hundred. In many series, every transplanted fragment developed into a tumor, and in none of the latter series has the percentage of “takes” fallen below ninety. The tumor having reached this maximum of infectivity, it was thought desirable to ascertain to what extent secondary transplantation would succeed. The method followed was to inoculate rats, in which a tumor nodule was already present, with another fragment of the tumor tissue. The second inoculation was made, as a rule, on the side of the body opposite the existing nodule, but in a few cases it was made in the tissues adjacent to the first nodule. After the second growth had developed to the size of a pea or bean, the rats were killed in order to determine whether metastasis from the first inoculation had taken place. The results of this series of experiments show that secondary inoculation succeeds in a high percentage of the rats in which no visible metastases can be seen, and in which visible metastases, in the lungs chiefly, are present. The exact figures will be given in the complete publication to be issued soon.

The results of this series of experiments bear upon the view expressed by Sticker, that a primary tumor protects the body from the development of a secondary tumor until the period of metastasis arrives, and upon Ehrlich's negative results in secondary transplantations of a rapidly growing mouse carcinoma. The sarcoma or and experiments is characterized by its infiltrative growth, but it increases far less rapidly than the most active of Ehrlich's tumors, and reaches, in relation to the size of the rat, no such large size as the latter does in proportion to the size of the mouse.