Selective tumor receptivity of the lung of newborn mice.

Introduction. Recent experiments in this laboratory dis closed the fact that when ascites tumor cells were injected intraperitoneally into newborn or suckling mice, not only were tumor ascites and peritoneal tumor nodules produced generally, but tumors appeared in the lung at high rates, provided that injections were made within three or four days after birth. Organs other than the lung showed no such receptivity to tumor transmission at any time. It is well known that newborn or young suckling animals are far more susceptible than adults to various infections and tumor transplantation, but we are not aware of any experi mental demonstration of the selective receptivity of the lung to tumor transmission during the early postnatal age. Material and Methods. Experiments were carried out with Sarcoma 180 and NTF-sarcoma of the mouse, both of the ascites form. The latter tumor is our "Friend-virus associated sarcoma," first reported in 1965 (2), which has since spon