Transplantation of human cancers to nude mice and effects of thymus grafts.

Human cancers were transplanted to nude mice; a cell line originating in the foregut (distal stomach or first portion of the duodenum) produced exponential nonmetastasizing growth, preventable by prior thymus implantation. Implantation of thymuses into mice with established tumors resulted in increased animal survival and in four instances in complete regression of the neoplasm. Cell lines of pancreatic carcinoma and melanoma and surgical specimens of melanoma and of neoplasms from the pancreas and colon showed variable growth patterns in this system. Repeated attempts to transplant gastric adenocarcinoma were unsuccessful.