Heterotransplantation of human neoplasms

The heterotransplantation of 39 solid human neoplasms into athymic and asplenic-athymic mice resulted in the successful growth of 28 of the transplants. However, only 17 of the tumors could be maintained in serial passage. Metastasis or local infiltration by the transplanted tumors was not observed. Melanomas and colorectal carcinomas grew well whereas other types grew poorly or not at all. Possible factors responsible for the poor growth or lack of growth are discussed. The rapid growth of a melanoma in newborn mice in contrast with the slow growth of the same tumor in adult mice suggests a new experimental approach for transplantation of malignancies which previously have been difficult to establish.