ABSTRACT
This chapter reviews the current knowledge on the metastatic behavior of human tumors transplanted to nude mice; emphasis is put on the experimental models recently proposed for studying specific aspects of the metastatic process. Metastasis formation in cancer is possibly the most difficult aspect to control. Metastases in nude mice are usually not observed because of the short life span of the animals related to their poor health status or the large size of the xenografts. The poor metastatic behavior of s.c. transplants in nude mice has led to studies on the influence of the host in the control of other than T cell-dependent metastatic spread. The site of transplantation in nude mice seems to play a major role in the metastatic behavior of human tumors. Metastases have been reported in nude mice for the majority of human tumor types, but the lack of consistent results makes the model hard to use for experiments on this phenomenon.
