Clonal selection of metastasis within the life history of a tumor

In summary, this Point-Counterpoint has focused on the hypothesis of clonal selection and the need to study a metastatic hypothesis within the life history of a tumor. Further, we stress the criticality of studying metastasis using suitable models, experimental strategies, and protocols. In addition, the metastatic process needs to be studied in vivo and within the context of host-tumor interactions and the life history of a tumor, as well as orthotopic, spontaneous metastases (6, 8). Despite the controversy about the clonal selection hypothesis, we hope we have shown that this powerful hypothesis remains strongly supported by data and is even more relevant to tumor biology when viewed in light of the life history of tumors. ©2007 American Association for Cancer Research.