Seed and soil revisited: contribution of the organ microenvironment to cancer metastasis.

The outcome of cancer metastasis depends on multiple interactions (cross-talk) between selected metastatic cells and homeostatic mechanisms unique to some organ microenvironments. The organ microenvironment can influence the biology of cancer growth, angiogenesis, and metastasis in several different ways. Therapy of metastasis, therefore, should be targeted against metastatic tumor cells and the homeostatic factors that are favorable to metastasis, growth, and survival of the metastatic cells.