The demonstration of nonlinear development of experimental lung tumor metastases.

The kinetics of tumor colony formation in the lungs of mice following intravenous inoculation of high and low metastatic cell variants was determined. We have utilized two different tumor systems, the B16 melanoma, and UV-2237 fibrosarcoma; in both tumors the highly metastatic cell variants developed lung metastases in a nonlinear fashion following i.v. inoculation. The possibility that highly metastatic cell variants differ from their low metastatic counterparts not only in their lung colonizing potential, but also in their capability to produce satellite colonies, is discussed.