Studies of the growth of a murine renal cell carcinoma and its metastatic patterns.

Metastatic lung tumor cells from a murine renal cell adenocarcinoma were implanted in Blab/C mice for 12 transfer generations. Survival time of the implanted mice was observed to decrease from 48 days to 28 days. The incidence of lung metastases increased from 40% to 90%. These studies suggest a selection process under the terms of the experiment that has resulted in a change in the metastatic potential of the primary tumor and its serial passage of metastases. The results are compatible with current concepts regarding cell selection in this cancer state but do not, at the present time, precisely define how this is achieved. Appropriate and selective studies are ongoing to address this important issue.