Dynamics of human renal tumor colony growth in vitro.

Two-layer soft agar cultures from 26 patients with renal cell carcinoma, 21 renal primary lesions and 5 metastatic lesions, were evaluated for tumor colony formation using both dynamic growth curves and static single time point colony counting. Dynamic growth curves markedly increased the number of evaluable tumor cultures. There was no relationship between colony formation and TNM stage of the tumor or renal vein invasion. However, there was a significantly (p less than 0.02) higher rate of colony formation from younger (less than 50 y.) patients than from older patients. Only 2 of 5 tumors tested showed response to one or more cytostatic agents in vitro, both tumors showing response to Adriamycin and one to Cis-platin. Dynamic evaluation of tumor colony formation in soft agar may increase the clinical applicability of the human tumor cloning system both by increasing the number of evaluable cultures and by providing more information about the processes involved in tumor colony formation in vitro.