Relation of glucocorticoid activity of steroids to number of metastases.

Summary Experiments were done to determine whether the effect of steroids in increasing metastases could be correlated with their glucocorticoid or mineralocorticoid activity. 6α, 9α-difluoroprednisolone (DFP), cortisone, and deoxycorticosterone (DOC) were tested for effects on metastases produced by intravenous injection of B16 tumor cells in C57/BL6 mice. Appropriate doses and times of administration were first determined. The maximum steroid effect on metastases appeared in those mice receiving 0.5 mg. of steroid 4–8 hours before the injection of tumor cells. Glucocorticoid activity was also assayed. Both DFP and cortisone increased metastases. DFP was more effective in increasing metastases than was cortisone, and DFP revealed more glucocorticoid activity. DOC did not increase metastases and displayed no glucocorticoid activity. A large dose of DFP did not increase metastases as much as a smaller dose, and the larger dose had less glucocorticoid activity. It is concluded that the capacity of a steroid to increase metastases is correlated with its glucocorticoid activity.