Statistical analysis of hormonal effects on the steroid responsiveness of solid Ehrlich tumors.

Abstract

The influence of the gonads and adrenals on tumor growth was studied with SMA mice bearing solid Ehrlich tumors which have been produced by subcutaneous injection of ascitic Ehrlich tumor cells. It was found that the tumor growth was stimulated by the testes and inhibited by the ovaries and also by the administration of hydrocortisone acetate. The inhibitive effect of the adrenocortical hormone for tumor growth was observed only in male mice. The administration of testosterone and its two derivatives enhanced the tumor growth in castrated male and intact female mice, and estradiol suppressed it in intact male mice. A positive correlation for testosterone and a negative correlation for estradiol in the tumor response versus hormone dose were statistically significant. The diploid Ehrlich tumor was less responsive than the tetraploid Ehrlich tumor with respect to the effects of testosterone and hydrocortisone. In the statistical calculation with the tumor tissue, the logarithm of the tumor weight (growth index of tumor) was used in place of the tumor weight itself on the basis of the fact that the distribution of the former with 99 mice was normal, whereas the distribution of the latter with the same material showed a great deviation from the normal distribution.