Differences of the growth of mouse teratocarcinoma OTT6050 induced by various sex hormone treatments in vivo.

To study why the tumor growth rate was different among host mice of different sexes and ages, we examined the role of sex hormones in the growth and development of mouse teratocarcinoma OTT6050 in vivo. Estrogen and progesterone showed enhancement of tumor growth, while ovariectomy resulted in partial growth inhibition. Testosterone, orchiectomy, and antiestrogen had no effects. We concluded that the differences in tumor growth rate in females of different ages were due to changes in serum estrogen and progesterone levels and that the constancy of the growth in adult males was due to absent effects of testosterone.