[3H-thymidine incorporation under endocrine influence and hormone receptor content of human mammary carcinoma (author's transl)].

The effect of medroxyprogesterone acetate, oestradiol-17 beta and testolactone on 3H-thymidine incorporation in human mammary carcinoma was studied in vitro. 54% of the tumours reacted to medroxyprogesterone, while testolactone and oestradiol-17 beta changed 3H-thymidine incorporation in 45.1 and 41.3%, respectively. Both inhibition and the in vivo undesirable stimulation of 3H-thymidine incorporation was observed. No relation could be established between oestrogen receptor content and reaction of the mammary carcinoma to oestradiol-17 beta. On the other hand, the gestagen receptor content and the reaction of the mammary carcinoma to medroxyprogesterone acetate correlated significantly (P < 0.001). This underlines the increasing significance of the gestagen receptor in the selective endocrine treatment of mammary carcinoma.