Abstract
The extent of the relationship between hormone dependence and cytostatica sensitivity of the tumors was examined for primary breast cancers under standardized in vitro conditions. The effects of estradiol and adriamycin on the RNA biosynthesis in the tumor cells were compared on the basis of the 3H-uridine incorporation in a short-term test system. Estradiol particularly influenced the RNA metabolism of higly differentiated carcinomas, whereas adriamycin exhibited the greatest inhibitory effect on the RNA synthesis in the tumor cells of undifferentiated carcinomas. An exact, unequivocal separation of the breast cancers investigated into hormone-sensitive, cytostatica-resistant and hormone-independent, cytostatica-sensitive tumors, however, was not possible under the in vitro conditions chosen.