In vitro adriamycin sensitivity test and hormonal receptors in primary breast cancer

Abstract

Cytoplasmatic estrogen (ER) and progesterone (PgR) receptors were determined by the dextran coated charcoal method in 90 primary breast cancer tissues. In parallel common intrinsic chemoresistance to cytotoxic drugs was examined, using a simple standardized in vitro short term predictive test ( 3 H-uridine incorporation adriamycin inhibition test). The in vitro response rate to adriamycin is negatively correlated to steroid receptor content, which was classified receptor-negative, -poor, and -rich. Estrogen receptor-negative cancers demonstrate an increased incidence of in vitro responses to adriamycin ( 23 38 compared to receptor-rich cancers ( 7 41 ). The same hold true for the relationship progesterone receptor content/ in vitro sensitivity to chemotherapy. Results are most clearcut in cases of identical (ER, PgR) receptor content, where response to adriamycin was observed in 17 26 receptor negative cancers against 1 12 with receptor positive specimens. These tools may predict prognosis of early recurrence following mastectomy, and may be useful in stratifying patients for individual adjuvant hormone and/or chemotherapy regimens.