Changes in estrogen and progesterone receptor levels after preoperative treatment of advanced primary breast cancer

Abstract

Using the dextran-coated charcoal method, estrogen and progesterone receptors were measured before and after preoperative treatment in 24 patients with advanced primary breast cancer. The average estrogen receptor level fell significantly (P<0.005) after preoperative treatment, while the average progesterone receptor level did not change significantly. There was no change of estrogen receptor or progesterone receptor status from negative to positive in any of the patients. The average pretreatment estrogen receptor level was higher in the responders than in the nonresponders. The average estrogen receptor level fell significantly (P<0.03) in the responders after treatment, but it did not change significantly in the nonresponders. These results demonstrate that quantitative data on hormone receptors are more useful clinically than qualitative data It appears that estrogen receptor levels in human breast cancer usually decrease or remain unchange after treatment and that receptor status does not change from negative to positive.