The correlation of estrogen and progesterone receptor levels with response to chemotherapy for advanced carcinoma of the breast.

Estrogen and progesterone receptor levels were determined simultaneously in tumor samples obtained from 105 patients who subsequently received a trial of hormonal or chemotherapy for metastatic carcinoma of the breast. Twenty-three of 33 estrogen receptor positive patients in contrast with three of 22 estrogen receptor negative patients achieved an objective response to hormonal therapy. More significantly, it was found that 12 of 16 estrogen receptor positive patients compared with only six of 34 estrogen receptor negative patients responded to combination chemotherapy. Simultaneous measurement of progesterone receptor improved the selection of tumors responsive to chemotherapy, as only four of 30 patients who were estrogen receptor negative-progesterone receptor negative achieved a response. Furthermore, the cumulative survival time of 36 months after the first recurrence of carcinoma of the breast was significantly lower in estrogen receptor negative patients receiving chemotherapy. These data indicate that patients with estrogen receptor negative carcinoma of the breast are resistant to standard hormonal and chemotherapeutic measures for metastatic disease and carry a poor prognosis.