Prognostic significances of estrogen and progesterone receptors in primary operable breast cancer.

Both estrogen and progesterone receptors have been determined in 613 primary breast cancer patients treated by radical mastectomy. At the cut-off value of 5 fentomoles (fmol) cytosol protein/mg for both receptors, patients with estrogen or progesterone receptor-positive breast cancer showed significantly favorable disease-free, overall and post-recurrence survival curves to those of receptor-negative breast cancer patients. In the patient subgroups: premenopausal, stage III, more than four positive lymph node metastases, postoperative adjuvant tamoxifen therapy, a significantly favorable prognosis was recognized in either estrogen or progesterone receptor-positive patients. Both receptors are thought to be useful prognostic indicators for patients with advanced tumors or for those receiving postoperative adjuvant tamoxifen therapy. When the cut-off value was changed, the maximum significant difference in prognosis between receptor-positive and receptor-negative patients was observed at 5 fmol cytosol protein/mg for the estrogen receptor or 10 fmol/mg cytosol protein for the progesterone receptor. A more detailed examination should be made on the cut-off values of both receptors.