Experience with a simple method for estrogen receptor assay in breast cancer.

A simple procedure for the assay of specific estrogen receptors in breast cancer tissue is described. Estrogen receptors were detected in 74% of primary tumors, 71% of skin metastases and 63% of lymph node metastases. Postmenopausal patients and younger oophorectomized women had estrogen receptor-containing tumors more frequently, and at higher levels, than uncastrated, premenopausal, patients. The stability of estrogen receptors was not affected by the transportation of samples from distant hospitals, providing that they were kept frozen in Tris buffer, pH 8.0, at all times.