Results and merit of estrogen receptor data derived from metastatic tumors of the breast.

It is clear that a variety of metastatic deposits can successfully be assayed and found to contain estrogen receptor protein even up to 13 years following the initial tumor surgical procedure. Whether or not the patient has received previous treatment, estrogen receptor status does not appear to be influenced, and biopsies of the 23 metastatic lesions were found to contain estrogen receptors. Fourteen of nineteen patients with metastatic tumors containing estrogen receptors who were treated and evaluated demonstrated remission after hormonal manipulation. Only one patient with a tumor with no estrogen receptors demonstrated tumor regression after hypophysectomy and suggests that a previous response to hormone manipulation may warrant a further trial even when estrogen receptors are not found. The results of estrogen receptor values on metastatic disease of the breasts are extremely valuable in the therapeutic decision making process and should be routinely obtained.