The in vivo uptake of tritiated estradiol in carcinoma of the breast.

In human beings, the uptake of radiolabeled estradiol suppressed by carcinomatous breast tissue in vivo in relation to adipose breast tissue has been studied in 20 patients. The ratio of tumor uptake to fat tissue uptake was correlated with the age of the patient, menopausal status, presence of axillary metastases at time of mastectomy, and the response to endocrine therapy if metastases were presented. There was no correlation between a higher uptake of estradiol by the tumor and age of the patient, menopausal status, or presence of axillary metastases at time of mastectomy. Patients with a higher uptake of estradiol tended to respond favorably to endocrine treatment.