Hormone receptors in breast cancer

Abstract

Many advance have been made in the field of steroid receptor science and its application to new treatment approaches. The gaps in our knowledge of receptor mechanisms have narrowed over the past decade. Some gaps remain to be bridged, as, for example, in the area of nuclear acceptor sites for ER. The total import and role of some receptors, such as prolactin and vitamin D receptors, have yet to be clarified. The DCC assay remains the most practical method for the clinical evaluation of ER and PR status in samples from most postmenopausal women. Samples from premenopausal patients, or patients on tamoxifen therapy, should be evaluated by means of a suitable exchange assay, such as the hydroxylapatite method. Histochemical assays, while more rapid and convenient than the standard DCC or hydroxylapatite assay, have not been fully standardized and have not yet been proved to be a reliable alternative to more conventional techniques. However, they offer promise for a more convenient method of receptor evaluation in the future. The ER and PR status of a tumour, while not absolutely predictive, may serve as an aid in planning treatment for breast cancer patients. ER-negative patients do not benefit significantly from endocrine therapy, while approximately 50 per cent of patients with ER-positive tumours respond to hormonal manipulation. Hyposectomy and adrenalectomy are not largely historical therapies. Presently, endocrine therapies should be used selectively and with good judgement. Tamoxifen, other promising antioestrogens and aminoglutethemide given alone or in combination with other cemotherapeutic agents will play an increasing role in the therapy of breast cancer.