Current practices of estrogen receptor determination

Questionnaires completed by 133 oncology investigators provided information about the use of estrogen receptor determination in breast cancer. All investigators reported measuring estrogen receptor levels in all primary breast cancers and often in metastatic cancers as well. Nearly half of these determinations are done in the institutions' own laboratories, and the rest elsewhere. Most commonly used in the dextran-coated charcoal procedure. Investigators generally classify assay results simply as positive or negative, using arbitrary levels for the decision. In one third of the institutions, this determination is used as the sole criterion for the use of hormonal therapy. A sharp difference of opinion exists regarding whether premenopausal cancer patients should castrated even if breast tumor receptor levels are negative.