Cytotoxic estrogens in hormone receptive tumors

A high proportion of human mammary cancers contain a measurable amount of estrogen receptors. The presence of estrogen receptors correlates well with the response of patients to endocrine therapy, but not with their response to chemotherapy. However, receptor-mediated chemotherapy should result in more selective and efficient treatment of receptor-positive tumors. Several agents containing an estrogenic and a cytotoxic moiety have been synthesized in the past. It is not surprising that the affinity of these compounds for the estradiol receptor is very low, since most of them were synthesized before our knowledge of hormone receptor mechanisms. An international workshop on cytotoxic estrogens was held on September 27-28, 1979, in Diepenbeek, Belgium, to celebrate the opening of the Dr. L. Willems-Instituut. The purpose of the workshop was to determine the structural requirements for binding to the estrogen receptor and to obtain a consensus on screening techniques for selecting potential drugs of this type.