Twenty patients with disseminated breast cancer unresponsive to conventional chemotherapy and chemohormonotherapy were treated with an alternating sequential schedule of ethinyl estradiol and medroxyprogesterone on the basis of correlations between hormones and estrogen and progestin receptors. Of 19 evaluable patients, six underwent partial or complete remission, while five others showed minor responses.
PIP: A pilot study was conducted on 20 patients with disseminated breast cancer previously unresponsive to conventional chemotherapy and chemohormonotherapy. The 20 women were treated with ethinyl estradiol orally on days 1 and 2, medroxyprogesterone on days 3-9. After a 2-day interval, the sequential cycle was repeated. 10% of the women had complete remission and 20% more had partial remissions. More than 1/4 had minor remissions and 10% had their disease stabilized. Side effects with the therapy were practically absent. The rationale for the sequential therapy was suggested by interactions among hormones and receptors and the priming activity of estrogens on progesterone receptors. These preliminary results indicate that an alternated sequential therapy of ethinyl estradiol and medroxyprogesterone may be useful in managing advanced cancer.