Diethylstilbestrol and Circulating Lipids in Women with Metastatic Breast Cancer: Lack of Dose Response over Three Log Units

Abstract

Thirty-five women with progressive metastatic breast cancer were treated in a double blind study with diethylstilbestrol in doses of 1.5, IS, ISO, or 1S00 mg daily. Plasma lipids and lipoproteins were measured serially in samples obtained from fasting patients. The pretreatment value for each variable was paired with the arithmetic mean of all values obtained during treatment. Plasma triglycerides increased 88% and plasma phospholipids rose 15% with therapy. There was no significant difference in mean responses of patients among the 4-dose levels, with increases apparent by 2 weeks of treatment, and stable as long as 2 yr. Plasma total cholesterol was unchanged with the estrogen therapy, although high-density liproprotein cholesterol increased. Serum immunoreactive insulin and plasma free fatty acids and glycerol did not change significantly. These data indicate that estrogen effects on circulating lipids accompanying pharmacologic doses of the hormone are independent of dosage. (/ Clin Endocrinol Metab 36: 381, 1973)