The influence of treatment with estrogens and estramustine phosphate on platelet aggregation and plasma lipoproteins in non-disseminated prostatic carcinoma.

The treatment of prostatic carcinoma with estrogens is associated with an increased risk of cardiovascular as well as thromboembolic complications. In the present study, patients harboring highly or moderately differentiated prostatic carcinoma without signs of metastases were treated with either polyestradiolphosphate + etinylestradiol, estramustine phosphate or given no treatment. Subsequently, these patients were investigated regarding factors (platelet aggregation, plasma and platelet phospholipid composition and lipoprotein patterns) that might contribute to increased thrombogenesis and cardiovascular risk. The results indicate the presence of increased in vitro platelet aggregation in patients treated with polyestradiolphosphate + etinylestradiol compared to those treated with estramustine phosphate or given no treatment. A possible relationship between the availability of arachidonic acid in platelet membrane phospholipids and in vitro platelet aggregation is suggested. On the other hand the alterations in plasma lipoproteins observed during treatment are generally considered positive from an atherogenic point of view and do not seem relevant to the elevated incidence of cardiovascular disease in these patients.