Influence of treatment with diethylstilbestrol for carcinoma of prostate on platelet aggregation and plasma lipoproteins

Treatment of prostatic carcinoma with estrogens is accompanied by an increased risk for thromboembolic and cardiovascular complications. The underlying mechanisms are still unknown. Patients treated with diethylstilbestrol (DES) were compared with patients given no estrogen treatment regarding factors (platelet aggregation in vitro and plasma lipoproteins) that have been suggested to contribute to increased thrombogenesis and cardiovascular risk. The results do not show any increase in in vitro platelet aggregation in patients treated with DES compared with those given no treatment. This indicates that hyperaggregability does not contribute to the increased incidence in thromboembolic events seen in DES-treated patients. This is in contrast to the increased platelet aggregation previously described in patients treated with polyestradiolphosphate + etinylestradiol. The changes in plasma lipoproteins observed during DES-treatment are generally considered beneficial from an atherogenic point of view and do not appear to cause the elevated incidence of cardiovascular disease in these patients.