The patient was receiving hormone treatment with a bone resorption inhibitor, zoledronic acid, a gonadotropin-releasing hormone agonist, goserelin acetate, and an estrogen agonist to treat castration-resistant prostate cancer with bone metastasis. There was a slight increase in the prostate-specific antigen (PSA) level, and ethinylestradiol (EE) was switched to estramustine phosphate sodium (EMP). Subsequently, the PSA level again increased, and the regimen was switched to enzalutamide. Thoracic pain suddenly occurred 2 weeks after EMP discontinuation. Under a tentative diagnosis of ischemic heart disease (IHD), the patient was admitted to the ward of the Department of Cardiology. In the left anterior descending branch, stenosis was observed. Percutaneous coronary intervention was performed. Estrogen agonists exhibit coagulation actions. On the product labeling of EE and EMP, myocardial infarction and angina are reported. In this patient, there had been no clinical findings suggesting ischemia, and there was no history of hypertension, diabetes mellitus, or dyslipidemia. The influence of estrogen-containing drugs must be considered even after discontinuation. Therefore, we considered that IHD was associated with EE or EMP in the present case. In addition, it was possible that the new antiandrogen drug enzalutamide caused IHD. It may be necessary to recognize that IHD may occur during the period of hormone treatment.
