A high pretreatment plasma oestradiol level is associated with a low risk of acute myocardial infarction in parenteral oestrogen therapy for locally advanced prostate cancer.

OBJECTIVE: To evaluate the relationship of pretreatment plasma oestradiol (ppE2) and testosterone (ppT) level to acute myocardial infarction (AMI) in patients with locally advanced prostate cancer primarily treated with parenteral polyoestradiol phosphate (PEP) or orchidectomy, considering the effect of age, performance status, pretreatment diseases and medication, and tumour stage and grade. PATIENTS AND METHODS: The present Finnprostate 6 study comprised 234 patients randomized to oestradiol or intramuscularly administered PEP (240 mg/month) therapy. Each patient was followed until the end of the primary therapy (up to 10 years) or until the first AMI (lethal or not). RESULTS: The risk of AMI, when the PEP and orchidectomy groups were analysed together, was lower in patients with a high ppE2 level, and this risk was independent of the ppT level, pretreatment diseases, medication, age, performance status, disease stage or grade. In the PEP therapy group the risk of AMI was statistically significantly lower in patients with a high ppE2 level (>or=93 pmol/L) than in those with a low ppE2 level (<93 pmol/L; risk ratio 0.28, 95% confidence interval 0.10-0.84, P = 0.022). There was no such difference in the orchidectomy group. The ppT level had no association with the risk of AMI. CONCLUSIONS: A high ppE2 level is associated with a low risk of AMI in patients with locally advanced prostate cancer treated with PEP; there was no such association for ppT level. In the orchidectomy group the ppE2 or ppT level was not statistically significantly associated with the risk of AMI.