We all have been warned about the potential risk that hormone therapy (ADT) can cause to our heart and vascular health. A report from Lancet Oncology confirmed that men with prostate cancer living in Sweden when on hormonal therapies significantly increase their risk for experiencing a thromboembolic disease event.

The data used in this study was extensive, coming from the National Prostate Cancer Register of Sweden, which started in 1996 and includes 96% of all newly diagnosed cases of prostate cancer. The validation accuracy of this database is over 90%.

Men were treated for prostate cancer in accordance with the regional care guidelines. Those men who had endocrine therapy (ADT) mostly were treated with an LHRH agonist or had an orchiectomy, Anti-androgens were used as monotherapy in about 10% of the men in the database. The anti-androgens used were primarily non-steroidal, and for castration-resistant prostate cancer, estrogen and estramustine phosphate were most often prescribed.

The types of thromboembolic diseases (formation of a blood clot in a blood vessel or a thrombus that breaks loose and is carried by the blood stream to plug another vessel) experienced by the men were categorized as deep venous thrombosis (DVT), pulmonary embolism and arterial embolism, all very serious and potentially deadly. Standardized incident ratios (SIRs) were calculated, which are defined as the ratio of the observed number of a particular thromboembolic disease to the expected number of the thromboembolic disease.

From 1997 to 2007 the database identified 76,600 men diagnosed with PC of whom 30,642 received endocrine treatment. Of the men treated with endocrine therapies, 60.2% were aged 75 years or older and 14% had localized disease and a PSA <20ng/ml. The the total number of thromboembolic events was 1,881; 767 had a DVT, 873 a pulmonary embolism, and 241 arterial embolism. The SIRs for DVT, pulmonary embolism and arterial embolism were 1.90, 1.85, and 1.02, respectively.The risks for DVT and pulmonary embolism were increased regardless of whether patients received endocrine therapy, were treated with curative intent or were on surveillance. There was no increased risk for arterial embolism and a history of circulatory disease as a co morbid factor had no modifying effect on this.A larger SIR was noted for men younger than age 75 years and for those with metastatic disease. The SIRs for DVT were greater for men on endocrine treatment than for men who had undergone curative treatments or surveillance. The largest SIR was for men who had an orchiectomy and the lowest was seen for those treated with anti-androgens.For all treatment groups, the increased risks for thromboembolic events was greatly increased during the first 18 months after diagnosis, although the increased risk was still present after 4 years. Among men treated for curative intent, the first 6 months held the highest risk and this was greater for radical prostatectomy compared with radiotherapy.The largest absolute risks were for DVT and for men on endocrine treatment. The absolute risk increase after exposure to endocrine treatment was larger for those men younger than 74 years of age.Prostate cancer treatment clearly increases the risk for thromboembolic events, especially for men who use hormone therapy. Clearly, before deciding on what treatment to use a complete medical history and examination needs to be completed the results which need to be factored into the decision making around what treatments to use.Van Hemelrijck M, Adolfsson J, Garmo H, Bill-Axelson A, Bratt O, Ingelsson E, Lambe M, Stattin P, Holmberg L, Lancet Oncol. 2010 May;11(5):450-8 10.1016/S1470-2045(10)70038-3;PubMed Abstract PMID: 20395174Joel T Nowak, MA, MSW