Prostate cancer and treatments increased risk for thromboembolic disease

Men with prostate cancer are at increased risk for thromboembolic disease when compared with men without prostate cancer — particularly those men assigned endocrine therapy, according to results from the Prostate Cancer Base Sweden database.

Researchers assessed the risk for thromboembolic disease in 76,600 men with prostate cancer assigned endocrine treatment (n=30,642), curative treatment (n=26,432) or surveillance (n=19,526).

Findings from this study were previously presented in September 2009 at the European Society for Medical Oncology's 34 Multidisciplinary Congress.

Data on age, serum concentrations of PSA, treatment at time of diagnosis, tumor grade and stage, socioeconomic status, thromboembolic disease history and mortality were pooled from the Prostate Cancer Base Sweden — a database including more than 96% of all newly diagnosed prostate cancers in Sweden.

Types of endocrine treatments received were categorized: anti-androgens (n=3,391), orchiectomy (n=5,340), gonadotropin-releasing hormone agonists (n=9,066), and gonadotropin-releasing hormone agonists in combination with long-term anti-androgens (n=11,646).

Of the 30,642 men who received endocrine therapy, 14% had a localized tumor and PSA concentrations less than 20 ng/mL vs. 66% of those assigned surveillance and 71.3% of those assigned curative treatment.

About 25% of men assigned anti-androgens had localized tumors; 19% had locally advanced disease and 19.8% had metastatic disease. Fifty-one percent of men assigned orchiectomy had metastatic disease when compared with 31.4% of men assigned gonadotropin-releasing hormone agonists.

Researchers identified 1,881 men who developed thromboembolic disease after prostate cancer diagnosis: 767 had deep vein thrombosis; 873 had a pulmonary embolism and 241 had an arterial embolism. The overall standardized incidence ratio for DVT was 1.9 (95% CI, 1.77-2.04); 1.85 for pulmonary embolism (95% CI, 1.73-1.97); and 1.02 for arterial embolism (95% CI, 0.89-1.15).

However, those men on endocrine therapy had the highest risk for DVT (SIR=2.48; 95% CI, 2.25-2.73) and pulmonary embolism (SIR=1.95; 95% CI, 1.81-2.15), but not for arterial embolism (SIR=1.0; 95% CI, 0.82-1.2). Similar patterns were seen in men assigned curative treatment and surveillance.

The highest risks for thromboembolic events across all treatment groups occurred during the first six months of treatment and were higher for radical prostatectomy than for radiotherapy.

In an accompanying editorial, Philip J. Saylor, MD,and Annemarie E. Fogerty, MD,both of the division of hematology-oncology at Massachusetts General Hospital Cancer Center in Boston, wrote that, “The data should increase clinical suspicion for venous thromboembolism in men with prostate cancer and stimulate further study of the potential interactions between androgen deprivation and blood coagulation.”

Van Hemelrijck M. Lancet Oncol. 2010;doi:10.1016/S1470-2045(10)70038-3.