According to research published in the Journal of the National Cancer Institute, the use of androgen deprivation therapy (ADT) in the treatment of localised prostate cancer in patients undergoing radical prostatectomy may increase the risk of death from cardiovascular causes.

The authors of this retrospective observational study note that ADT is increasingly being used in combination with local therapy to treat patients with high-risk localised prostate cancer. ADT has however been associated with an increased risk of certain adverse effects including diabetes and cardiovascular disease; the authors sought to investigate whether this could result in an increased cardiovascular mortality in such patients. They analysed data from patients with biopsy-proven prostate adenocarcinoma who were included in the Cancer of the Prostate Strategic Urologic Research Endeavor registry in the US. The study cohort consisted of 4892 patients with localised disease, who were treated with definitive local therapy (3632 with radical prostatectomy and 1630 with external beam radiation therapy, brachytherapy, or cryotherapy). A total of 1015 patients in the cohort received neo-adjuvant or adjuvant ADT treatment (i.e. gonadotropin-releasing hormone agonist [GNRHa] and/or an antiandrogen). Those treated with diethylstilboestrol, finasteride, chemotherapy, orchiectomy, or transurethral microwave therapy were excluded.

The primary endpoint was death from cardiovascular causes – this occurred in 131 patients in this study cohort. A competing risks regression analysis that controlled for age, presence of heart disease, and presence of diabetes was performed to assess whether the use of ADT at the time of initial therapy was associated with a shorter time to death from cardiovascular causes than non-use of ADT. The main findings for a median follow-up of 3.8 years were:

• In patients treated with radical prostatectomy, both ADT use (adjusted hazard ratio [HR] = 2.6; 95% CI 1.4 to 4.7; P = 0.002) and age (adjusted HR = 1.07; 95% CI 1.02 to 1.1; P = .003) were associated with increased risks of cardiovascular death

• For patients 65 years of age and older who underwent prostatectomy, the 5-year cumulative rates of cardiovascular death with and without ADT use were 5.5% (95% CI = 1.2% to 9.8%) and 2.0% (95% CI = 1.1% to 3.0%), respectively

• The use of ADT in patients treated with external beam radiation therapy, brachytherapy, or cryotherapy, was not associated with an increased risk of cardiovascular death (adjusted HR = 1.2; 95% CI 0.8 to 1.9; P = 0.4)
The authors state that “treatment with ADT can be beneficial in patients with unfavourable prostate cancer. However, clinicians should carefully weigh the potential risks and benefits of ADT, and consider a cardiovascular evaluation for their patients prior to initiating ADT." They advise that further prospective studies be carried out to confirm the association between ADT and cardiovascular mortality seen in this study.