Weighing Risk of Cardiovascular Mortality Against Potential Benefit of Hormonal Therapy in Intermediate-Risk Prostate Cancer

Hormonal prostate cancer therapies and cardiovascular disease: a systematic review

Therapeutic intervention for prostate cancer mostly relies on eliminating circulating androgen or antagonizing its effect at the cellular level. As the use of endocrine therapies grows, an under-reported incidence of cardiovascular toxicities occurs in prostate cancer patients. In this review, we summarize data of clinical studies, investigating the cardiovascular and metabolic alterations associated with the use of old and new endocrine drugs (gonadotropin-releasing hormone [GnRH] agonists and antagonists, androgen receptor inhibitors, 17α-hydroxylase/c-17,20-lyase [CYP17] inhibitor) in prostate cancer. To date, studies looking for links between cardiovascular complications and hormone-mediated therapies in prostate cancer have reached conflicting results. Several confounding factors, such as age of patients and related cardiovascular liability, other comorbidities, and use of concomitant drugs, have to be carefully evaluated in future clinical trials. Further research is needed given the continuous advancements being made in prostate cancer treatment.

Cardiovascular and Metabolic Effects of Androgen-Deprivation Therapy for Prostate Cancer

Androgen-deprivation therapy (ADT) entails lowering serum testosterone levels to castrate levels and forms a cornerstone of the management of hormone-sensitive advanced prostate cancer; however, the benefit of ADT is partially offset by its detrimental metabolic and cardiovascular adverse effects. ADT decreases insulin sensitivity while promoting dyslipidemia and sarcopenic obesity, which leads to an increased risk of cardiovascular morbidity and potentially mortality. The risk seems to be highest in elderly patients who have had recent cardiovascular events before starting ADT. It is prudent to engage in an individualized risk-benefit discussion and develop a cohesive multidisciplinary management plan to medically optimize and closely observe these patients before and during treatment with ADT.

Impact of time to testosterone rebound and comorbidity on the risk of cause-specific mortality in men with unfavorable-risk prostate cancer

BACKGROUND

Herein, the authors evaluated how the time to testosterone rebound (TTR) after radiotherapy (RT) and 6 months of androgen deprivation therapy (ADT) impacted the risk of prostate cancer-specific mortality (PCSM) and cardiovascular-specific mortality (CVM) among men with varying comorbidity extent.

METHODS

Between 1995 and 2001, a total of 206 men who were randomized to receive RT either alone or with 6 months of ADT for unfavorable-risk PC and who had a comorbidity score assigned using the Adult Comorbidity Evaluation 27 metric comprised the study cohort. Multivariable competing risk regression was used to evaluate the impact of and possible interaction between comorbidity and TTR on PCSM and CVM.

RESULTS

After a median follow-up of 18.19 years, 30 men (18.6%), 39 men (24.2%), and 92 men (57.1%), respectively, had died of PC, CV disease, or other causes. As TTR increased, PCSM significantly decreased in men with no or minimal (adjusted hazard ratio [AHR], 0.53, 95% confidence interval [95% CI], 0.34-0.84 [P =.007]) and moderate to severe (AHR, 0.37; 95% CI, 0.14-0.99 [P = .048]) comorbidity. However, increasing TTR significantly increased the risk of CVM among men with moderate to severe comorbidity (AHR, 1.87; 95% CI, 1.40-2.49 [P <.001]), but not those with no or minimal comorbidity (AHR, 0.86; 95% CI, 0.57-1.29 [P =.46]), leading to a significant interaction between TTR and comorbidity (P = .001).

CONCLUSIONS

The results of the current study indicate that considering an intermittent course of ADT such that the TTR approaches 18 months, instead of continuous long-term administration of ADT, in men with moderate to severe comorbidity and high-risk PC may reduce the increased risk of CVM without increasing the risk of PCSM. Cancer 2018;124:1391-9. © 2018 American Cancer Society.

Cardiovascular Complications of Androgen Deprivation Therapy for Prostate Cancer

OPINION STATEMENT

Prostate cancer is a common hormone-sensitive malignancy, and androgen deprivation therapy (ADT) is a cornerstone of therapy in advanced disease. The most important and controversial of ADT side effects is cardiovascular (CV) toxicity. Prospective trials have demonstrated that ADT increases CV risk by lowering insulin sensitivity, causing dyslipidemia, and causing weight gain thus mimicking metabolic syndrome. Retrospective data suggests that ADT increases CV risk; however, data on cardiovascular mortality is equivocal. This discrepancy can be explained by study design limitations and selection bias inherent to post hoc analysis of trials not designed to study CV outcomes. Despite the adverse CV and metabolic sequelae of ADT, little data is available for optimal cardiac screening or management in these patients. The short-term CV risk is higher in patients who have had CV events in the year prior to starting ADT. A careful discussion of risk and benefit of ADT must take place with patients with pre-existing CV disease prior to initiating hormonal therapy. The duration of ADT must be considered. We recommend diligent pretherapy screening and optimization of cardiac risk factors and close surveillance especially within the first year of ADT.