First Year Of Androgen Deprivation Therapy Research Articles

Major adverse cardiovascular event risk following androgen deprivation therapy initiation by personal history of cardiovascular events.

351 Background: Associations between androgen deprivation therapy (ADT) and increased cardiovascular (CV) risk in prostate cancer (PCa) patients have been reported; however, how many of these major adverse CV events (MACE) are caused by ADT itself has been debated. One risk factor for increased CV risk is a prior history of CV events; an analysis found that each new CV event increased the probability of a future event. This study aims to evaluate the incidence of MACE after ADT initiation for patients with and without a prior medical history of MACE. Methods: Analyses of US electronic medical records (2010 to 2020) of PCa patients (n=45,059) receiving LHRH agonist and antagonist injections were conducted to evaluate MACE incidence after ADT initiation in patients with and without MACE history. Exclusion criteria included lack of ADT initiation date or myocardial infarction (MI)/stroke within 6 months prior to ADT initiation. MACE was defined as MI, stroke, and death from any cause. Kaplan-Meier event-free survival curves were constructed, and Cox regression was used to compare the MACE hazard rates between patients with and without a personal history of MACE. Multivariate Cox regression adjusted for agonists vs antagonist, increasing age per year, BMI (<18.5 vs ≥18.5 kg/m2), race (White vs Black), family MACE history, ethnicity (Hispanic vs non-Hispanic), urology vs oncology setting, history of hypertension, and history of hypercholesterolemia. Results: Overall, MACE incidence was 3.9% and 19.6% for the cohort at one year and four years after ADT initiation, respectively. MACE risk following ADT initiation was higher for patients with history of prior MACE (unadjusted: (HR=2.76, 95% CI [2.49, 3.06], p<0.001); adjusted: HR=2.29, 95% CI [1.93, 2.71], p<0.001). When MACE was divided into component events, the risks of myocardial infarction and stroke were higher for patients with a prior MACE history compared to those without (8 vs. 1% and 8 vs. 2%, respectively), and the risk of any-cause death was similar (13 vs. 14%). Conclusions: MACE incidence in PCa patients in the first year of ADT was consistent with previous publications.(3). When MACE risk was analyzed in detail, ADT patients with a personal history of stroke or myocardial infarction (MI) had a 4- and 8-fold greater risk of a subsequent stroke and MI, respectively, compared to those without a history of stroke or MI. Given the large sample size (~45,000 PCa patients) of this data set over the recent past decade, these results likely reasonably reflect the real world. Urologists and oncologists should work with cardiologists, cardio-oncologists, and primary care practitioners to ensure the highest quality CV care is delivered.

Cardiovascular Complications of Androgen Deprivation Therapy for Prostate Cancer.

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.

Long-term health care costs for prostate cancer patients on androgen deprivation therapy.

Comparing relative costs for androgen deprivation therapy (adt) protocols in prostate cancer (pca) requires an examination of all health care resources, not only those specific to pca. The objective of the present study was to use administrative data to estimate total health care costs in a population-based cohort of pca patients. Patients in Ontario with pca who started 90 days or more of adt at age 66 years or older during 1995-2005 were selected from cancer registry and health care administrative databases. We classified patients (n = 21,818) by regimen (medical castration, orchiectomy, anti-androgen monotherapy, medical castration with anti-androgen, orchiectomy with anti-androgen) and indication (neoadjuvant, adjuvant, metastatic disease, biochemical recurrence, primary nonmetastatic). Using nonparametric regression methods, with inverse probability weighting to adjust for censoring, and bootstrapping, we computed mean 1-year, 5-year, and 10-year longitudinal total direct medical costs (2009 Canadian dollars). Mean first-year costs were highest for metastatic disease, ranging from $24,400 for orchiectomy to $32,120 for anti-androgen monotherapy. Mean first-year costs for all other indications were less than $20,000. Mean 5-year and 10-year costs were lowest for neoadjuvant treatment: approximately $43,000 and $81,000 respectively, with differences of less than $4,000 between regimens. Annual costs were highest in the first year of adt. Orchiectomy was the least costly regimen for most time periods, but was limited to primary and metastatic indications. Outpatient drugs, including pharmacologic adt, accounted for 17%-65% of total first-year costs. Compared with combined therapies, the adt monotherapies, particularly orchiectomy when clinically feasible, are more economical. Our methods exemplified the use of algorithms to elucidate clinical information from administrative data. Our approach can be adapted for other cancers to expand the range of studies using Canadian administrative data.

Androgen-deprivation therapy-induced atherosclerosis in prostate cancer: Differences between GnRH-agonist and antagonist

Objectives: Cardiovascular disease (CVD) is one of the most common causes of mortality in prostate cancer patients. In prostate cancer treatment androgen deprivation therapy (ADT) is associated with weight gain and development of the metabolic syndrome. However, different modes of ADT can achieve castration. A post-hoc analysis of phase III trials suggests that GnRH-antagonists are associated with less cardiac events in men with pre-existing CVD during the first year of ADT. We investigated the effects of GnRH-agonist and GnRH-antagonist on the development of CVD in two mouse models.

Nadir testosterone within first year of androgen-deprivation therapy (ADT) predicts for time to castration-resistant progression: a secondary analysis of the PR-7 trial of intermittent versus continuous ADT.

Three small retrospective studies have suggested that patients undergoing continuous androgen deprivation (CAD) have superior survival and time to progression if lower castrate levels of testosterone (< 0.7 nmol/L) are achieved. Evidence from prospective large studies has been lacking. The PR-7 study randomly assigned patients experiencing biochemical failure after radiation therapy or surgery plus radiation therapy to CAD or intermittent androgen deprivation. The relationship between testosterone levels in the first year and cause-specific survival (CSS) and time to androgen-independent progression in men in the CAD arm was evaluated using Cox regression. There was a significant difference in CSS (P = .015) and time to hormone resistance (P = .02) among those who had first-year minimum nadir testosterone ≤ 0.7, > 0.7 to ≤ 1.7, and ≥ 1.7 nmol/L. Patients with first-year nadir testosterone consistently > 0.7 nmol/L had significantly higher risks of dying as a result of disease (0.7 to 1.7 nmol/L: hazard ratio [HR], 2.08; 95% CI, 1.28 to 3.38; > 1.7 nmol/L: HR, 2.93; 95% CI, 0.70 to 12.30) and developing hormone resistance (0.7 to 1.7 nmol/L: HR, 1.62; 95% CI, 1.20 to 2.18; ≥ 1.7 nmol/L: HR, 1.90; 95% CI, 0.77 to 4.70). Maximum testosterone ≥ 1.7 nmol/L predicted for a higher risk of dying as a result of disease (P = .02). Low nadir serum testosterone (ie, < 0.7 mmol/L) within the first year of androgen-deprivation therapy correlates with improved CSS and duration of response to androgen deprivation in men being treated for biochemical failure undergoing CAD.

Abstract 596: Androgen Deprivation Therapy--Induced Weight Gain and Atherosclerosis in Prostate Cancer: Differences Between Orchiectomy, GnRH Agonist and Antagonist

Cardiovascular disease (CVD) is one of the most common causes of mortality in prostate cancer patients. In prostate cancer treatment androgen deprivation therapy (ADT) is associated with weight gain and development of the metabolic syndrome. However, different modes of ADT can achieve castration. A post-hoc analysis of phase III trials suggests that GnRH antagonists are associated with less cardiac events in men with pre-existing CVD during the first year of ADT. We investigated the effects of bilateral orchiectomy, GnRH agonists and GnRH antagonists on the development of CVD in a mouse model. We hypothesize that GnRH antagonists will associate with reduced adiposity and development of atherosclerosis compared to GnRH analogues and orchiectomy. We used LDL receptor knockout mice (n=12/group) as models for CVD to investigate and compare the effects of orchiectomy, sham surgery, sham surgery plus GnRH antagonist (degarelix) and sham surgery plus GnRH agonist (leuprolide). Longitudinal weight gain (4 months), visceral fat accumulation (CT measurements), fasting blood glucose, glucose tolerance, serum triglycerides, and testosterone levels were studied along with characteristics of aortic atherosclerotic plaques. Leuprolide-treated mice gained significantly more weight and visceral fat compared to mice treated with degarelix. Significantly lower levels of serum triglycerides and better response to glucose loading were recorded in mice treated with degarelix. The atherosclerotic plaque area in the aortic sinus in leuprolide-treated and orchiectomized mice was significantly larger than in control mice, but not significantly different from control in degarelix-treated mice. The necrotic plaque area with degarelix was significantly smaller compared to leuprolide-treated and orchiectomized mice. In a preclinical mouse model, the use of GnRH antagonists attenuates weight gain and development of atherosclerosis.

Efficacy of docetaxel chemotherapy in metastatic prostate cancer (mPC) patients (pts) experiencing early castration resistance (CR).

5075 Background: mPC pts experiencing a short period of sensitivity to initial androgen deprivation therapy (ADT) have an unfavourable prognosis and lower probability of response to 2nd-line endocrine therapy suggestive of androgen receptor (AR) pathway-independent mechanisms of resistance. Recent studies have shown that docetaxel may kill PC cells through AR targeting. We thus investigated whether docetaxel may have efficacy in pts with early CR. Methods: Two independent prospective databases (Institut Gustave Roussy and Institut Jean Godinot) of mCRPC pts were analyzed. Early CR was defined as progression within the first year of ADT. The primary endpoint was time to progression (TTP) on docetaxel. Secondary criteria were clinical benefit (decrease in 2 points on a 0-to-10-pain-scale or in dose or type of pain medication), PSA response (decrease &gt; 50% in PSA serum level) and overall survival (OS). Pts with early CR were compared to pts with sensitivity to initial ADT &gt; 1 year (t-test for quantitative data, χ-2 test or Fischer’s exact test for qualitative data, Logrank test for TTP and OS). Results: 188 pts were selected for analysis. A higher frequency of unfavourable prognostic factors in pts with early CR as compared with others pts was observed with a median PSA serum level of 81 ng/dl (4-8000) vs 35 ng/dl (4-4260) (p=5.10-5), presence of visceral metastasis in 11% vs 2% of pts (p=0.01) and Gleason score ≥ 8 in 63% vs 41% of pts respectively (p=0.001). Clinical benefit and PSA response on docetaxel were observed in 84% vs 89% of pts (p=0.45) and 67% vs 81% of pts (p=0.10) respectively. Median TTP was 6.1 months (95%CI=6-7.5) vs 7.8 months (95%CI=7-8.3) (p=0.04). Median OS was 22.4 months (95%CI=17.1–28.6) vs 36.1 months (95%CI=26.3–42.4) (p=0.002). Conclusions: mPC pts experiencing early CR have more unfavourable baseline prognostic factors, shorter TTP on docetaxel and shorter OS as compared with pts experiencing time to CR &gt; 1 year. However, similar clinical and biological benefits from docetaxel chemotherapy were observed in this subset of pts. Since they have lower probability of response to second-line endocrine therapy, docetaxel appears as the best option after progression on initial ADT.

Structural Decay of Bone Microarchitecture in Men with Prostate Cancer Treated with Androgen Deprivation Therapy

Androgen deprivation therapy (ADT) used in the treatment of prostate cancer reduces bone mineral density (BMD) and predisposes to fractures. The structural basis of the BMD deficit and bone fragility is uncertain. We investigated changes in bone microarchitecture in 26 men (70.6±6.8 yr) with nonmetastatic prostate cancer during the first year of ADT using the new technique of high-resolution peripheral quantitative computed tomography. We conducted a 12-month prospective observational study in the setting of a tertiary referral center. After 12 months of ADT, total volumetric density decreased by 5.2±5.4% at the distal radius and 4.2±2.7% at the distal tibia (both P<0.001). This was due to a decrease in cortical volumetric BMD (by 11.3±8.6% for radius and 6.0±4.2% for tibia, all P<0.001) and trabecular density (by 3.5±6.0% for radius and 1.5±2.3% for tibia, all P<0.01), after correcting for trabecularization of cortical bone. Trabecular density decreased due to a decrease in trabecular number at both sites (P<0.05). Total testosterone, but not estradiol, levels were independently associated with total and corrected cortical volumetric BMD at the tibia. Sex steroid deficiency induced by ADT for prostate cancer results in microarchitectural decay. Bone fragility in these men may be more closely linked to testosterone than estradiol deficiency.

Androgen-deprivation-therapy-induced fractures in men with nonmetastatic prostate cancer: what do we really know?

Androgen deprivation therapy (ADT) alone or in combination with radiation therapy or other drugs is increasingly used for the treatment of localized, high-risk, or biochemical relapse of prostate cancer (PC). Bone mineral density (BMD) loss is rapid during the first year of ADT; up to 4.6% of total hip, femoral neck, and lumbar spine BMD loss has been reported in PC patients without bone metastases (nonmetastatic PC). In prospective studies, concurrent administration of a bisphosphonate or selective estrogen receptor modulator stabilized or increased BMD. Results of retrospective studies of ADT-treated patients who did not receive antiresorptive therapy have demonstrated a 21-37% increase in fracture risk. Because of the documented bone loss and increased fracture risk, patients should receive adequate counseling, monitoring, and therapy aimed at preventing or treating ADT-induced bone loss. Future studies should address the long-term impact of antiresorptive therapy on actual fracture rate and the impact on quality of life and healthcare costs.