Prospective determination of the hormonal response after cessation of luteinizing hormone-releasing hormone agonist treatment in patients with prostate cancer

Testosterone Recovery after Androgen Deprivation Therapy in Prostate Cancer: Building a Predictive Model

PURPOSE

To analyze the variability, associated actors, and the design of nomograms for individualized testosterone recovery after cessation of androgen deprivation therapy (ADT).

MATERIALS AND METHODS

A longitudinal study was carried out with 208 patients in the period 2003 to 2019. Castrated and normogonadic testosterone levels were defined as 0.5 and 3.5 ng/mL, respectively. The cumulative incidence curve described the recovery of testosterone. Univariate and multivariate analyzes were performed to predict testosterone recovery with candidate prognostic factors prostate-specific antigen at diagnosis, clinical stage, Gleason score from biopsy, age at cessation of ADT, duration of ADT, primary therapy and use of LHRH (luteinizing hormone-releasing hormone) agonists.

RESULTS

The median follow-up duration in the study was 80 months (interquartile range, 49-99 mo). Twenty-five percent and 81% of patients did not recover the castrate and normogonadic levels, respectively. Duration of ADT and age at ADT cessation were significant predictors of testosterone recovery. We built two nomograms for testosterone recovery at 12, 24, 36, and 60 months. The castration recovery model had good calibration. The C-index was 0.677, with area under the receiver operating characteristic curve (AUC-ROC) of 0.736, 0.783, 0.782, and 0.780 at 12, 24, 36, and 60 months, respectively. The normogonadic recovery model overestimated the higher values of probability of recovery. The Cindex was 0.683, with AUC values of 0.812, 0.711, 0.708 and 0.693 at 12, 24, 36, and 60 months, respectively.

CONCLUSIONS

Depending on the age of the patient and the length of treatment, clinicians may stop ADT and the castrated testosterone level will be maintained or, if the course of treatment has been short, we can estimate if it will return to normogonadic levels.

Enzalutamide in chemotherapy-naive patients with metastatic castration-resistant prostate cancer: A retrospective Korean multicenter study in a real-world setting

Purpose

This study aimed to evaluate the clinical efficacy of enzalutamide in chemotherapy-naïve metastatic castration-resistant prostate cancer (mCRPC) patients using real-world data from Korean patients.

Materials and Methods

We retrospectively reviewed the medical records of 199 chemotherapy-naïve patients with mCRPC at 13 tertiary centers in Korea between 2014 and 2017. All patients received enzalutamide daily and 89 patients received concurrent androgen deprivation therapy (ADT).

Results

The median age of the patients was 74 years. Initial results showed that 81.5% of the patients had Gleason score ≥8 and 33.3% of the patients had European Cooperative Oncology Group Performance Status 0. The overall mortality rate was 12%. The median OS was not archieved and 76.7% of patients were alive at 30 months. Median time until PSA progression was 6 months. The overall survival rate at 2 years was significantly higher (84.6% vs. 71.7%, p=0.015) and the duration of PSA progression-free survival was significantly longer (8.0 vs. 4.6 months, p=0.008) in patients receiving concurrent ADT than in those receiving enzalutamide alone. The incidence of adverse events of grade 3 or higher was 1.7%. Multivariate Cox proportional hazard analysis indicated that ADT administered concurrently with enzalutamide significantly improved the overall survival (hazard ratio, 0.346; 95% confidence interval, 0.125-0.958).

Conclusions

Enzalutamide is effective and safe for chemotherapy-naïve patients with mCRPC. Furthermore, the overall survival was significantly higher in patients receiving enzalutamide and concurrent ADT than in patients receiving enzalutamide alone.

Abiraterone acetate plus LHRH therapy versus abiraterone acetate while sparing LHRH therapy in patients with progressive, metastatic and chemotherapy-naïve, castration-resistant prostate cancer (SPARE): study protocol for a randomized controlled trial

Background

The value of continuation of luteinizing hormone-releasing hormone (LHRH) therapy in castration-resistant prostate cancer (CRPC) remains controversial and clear evidence is lacking. Argumentation for cessation of LHRH therapy is the prolonged suppression of testosterone levels after the withdrawal of LHRH analogues and the fact that disease progression occurs despite castration levels of testosterone. Especially upon treatment with the life-prolonging cytochrome P450 17-alpha-hydroxylase (Cyp17)-inhibitor, abiraterone, which has the ability to further suppress testosterone serum levels over LHRH therapy alone, continuation of LHRH therapy seems to be negligible. However, the proven increase of luteinizing hormone levels after LHRH withdrawal, which is even further increased by abiraterone, may counteract the effects of abiraterone by the induction of enzymes of steroidogenesis. Therefore, cessation of LHRH therapy when starting treatment with abiraterone in CRPC may display an unpredictable hazard to the patients. This study will explore the role of continuation of LHRH therapy when starting treatment with abiraterone in patients with asymptomatic or mildly symptomatic, chemotherapy-naïve CPRC.

Methods/design

The trial will assess radiographic progression-free survival after 12 months of treatment with abiraterone/prednisone in patients who will be randomized to receive continuing LHRH therapy versus LHRH withdrawal at the time of starting abiraterone therapy.

Discussion

This multicenter, prospective, randomized, exploratory phase-II trial will bring about new data regarding the efficacy and safety of abiraterone/prednisone treatment with or without continuation of LHRH therapy. In addition, further insight into the complex hormonal changes under treatment will be gained and the results of this trial may give rise to a larger phase-III trial to examine the possibility of withdrawing LHRH therapy in patients with CRPC.

Trial registration

ClinicalTrials.gov, ID: NCT02077634. Registered on 9 December 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2195-x) contains supplementary material, which is available to authorized users.

Hormonal response recovery after long-term androgen deprivation therapy in patients with prostate cancer

OBJECTIVE

The aim of this study was to evaluate hormonal recovery after cessation of androgen deprivation therapy (ADT) in a group of elderly prostate cancer patients.

MATERIALS AND METHODS

Forty patients with locally advanced or metastatic prostate cancer, with a mean age of 71.5 years [95% confidence interval (CI) 69.1-73.9], were treated with ADT for a mean duration of 74.6 months (95% CI 59.7-89.5 months). Mean follow-up time after ADT cessation was 36.5 months (95% CI 30.6-42.3 months). Serum testosterone and luteinizing hormone (LH) were determined at 6 month intervals after ADT cessation.

RESULTS

After 18 months of follow-up, all patients had recovered normal LH levels, while 38% of patients still presented castration levels of testosterone (< 50 ng/dl). A multivariate analysis was performed to find factors related to testosterone recovery (testosterone >50 ng/dl). Neither age at start of ADT nor clinical stage reached statistical significance. Only time under ADT was correlated with testosterone recovery (p = .031). Kaplan-Meier curves were obtained. Mean time for testosterone recovery was 14.5 months (95% CI 6.5-22.6 months) in patients treated with ADT for less than 60 months compared to 29.3 months (95% CI 19.6-39.1 months) in patients treated with ADT for more than 60 months (log-rank p = .029).

CONCLUSIONS

Age did not correlate with testosterone recovery in a group of elderly prostate cancer patients in whom ADT was stopped. Testosterone recovery after ADT cessation was significantly correlated with time under ADT treatment. Significant implications related to economic aspects of the dosage schedule may be considered.

Unrecognized kinetics of serum testosterone: impact on short-term androgen deprivation therapy for prostate cancer

PURPOSE

To evaluate the kinetics of serum testosterone (T) recovery following short-term androgen deprivation therapy (ADT), as the understanding thereof is essential for the proper management of prostate cancer (PCa), especially intermittent ADT.

MATERIALS AND METHODS

This prospective analysis included male sex offenders who voluntarily received leuprolide acetate in order to alleviate sexual aberrance. Thirty-three and 25 patients who received 3 and 6 months of ADT were assigned to Group A and Group B, respectively. Serum T levels were obtained every week during the on-cycle period, then monthly during the off-cycle period for at least 12 months.

RESULTS

The kinetics of serum T during the on-cycle period were similar in both groups. After flare reaction at week 2, a nadir of 0.45±0.29 ng/mL was achieved. In Group A, an abrupt rebound-upsurge was observed during the first 2 month off-cycle period, which surpassed the baseline level and reached a plateau level of 8.74±2.11 ng/mL during the flare (p<0.001). This upsurge was followed by a gradual decline back to baseline over the following 10 months. In Group B, a gradual increase was observed, and a baseline level of 7.26±1.73 ng/mL was reached at 5 months. Thereafter, an ongoing upsurge that surpassed baseline levels was observed until 12 months (8.81±1.92 ng/mL; p=0.002).

CONCLUSION

The kinetics of serum T recovery during the off-cycle period varied according to the duration of ADT. Serum T should be monitored beyond normalization, as an excessive rebound may improve quality-of-life, but hamper the treatment efficacy of PCa.

Androgen-deprivation therapy and risk for biliary disease in men with prostate cancer

BACKGROUND

Androgen-deprivation therapy (ADT) by either a gonadotropin-releasing hormone (GnRH) agonist or bilateral orchiectomy improves disease-related outcomes of men with prostate cancer but has a variety of adverse metabolic effects including obesity, increased abdominal girth, increased triglycerides, and insulin resistance. Each is a risk factor for gallstone disease. Additionally, GnRH agonist treatment was recently shown in metabolomic analyses to increase plasma levels of some bile acids.

OBJECTIVE

To assess the relationship between ADT and the incidence of biliary disease in men with prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We studied 183 842 men >65 yr of age living in Surveillance, Epidemiology, and End Results regions who were diagnosed with prostate cancer from 1992 to 2007 and followed through 2009.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We calculated incidence rates for biliary disease during treatment with GnRH agonists, orchiectomy, or no therapy. We used Cox proportional hazard models to assess the association of ADT with biliary disease.

RESULTS AND LIMITATIONS

Among 183 842 men with locoregional prostate cancer, 48.4% received GnRH agonist treatment and 2.2% underwent bilateral orchiectomy during follow-up. GnRH agonist treatment was associated with a significantly higher incidence of biliary disease compared with no treatment (15.7 vs 13.4 cases per 1000 person-years; p<0.001). In adjusted analyses, GnRH agonist use was associated with the risk of biliary disease (adjusted hazard ratio: 1.10; 95% confidence interval, 1.05-1.15; p<0.001). Orchiectomy was not significantly associated with biliary disease.

CONCLUSIONS

GnRH agonist treatment may be associated with a greater risk of incident biliary disease.

Diabetes and cardiovascular disease during androgen deprivation therapy: observational study of veterans with prostate cancer

Purpose

Androgen deprivation therapy with a gonadotropin-releasing hormone (GnRH) agonist is associated with increased fat mass and insulin resistance in men with prostate cancer, but the risk of obesity-related disease during treatment has not been well studied. We assessed whether androgen deprivation therapy is associated with an increased incidence of diabetes and cardiovascular disease.

Patients and Methods

Observational study of a population-based cohort of 73,196 fee-for-service Medicare enrollees age 66 years or older who were diagnosed with locoregional prostate cancer during 1992 to 1999 and observed through 2001. We used Cox proportional hazards models to assess whether treatment with GnRH agonists or orchiectomy was associated with diabetes, coronary heart disease, myocardial infarction, and sudden cardiac death.

Results

More than one third of men received a GnRH agonist during follow-up. GnRH agonist use was associated with increased risk of incident diabetes (adjusted hazard ratio [HR], 1.44; P < .001), coronary heart disease (adjusted HR, 1.16; P < .001), myocardial infarction (adjusted HR, 1.11; P = .03), and sudden cardiac death (adjusted HR, 1.16; P = .004). Men treated with orchiectomy were more likely to develop diabetes (adjusted HR, 1.34; P < .001) but not coronary heart disease, myocardial infarction, or sudden cardiac death (all P > .20).

Conclusion

GnRH agonist treatment for men with locoregional prostate cancer may be associated with an increased risk of incident diabetes and cardiovascular disease. The benefits of GnRH agonist treatment should be weighed against these potential risks. Additional research is needed to identify populations of men at highest risk of treatment-related complications and to develop strategies to prevent treatment-related diabetes and cardiovascular disease.

Biopsy Gleason score and the duration of testosterone suppression among men treated with external beam radiation and 6 months of combined androgen blockade

Study Type - Therapy (case series) Level of Evidence 4. What's known on the subject? and What does the study add? The return of testosterone to normal levels following short-course androgen blockade in prostate cancer is variable. Factors associated with a longer time to recovery include older age and lower baseline testosterone level. In this study, we found that among men treated with 6 months of combined androgen blockade and radiation therapy, higher biopsy Gleason grade was associated with a shorter time to testosterone normalization.

OBJECTIVE

• To determine whether the biopsy Gleason score is associated with duration of testosterone suppression following 6 months of combined androgen blockade (CAB) and radiation therapy (RT) in men with prostate cancer (PCa).

PATIENTS AND METHODS

• The study cohort consisted of 221 men with PCa treated with RT and 6 months of CAB between 1996 and 2005. • We defined the duration of testosterone suppression as the time between the last day of CAB and the date the testosterone returned to ≥ 252 ng/dL. We used Cox regression multivariable analysis to relate biopsy Gleason score to duration of testosterone suppression following cessation of CAB.

RESULTS

• A biopsy Gleason score of 8-10 had an adjusted hazard ratio (AHR) of 1.56 (95% confidence interval [CI] 1.04, 2.34; P= 0.03) for a shorter time to testosterone normalization relative to Gleason 6. Specifically, the 51 men with biopsy Gleason score of 8-10 had a median time to testosterone normalization of 17.0 months compared with 22.1 months and 23.8 months for those with biopsy Gleason ≤ 6 and 7, respectively. • Increasing age was significantly associated with a longer duration of testosterone suppression (AHR of 0.95 [95% CI 0.92, 0.97; P < 0.001]) as was a higher baseline PSA (AHR 0.82 [95% CI 0.69, 0.97; P= 0.02]).

CONCLUSION

• A biopsy Gleason score of 8-10 was associated with a shorter period of testosterone suppression following 6 months of CAB and RT. These data are consistent with the hypothesis that a factor released from high-grade PCa cells may impact on testosterone production.

Predominant suppression of follicle-stimulating hormone β-immunoreactivity after long-term treatment of intact and castrate adult male rats with the gonadotrophin-releasing hormone agonist deslorelin

Gonadotrophin-releasing hormone (GnRH) agonists are used to treat gonadal steroid-dependent disorders in humans and to contracept animals. These agonists are considered to work by desensitising gonadotrophs to GnRH, thereby suppressing follicle-stimulating hormone (FSH) and luteinising hormone (LH) secretion. It is not known whether changes occur in the cellular composition of the pituitary gland after chronic GnRH agonist exposure. Adult male Sprague-Dawley rats were treated with a sham, deslorelin, or deslorelin plus testosterone implant for 41.0 ± 0.6 days. In a second experiment, rats were castrated and treated with deslorelin and/or testosterone. Pituitary sections were labelled immunocytochemically for FSHβ and LHβ, or gonadotrophin α subunit (αGSU). Deslorelin suppressed testis weight by two-thirds and reduced plasma FSH and LH in intact rats. Deslorelin decreased the percentage of gonadotrophs, although the effect was specific to the FSHβ-immunoreactive (-ir) cells. Testosterone did not reverse the deslorelin-induced reduction in the overall gonadotroph population. However, in the presence of testosterone, the proportion of gonadotrophs that was FSHβ-ir increased in the remaining gonadotrophs. There was no effect of treatment on the total LHβ-ir cell population, although the loss of FSHβ in bi-hormonal cells increased the proportion of mono-hormonal LHβ-ir gonadotrophs. The castration-induced plasma LH and FSH increases were suppressed by deslorelin, testosterone or both. Castration increased both LH-ir and FSH-ir without increasing the overall gonadotroph population, thus increasing the proportion of bi-hormonal cells. Deslorelin suppressed these increases. Testosterone increased FSH-ir in deslorelin-treated castrate rats. Deslorelin did not affect αGSU immunoreactivity, suggesting that the gonadotroph population per se is not eliminated by deslorelin, although the ability of gonadotrophs to synthesise FSHβ is compromised. We hypothesise that the FSH dominant suppression may be central to the long-term contraceptive efficacy of deslorelin in the male.

Does comorbidity influence the risk of myocardial infarction or diabetes during androgen-deprivation therapy for prostate cancer?

BACKGROUND

Androgen-deprivation therapy (ADT) for prostate cancer (PCa) may be associated with cardiovascular disease and diabetes. Some data suggest that men with certain conditions may be more susceptible to developing cardiovascular disease than others.

OBJECTIVE

To assess whether the risk of myocardial infarction (MI) or diabetes during ADT is modified by specific baseline comorbidities.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a population-based observational study of 185 106 US men ≥66 yr of age diagnosed with local/regional PCa from 1992 to 2007. We assessed comorbidities monthly over the follow-up period.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional hazards models with time-varying variables assessing incident diabetes or MI.

RESULTS AND LIMITATIONS

A total of 49.9% of the men received ADT during follow-up. Among men with no comorbidities, ADT was associated with an increase in the adjusted hazard of MI (adjusted hazard ratio [AHR]: 1.09; 95% confidence interval [CI], 1.02-1.16) and diabetes (AHR: 1.33; 95% CI, 1.27-1.39). Risks of MI and diabetes were similarly increased among men with and without specific comorbid illnesses (p>0.10 for all interactions, with one exception). Previous MI, congestive heart failure, peripheral arterial disease, stroke, hypertension, chronic obstructive pulmonary disease, and renal disease were associated with new MI and diabetes, and obesity and rheumatologic disease were also associated with diabetes. Limitations include the observational study design, reliance on administrative data to ascertain outcomes, and lack of information on risk factors such as smoking and family history.

CONCLUSIONS

Traditional risk factors for MI and diabetes were also associated with developing these conditions during ADT but did not significantly modify the risk attributable to ADT. Strategies to screen and prevent diabetes and cardiovascular disease in men with PCa should be similar to the strategies recommended for the general population.

Androgens as therapy for androgen receptor-positive castration-resistant prostate cancer

Prostate cancer is the most frequently diagnosed non-cutaneous tumor of men in Western countries. While surgery is often successful for organ-confined prostate cancer, androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, this therapy is associated with several undesired side-effects, including increased risk of cardiovascular diseases. Shortening the period of androgen ablation therapy may benefit prostate cancer patients. Intermittent Androgen Deprivation therapy improves quality of life, reduces toxicity and medical costs, and delays disease progression in some patients. Cell culture and xenograft studies using androgen receptor (AR)-positive castration-resistant human prostate cancers cells (LNCaP, ARCaP, and PC-3 cells over-expressing AR) suggest that androgens may suppress the growth of AR-rich prostate cancer cells. Androgens cause growth inhibition and G1 cell cycle arrest in these cells by regulating c-Myc, Skp2, and p27Kip via AR. Higher dosages of testosterone cause greater growth inhibition of relapsed tumors. Manipulating androgen/AR signaling may therefore be a potential therapy for AR-positive advanced prostate cancer.

Individualized strategy for dosing luteinizing hormone-releasing hormone agonists for androgen-independent prostate cancer: identification of outcomes and costs

PURPOSE

Continuing androgen suppression is the current standard in men with androgen-independent prostate cancer (AIPC). An individualized strategy, wherein luteinizing hormone-releasing hormone agonists (LH-RHas) are redosed when serum testosterone approaches a non-castrate level, may decrease costs without worsening outcomes. To understand possible outcomes, we performed a cost-utility analysis comparing individualized and fixed LH-RHa dosing strategies in men with AIPC.

METHODS

The model used a societal perspective, a 5-year time horizon, and 3% annual cost discounting. The model accounted for direct costs of androgen suppression. Utilities were varied in accordance with published preference data.

RESULTS

Under base-case assumptions, individualized LH-RHa dosing yielded 1.089 expected quality-adjusted life years (QALYs), compared with 1.094 expected QALYs for fixed LH-RHa dosing. In cost analysis, lifetime per-patient costs for androgen suppression were estimated to be $5,694 for individualized LH-RHa dosing and $9,157 for fixed LH-RHa dosing. Applied to the total population, a strategy of individualized LH-RHa dosing would cost $170 million for androgen suppression, compared with $274 million for fixed LH-RHa dosing. Under these assumptions, adopting the individualized strategy resulted in $692,600 gained from a societal perspective for each QALY lost (the decremental cost utility).

CONCLUSION

The results suggest that an individualized LH-RHa dosing strategy would be associated with moderate savings on an individual basis but substantial savings on a population basis, and would not adversely affect quality of life or life expectancy. Further research is needed to establish the effects of this strategy on symptoms and survival, as well as patient satisfaction and true costs.

Histrelin: in advanced prostate cancer

Histrelin is a gonadotropin-releasing hormone agonist available in a diffusion-controlled reservoir drug delivery system for subcutaneous implantation. The subcutaneous histrelin implant provided sustained suppression of serum testosterone, luteinizing hormone (LH) and prostate-specific antigen levels for up to 1 year in patients with advanced prostate cancer in two phase II or III trials. In the noncomparative, multicentre, phase III study, serum testosterone was suppressed to castrate levels (i.e. < or =50 ng/dL) within 4 weeks in all patients who received a histrelin acetate 50 mg implant, with 99-100% of histrelin implant recipients maintaining castrate levels for the remainder of the 1-year treatment period. Such efficacy was provided irrespective of patient age or stage of disease. Although a transient surge in serum testosterone levels occurred after placement of the initial histrelin implant, no acute elevations in testosterone or LH levels were observed in patients whose implant was replaced after 1 year of therapy and suppression of these hormones continued to be maintained. The histrelin implant was generally well tolerated in patients with advanced prostate cancer in the phase III trial and in a pooled analysis. No patients prematurely discontinued treatment because of adverse events, most of which were the consequence of hormone suppression.

Androgen-Deprivation Therapy in Prostate Cancer: Clinical Evidence and Future Perspectives

Androgens are involved in the development and progression of prostate cancer even if the mechanism is not well-recognized. For this reason androgen-deprivation therapy remains a milestone for the treatment of patients with advanced and metastatic disease and, in the last years, in conjunction with radiotherapy and surgery in locally advanced tumors. Alternative options, such as intermittent deprivation suppression, seem to be promising in terms of clinical benefits and toxicity profile. However, current therapies present side effects, such as testosterone surge with consequent clinical flare-up, metabolic syndrome and hormone-resistance, which develops after a variable number of years. Novel therapies such as LH-RH antagonists and prolonged depot LH-RH analogues have been developed in order to avoid clinical flare-up and testosterone microsurges. Novel androgen synthesis inhibitors, such as abiraterone acetate and MDV3100, have been recently discovered and tested as promising hormonal second-line agents in patients with castration-resistant prostate cancer. Finally, long-term side effects from androgen deprivation, such as osteoporosis, sarcopenic obesity and cardiovascular morbidity should be carefully monitored and properly treated.

[Role of hormonotherapy in the treatment of metastatic prostate cancer]

Androgen privation is considered as the referent first line treatment for metastatic prostate cancer. Based on LHRH agonist, different therapeutic schedule included maximum androgenic blockage, intermittent treatment and associations with other drugs like oestrogen leading to possible hormonal manipulations. Since metastasis is confirmed, immediate treatment with continue LHRH agonist is the French Association of Urology (AFU) AFU recommendations treatment for metastatic prostate cancer but intermittent treatment can be considered as an option.

Testosterone recovery after prolonged androgen suppression in patients with prostate cancer

PURPOSE

We prospectively examined the extent and timing of testosterone recovery in patients with prostate cancer treated with 2 years of androgen suppression.

MATERIALS AND METHODS

A total of 153 patients with pT3N0M0 prostate cancer or positive margins after radical prostatectomy, or with prostate specific antigen relapse were treated with radiation to the prostate bed plus 2 years of androgen suppression as per a phase II study. Androgen suppression consisted of nilutamide for 4 weeks plus busereline acetate bimonthly for 2 years. Serum testosterone was measured at baseline, every 4 months during androgen suppression and every 6 months after androgen suppression during followup. Testosterone recovery to supracastrate levels, and to baseline and/or normal levels was estimated using Kaplan-Meier methods. Prognostic factors for testosterone recovery were examined.

RESULTS

A total of 121 patients who completed 2 years of androgen suppression and 20 patients who received shorter durations of androgen suppression (median 16 months) were available for testosterone recovery analysis. Median followup after finishing androgen suppression was 38.9 months. All patients achieved castrate levels on androgen suppression. At 36 months after completion of androgen suppression 93.2% and 71.5% had recovery to supracastrate (median time 12.7 months), and to baseline and/or normal testosterone levels (median time 22.3 months), respectively. On multivariate analysis younger age (younger than 60 years, p = 0.0006) and shorter androgen suppression duration (less than 2 years, p = 0.028) were prognostic for faster recovery to baseline and/or normal testosterone levels after adjusting for baseline testosterone levels (p = 0.447).

CONCLUSIONS

Testosterone recovery after prolonged androgen suppression is protracted. Older age and longer duration of androgen suppression result in significantly longer recovery times to baseline and/or normal testosterone levels.

Kinetics of serum androgen normalization and factors associated with testosterone reserve after limited androgen deprivation therapy for nonmetastatic prostate cancer

PURPOSE

Groups have investigated time to testosterone recovery in patients who have undergone androgen deprivation therapy, usually by measuring androgen every 3 months, with varying results. To our knowledge this represents the largest study using monthly testosterone and dihydroxytestosterone measurement to evaluate the kinetics of androgen recovery following limited androgen deprivation therapy.

MATERIALS AND METHODS

Monthly serum androgen levels were analyzed following 2, 6-month cycles of gonadotropin-releasing hormone agonist therapy as part of a randomized, placebo controlled study of the role of thalidomide in delaying time to prostate specific androgen progression.

RESULTS

By the Kaplan-Meier method the median time to testosterone normalization in cycles 1 vs 2 was 15.4 vs 18.3 weeks with similar dihydroxytestosterone recovery times. Neither on-study prostate specific antigen, Gleason score nor thalidomide treatment had a significant impact on time to testosterone normalization. However, in cycle 1 men with low baseline dihydroxytestosterone and those who were more than 67 years old had significantly longer time to T normalization on Cox model analysis. Additionally, in cycle 2 patients with prior local radiation therapy had longer time to testosterone normalization, although this was no longer significant on Cox model analysis. Cox model analysis in cycle 2 showed that low baseline dihydroxytestosterone and testosterone, low testosterone nadir and white race were associated with longer time to testosterone normalization.

CONCLUSIONS

Findings of delayed testosterone recovery may be useful for designing and analyzing clinical trials of limited androgen deprivation therapy and for estimating the duration of treatment associated side effects in patients undergoing limited androgen deprivation therapy.

Use of androgen deprivation therapy for metastatic prostate cancer in older men

OBJECTIVE

To assess factors associated with early or delayed androgen deprivation therapy (ADT) among men diagnosed with metastatic prostate cancer, and to assess the relationship between ADT and overall survival, as there is uncertainty about the ideal timing for initiating ADT in men with metastatic prostate cancer.

PATIENTS AND METHODS

We studied a population-based cohort of American men aged >or=66 years diagnosed with metastatic prostate cancer during 1992-2002 and followed to 2003. We assessed the receipt of ADT early (4 months), or not at all, using multinomial logistic regression to identify factors associated with treatment, and Cox proportional-hazard models to assess whether treatment was associated with survival.

RESULTS

Overall, 69.5% of men received early ADT and 7.3% delayed. Adjusted rates of early ADT were lower for black than white men (58.3% vs 71.0%), and of delayed ADT were higher for black than white men (12.7% vs 6.2%). Receipt of ADT was associated with improved survival (adjusted hazard ratio 0.69, 95% confidence interval 0.66-0.73). The benefit of early treatment did not differ from delayed treatment (P = 0.58).

CONCLUSIONS

A large minority of men with metastatic prostate cancer, particularly black men, receive delayed or no ADT. Early or delayed ADT was associated with similarly prolonged survival. After controlling for patient and tumour characteristics, survival did not differ by race, and receipt of ADT did not contribute to racial differences in survival.

[Time-course of plasma testosterone in patients with prostate cancer treated by endocrine therapy]

OBJECTIVE

To assess the time-course of plasma testosterone in patients with prostate cancer treated by endocrine therapy.

METHODS

A PubMed review of the literature on plasma testosterone and the various endocrine therapies for prostate cancer was performed.

RESULTS

The time-course of plasma testosterone varies according to the type of endocrine therapy. The effective castration level, classically considered to be 50 ng/dl, is currently tending to be replaced by 20 ng/dl. Following surgical castration, plasma testosterone reaches effective castration levels within several hours, while with LH-RH agonist therapy, plasma testosterone reaches its trough value after three to four weeks, and remains low for six months after stopping treatment. However, about 15% of patients treated with LH-RH agonists do not achieve effective castration levels. Plasma testosterone remains unchanged or even increases in response to anti-androgens. Plasma testosterone assay is of limited value in routine clinical practice in patients receiving endocrine therapy for prostate cancer, but should be performed in the case of elevation of PSA to ensure that the patient has achieved effective castration levels.

CONCLUSION

The correlation between plasma testosterone and progression of prostate cancer is unclear. Other studies are therefore necessary to define the value of plasma testosterone assay in patients treated for prostate cancer.

Pituitary expression of LHbeta- and FSHbeta-subunit mRNA, cellular distribution of LHbeta-subunit mRNA and LH and FSH synthesis during and after treatment with a gonadotrophin-releasing hormone agonist in heifers

The aim was to examine transcriptional and post-transcriptional regulation of LH and FSH biosynthesis. Female cattle were allocated to three groups: (i) Group 1, control (n = 6), synchronized to be at around Day 11 of the oestrous cycle on Day 31; (ii) Group 2 (n = 6), treated with gonadotrophin-releasing hormone (GnRH) agonist (deslorelin) for 31 days; and (iii) Group 3 (n = 6), treated with deslorelin for 28 days. All animals were slaughtered on Day 31. For animals in Group 2, pituitary content of LHbeta-subunit mRNA was suppressed 60% (P < 0.001) and LH 95% (P < 0.001), whereas FSHbeta-subunit mRNA was suppressed 25% (P > 0.05) and FSH 90% (P < 0.001). Three days after treatment with deslorelin (Group 3) LHbeta-subunit mRNA and LH remained suppressed (50% and 95%, respectively; P < 0.001). At the same time, FSHbeta-subunit mRNA did not differ from controls (P > 0.05) whereas FSH remained reduced by 80% (P < 0.001). The ratio of LHbeta-subunit mRNA present in the nucleus versus cytoplasm of gonadotroph cells was reduced (P < 0.05) in heifers during treatment with deslorelin (0.59 +/- 0.05) compared with the ratio in control heifers (1.31 +/- 0.22) and heifers 3 days after discontinuation of treatment (1.01 +/- 0.05). The findings indicated that treatment with GnRH agonist can suppress LHbeta-subunit mRNA expression without any significant effect on FSHbeta-subunit mRNA. As LH and FSH contents were suppressed to a greater degree than their beta-subunit mRNAs, it would appear that treatment with a GnRH agonist might influence gonadotrophin biosynthesis by a post-transcriptional mechanism(s). For LHbeta-subunit mRNA, this would appear not to be reduced export of message from the nucleus.

A randomized prospective trial evaluating testosterone, haemoglobin kinetics and quality of life, during and after 12 months of androgen deprivation after prostatectomy: results from the Postoperative Adjuvant Androgen Deprivation trial

OBJECTIVE

To assess testosterone and haemoglobin kinetics in the Postoperative Adjuvant Androgen Deprivation (PAAD) trial, and correlate these with quality of life (QoL) in this prospective randomized study.

PATIENTS AND METHODS

Forty-three patients met the criteria for high-risk cancer after RRP (Gleason score > or = 8, pT3c or Gleason score 7 concomitant with pT3a/b and positive surgical margins) and were prospectively randomized to either observation or AD for 12 months. Haemoglobin and testosterone levels were determined and QoL surveyed at regular intervals for 24 months.

RESULTS

Serum testosterone levels were castrate in 19 of 21 treated patients at 3 months and all at 6 months after starting AD. Levels failed to return to normal at 6 months after stopping treatment in six of 16 (38%) patients, and at 12 months in three of 17 (18%). AD caused a delay in the recovery of haemoglobin levels to normal after RRP. There was no statistically significant decline in the Short Form-36 QoL score with AD. Scores on the University of California-Los Angeles Sexual Functioning Scale were decreased during AD, but returned to a level not statistically significantly different from controls after stopping treatment.

CONCLUSION

A year of adjuvant AD after RRP affected serum haemoglobin, testosterone and sexual function reversibly, with return to control levels within the subsequent year in most patients. No significant effect on overall QoL with AD was detected in the study.

Individual variation of hormonal recovery after cessation of luteinizing hormone-releasing hormone agonist therapy in men receiving long-term medical castration therapy for prostate cancer

OBJECTIVE

To evaluate the process of hormonal recovery after cessation of luteinizing hormone-releasing hormone (LHRH) agonist treatment in patients who had received long-term LHRH agonist therapy for prostate cancer.

MATERIAL AND METHODS

Men who had successfully undergone androgen deprivation therapy with only monthly LHRH agonist therapy for > 30 months were enrolled and the administration of LHRH agonist was discontinued. Serum total testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prostate-specific antigen (PSA) were measured before the cessation of LHRH agonist therapy and every 4 weeks thereafter, and the administration of LHRH agonist remained suspended until the total testosterone level recovered to > 50 ng/dl.

RESULTS

Ten patients were enrolled in the study. The median (range) castration period and the levels of serum LH, FSH, total testosterone and PSA at cessation of therapy were 39 (30-56) months,<0.5 (<0.5-1.8) mIU/ml, 6.4 (3.0-15.9) mIU/ml, 15.3 (5.8-34.7) ng/dl and 0.13 (0.02-0.89) ng/ml, respectively. Testosterone recovered to > 50 ng/dl in all cases. There were large variations in the times required for recovery of LH and FSH (30-100 days) and serum testosterone (30-330 days). PSA began to increase at various testosterone levels, and there was a large variation (0-83%; median 41%) in the ratio of the androgen suppression (testosterone < 50 ng/dl) time to the period of LHRH agonist cessation.

CONCLUSIONS

There was considerable variation in the hypothalamus-pituitary-testicular hormone profiles during recovery from long-term medical castration. These findings are noteworthy when interruption of androgen deprivation therapy is applied with the intention of delaying the progression of hormone-refractory cancer or improving the patient's quality of life.

Failure to Maintain a Suppressed Level of Serum Testosterone during Long-Acting Depot Luteinizing Hormone-Releasing Hormone Agonist Therapy in Patients with Advanced Prostate Cancer

OBJECTIVES

It was the aim of this study to analyze the failure rates in achieving or maintaining castrate levels of serum testosterone in patients with advanced prostate cancer treated with the 3-month luteinizing hormone-releasing hormone agonist (LH-RH) therapy.

METHODS

Total serum testosterone was determined in 234 patients with prostate cancer in a cross-sectional study. A subset of 90 patients submitted to radical prostatectomy was used as the control group (group 1), and 144 patients with advanced prostate cancer under androgen suppression therapy were included in the study group (groups 2 and 3). The study group was divided into 93 patients (group 2) treated with 50 mg daily bicalutamide and LH-RH agonist (maximal androgen blockade, MAB) and 51 patients treated with the LH-RH agonist alone (group 3). Median follow-up after androgen suppression was 42 months. The castrate testosterone level was defined below 50 ng/dl.

RESULTS

The mean serum testosterone level was 29.1 ng/dl in patients undergoing MAB (group 2) and 29.5 ng/dl in patients treated with the LH-RH agonist (group 3; p > 0.05). In group 1, the mean serum testosterone was 445.2 ng/dl (p < 0.0001). The rate of patients with a serum testosterone level higher than 50 ng/dl was 10.9% in patients undergoing androgen suppression, 10% in patients with MAB treatment and 12.5% in those with LH-RH agonist therapy (p > 0.05). In group 1, 98.9% of the patients had a serum testosterone level higher than 50 ng/dl.

CONCLUSIONS

A small but clinically significant rate of patients under 3-month LH-RH agonist therapy fail to achieve or maintain castrate testosterone serum levels. This finding supports the need of monitoring testicular response during LH-RH agonist therapy.

Intermittent androgen deprivation: clinical experience and practical applications

Prostate cancer is more frequently being diagnosed at an earlier age, men are dying of prostate cancer at an older age, and men are now treated with androgen deprivation for biochemical relapse. As a result, the amount of time that patients are potentially subjected to androgen deprivation is increasing. Intermittent androgen deprivation (IAD) has been investigated as a potential alternative to continuous androgen deprivation (CAD) in order to improve quality of life and potentially delay the progression to androgen independence. Along with the increased use of primary hormonal therapy in clinically localized prostate cancer, IAD may supplant the traditional surgical or radiotherapy options, specifically in men who have underlying co-morbidities and decreased life expectancy. There are ongoing multi-institutional, randomized trials that will lend insight into the utility, efficacy, and feasibility of IAD versus CAD. This article discusses the theoretical benefits and rationale of IAD and reviews the completed and on-going IAD trials. Finally, the controversies, practical applications, and future directions of IAD are addressed.

Testosterone and erectile function recovery after radiotherapy and long-term androgen deprivation with luteinizing hormone-releasing hormone agonists

OBJECTIVE

To study the recovery of testosterone levels and erectile function in men who received radiotherapy plus long-term adjuvant androgen deprivation (LTAD) with luteinizing hormone-releasing hormone (LHRH) agonists.

PATIENTS AND METHODS

From April 2000 to July 2001, men who had completed prostate radiotherapy with > or = 2 years of LTAD, and had their last LHRH agonist injection at least 6 months before, were invited to participate. At study entry, the men completed the International Index of Erectile Function (IIEF), and their serum total testosterone (TT), prostate-specific antigen, LH, follicle-stimulating hormone, haemoglobin, and body mass were measured. This assessment was repeated at 1 year.

RESULTS

In all, 20 men were recruited, with a mean (range) age of 70 (55-81) years. Defining a normal TT level as > or = 8.0 nmol/L, the median time to a normal level was 2.3 years (95% confidence interval (CI), 1.9-4.2). The median duration of castrate TT levels was 8 months (95% CI, 6.2-14.9). LH recovered before TT, suggesting that the rate-limiting step in the recovery of TT may be at the testicular level. The median time to recovery of normal LH levels was 3.8 months, compared to 8.0 months to reach supracastrate TT levels, and 2.3 years to reach normal TT levels. Age and the LH/TT ratio were associated with the time to recovery of both supracastrate and normal levels of TT. The IIEF was completed by 17 men; there were no significant changes in the scores in any domain of the IIEF during the study.

CONCLUSIONS

Most men recover supracastrate testosterone levels after LTAD and external beam radiotherapy, but recovery of 'normal' testosterone levels is slow. Few men recover potency and sexual desire. The patients age and LH/TT ratio may be predictive of the time to recovery of both supracastrate and normal testosterone levels.

Time course of serum testosterone and luteinizing hormone levels after cessation of long-term luteinizing hormone-releasing hormone agonist treatment in patients with prostate cancer

INTRODUCTION

In order to elucidate the influence of hormone-releasing hormone (LH-RH) agonist therapy cessation on pituitary/testicular function and its clinical implications, we investigated prospectively hormonal (luteinizing hormone: LH; testosterone: T) responses in patients with prostate cancer who received long-term LH-RH 10 agonist therapy.

PATIENTS AND METHODS

A consecutive 32 patients who had received LH-RH agonist therapy over 24 months were enrolled. As a baseline, T and LH were measured at the time of LH-RH agonist therapy cessation, monthly for 3 months, and subsequently, every 3 months.

RESULTS

The median duration of LH-RH agonist therapy was 30 months (24-87 months) with median follow-up duration of 24 months following cessation. All patients had castrated T levels and suppressed LH levels at baseline. Median duration of castrated T levels following cessation was 6 months. Median time to normalization of T levels was 24 months. LH levels returned to normal within 3 months in all cases. Patients who received androgen deprivation therapy for 30 months or longer required a longer time for recovery of T levels. Patients over 65 years of age showed a statistically significant longer time for recovery of T levels (P=0.0167).

CONCLUSIONS

Long-term LH-RH agonist therapy has remarkable effects on serum T level that last for a significant time after cessation, a fact that should be applied to the interpretation of both PSA and serum T levels after cessation of androgen deprivation therapy.

Intermittent Androgen Castration: A Biological Reality during Intermittent Treatment in Metastatic Prostate Cancer?

INTRODUCTION

To assess the effects of intermittent maximal androgen blockade (IMAB) on testosterone (T) levels during on- and off-treatment periods.

MATERIALS AND METHODS

A total of 51 patients with metastatic prostate cancer underwent a 6-months period of continuous maximal androgen blockade (MAB) consisting of leuprorelin (3.75 mg at monthly intervals) plus flutamide (250 mg t.i.d.) followed by IMAB. During each cycle, the cut-off prostate-specific antigen (PSA) levels to stop and resume treatment were 4 and 10 ng/ml, respectively. IMAB continued until progression under treatment occurred. Monthly PSA and T measurements were performed in central laboratories.

RESULTS

From the 51 patients included (mean age 67.6 years), 27, 16, 12, 8 and 5 underwent a second, third, fourth, fifth and sixth cycle, respectively (mean follow up: 17 months). Before treatment, 4 patients had a T lower than normal laboratory value but these recovered all to a normal T value at the end of the first cycle. During the 6 cycles, only 8 patients did not recover a normal T at least once during the off-treatment periods (OTP). The mean T values at the end of each OTP did not change during these 6 cycles (Anova test, p=0.621) with a mean stable recovery delay of 32-43 days (Anova test, p=0.722).

CONCLUSION

IMAB protocol with an initial 6-month treatment period can result in an intermittent castration with the recovery of normal T levels in most patients during six consecutive cycles of treatment.

A PROSPECTIVE ANALYSIS OF THE TIME TO NORMALIZATION OF SERUM ANDROGENS FOLLOWING 6 MONTHS OF ANDROGEN DEPRIVATION THERAPY IN PATIENTS ON A RANDOMIZED PHASE III CLINICAL TRIAL USING LIMITED HORMONAL THERAPY

PURPOSE

Patients with prostate cancer are treated with neoadjuvant, adjuvant and intermittent therapy with gonadotropin-releasing hormone agonists (GnRH-A). While these are largely successful in decreasing testosterone (T) and dihydroxytestosterone (DHT) to castrate levels, discontinuation of such therapy often results in continued suppression of androgens for variable periods of time. We present the largest published series of patients evaluating the timing of T and DHT increase after cessation of GnRH therapy.

MATERIALS AND METHODS

Serial T and DHT measurements were prospectively obtained every 3 months while on GnRH-A then monthly upon discontinuation of GnRH-A. Analysis of time from the second 3-month GnRH-A administration to T and DHT increase was undertaken.

RESULTS

A total of 80 evaluable patients had a median time to T 50 ng/dl or greater of 12.9 weeks and a median time to T normalization (212 ng/dl or greater) of 16.6 weeks. Low baseline T was associated with a prolonged time to T 212 ng/dl or greater (p = 0.0086) and a similar trend was seen in patients older than 66 years (p = 0.08). There were 62 evaluable patients with a median of 14.9 weeks to DHT 150 pg/ml or greater. There was no association with Gleason score at diagnosis, on study prostate specific antigen, type of prior definitive therapy, or any prior hormonal therapy and time to increase in circulating androgens.

CONCLUSIONS

After 6 months of GnRH-A therapy in these patients, DHT and T levels did not return to normal for a median of 14.9 and 16.6 weeks, respectively.

Testosterone recovery and changes in bone mineral density after stopping long-term luteinizing hormone-releasing hormone analogue therapy in osteoporotic patients with prostate cancer

OBJECTIVE

To investigate the rate of testosterone recovery and changes in bone mineral density in patients found to be osteoporotic while receiving luteinizing hormone-releasing hormone (LHRH) analogues after changing to antiandrogen monotherapy in an attempt to reduce further demineralization.

PATIENTS AND METHODS

Fifteen patients receiving LHRH analogue therapy for > or = 1 year were identified as osteoporotic by distal forearm dual X-ray densitometry. They were then converted to antiandrogen monotherapy, and prostate specific-antigen (PSA) and total testosterone monitored at 3-monthly intervals. The forearm densitometry was repeated at 1 year.

RESULTS

All patients had some testosterone recovery; the mean (range) duration to initial detectable testosterone was 12.8 (6-22) months. Six patients had a normal testosterone level after a mean of 17.5 (14-30) months. In the year after stopping LHRH analogue therapy the mean bone mineral density (t-score) decreased by 7.2%.

CONCLUSIONS

Osteoporotic patients, after stopping LHRH analogues, continue to have suppressed levels of testosterone which have a detrimental effect on bone mineral density. We therefore would not advocate conversion to antiandrogen monotherapy to improve bone density, and suggest alternative therapeutic intervention e.g. bisphosphonate therapy, for these patients.

REVERSIBILITY OF ANDROGEN DEPRIVATION THERAPY IN PATIENTS WITH PROSTATE CANCER

PURPOSE

We determined the duration of testosterone suppression and recovery in patients with prostate cancer treated with a hydrogel implant releasing the gonadotropin releasing hormone (GnRH) agonist histrelin or treated with a depot GnRH agonist.

MATERIALS AND METHODS

Luteinizing hormone (LH) and testosterone (T) responses were monitored in 3 groups. Group 1 comprised 7 patients treated with histrelin implant, which is inserted into the arm of the patient while under local anesthesia, and suppresses LH and testosterone. Following implant removal antiandrogens (flutamide or bicalutamide) were administered. Group 2 comprised 8 patients treated with long-term depot GnRH super agonists which were later withheld and patients were given bicalutamide. Group 3 consisted of 7 patients treated with bicalutamide.

RESULTS

In group 1 LH and T were in the castration range while implants were in place. LH increased 1 to 6 weeks after implant removal followed by an increase in T. In 7 of 8 patients in group 2, LH, T and prostate specific antigen remained suppressed for 9 months. In 6 of 7 group 3 patients LH and T increased with a decrease in prostate specific antigen.

CONCLUSIONS

Despite continuous prolonged T suppression for up to 3 years due to histrelin implant, LH and T increased rapidly following implant removal, indicating that suppression is reversible. In view of the 9-month suppression of LH and T after the last depot GnRH injection in 7 of 8 patients, it is possible to space GnRH agonist administration at longer intervals. However, T must be monitored to determine that suppression is maintained.

Androgen deprivation therapy for prostate cancer: current status and future prospects

Androgens play a major role in promoting the development and progression of prostate cancer. As a result, androgen ablation or blockade of androgen action through the androgen receptor (AR) has been the cornerstone of treatment of advanced prostate cancer. Different strategies involving this hormonal therapy produce a significant clinical response in most of the patients, but most responders eventually lose dependency, resulting in mortality. Thus, whether hormonal therapy contributes to the improvement of overall survival rates, especially in patients with advanced prostate cancer, remains controversial. However, patients with advanced disease clearly have a benefit from androgen deprivation-based treatment for palliating their symptoms and for improving the quality of their lives. In order to improve overall survival, novel treatment strategies that prolong the androgen-dependent state and that are useful for androgen-independent disease based on specific molecular mechanisms need to be identified.

American Society of Clinical Oncology recommendations for the initial hormonal management of androgen-sensitive metastatic, recurrent, or progressive prostate cancer

PURPOSE

To develop a clinical practice guideline for the management of men with metastatic, recurrent, or progressive carcinoma of the prostate. The focus of this document is on the use, combinations, and timing of various forms of androgen deprivation therapy (ADT) for the palliation of men with androgen-sensitive disease.

METHODS

An expert panel and writing committee were formed. The questions to be addressed by the guideline were determined, and a systematic review of the literature was performed, which included a search of online databases, bibliographic review, and consultation with content experts. A priori criteria were used to select studies for analysis and study authors were contacted when necessary.

RESULTS

There were 10 randomized controlled trials, six systematic reviews, and one Markov model available to inform the guidelines.

CONCLUSION

A full discussion between practitioner and patient should occur to determine which therapy is best for the patient. Bilateral orchiectomy or luteinizing hormone releasing hormone agonists are the recommended initial treatments. Nonsteroidal antiandrogen therapy may be discussed as an alternative, but steroidal antiandrogens should not be offered as monotherapy. Patients willing to accept the increased toxicity of combined androgen blockage for a small benefit in survival should be offered nonsteroidal antiandrogen in addition to castrate therapy. Until data from studies using modern medical diagnostic/biochemical tests and standardized follow-up schedules become available, no specific recommendations can be issued regarding the question of early versus deferred ADT. A discussion about the pros and cons of early versus deferred ADT should occur.

Changes in prostate-specific antigen and hormone levels following withdrawal of prolonged androgen ablation for prostate cancer

We conducted a study in order to characterize changes after withdrawal of androgen ablation (AA) for prostate cancer. AA was withdrawn in 38 Japanese patients with prostate cancer who had undergone this therapy for various periods. Patients were stratified into those who had undergone AA for less than 24 months (Group 1, n=12) and those with longer periods of AA (Group 2, n=26). Serial changes in hormones and prostate-specific antigen (PSA) were prospectively monitored following cessation of AA. The median durations of AA in the two groups were 8.5 and 54.5 months, respectively. Levels of total testosterone (T), luteinizing hormone and PSA increased significantly with time. At the end of 2 y, 30/38 patients (78.9%) had T levels above 50 ng/dl and 19/38 (50%) had levels above 320 ng/dl. Patients in Group 2 required significantly longer duration for T recovery. Complete T recovery is not always accompanied by rising PSA. Recovery of T levels is often slow following cessation of prolonged AA. Expression of PSA after AA is often variable and unpredictable. Thus, interpretation of outcomes in clinical trials incorporating AA needs caution and careful consideration.

Hormonal therapy for patients with advanced adenocarcinoma of the prostate: is there a role for discontinuing treatment after prolonged androgen suppression?

OBJECTIVES

To determine the hormonal (luteinizing hormone [LH], testosterone) and biochemical (prostate-specific antigen [PSA]) response to withdrawal of LH-releasing hormone (LHRH) agonist therapy for patients with prostate cancer with an undetectable PSA who received this treatment for an extended period.

METHODS

Four selected patients older than 70 years of age with advanced adenocarcinoma of the prostate who were treated with a depot injection of LHRH and antiandrogen therapy had their treatment discontinued. During the period of total androgen blockade, each patient obtained and maintained a persistent undetectable PSA level. After cessation of androgen blockade, patients underwent serum measurements of PSA and testosterone at baseline and then every 6 months for 36 months. Serum LH was performed at baseline and then at 6, 18, and 36 months.

RESULTS

At the time androgen ablative therapy was discontinued, patients had received LHRH agonist/antiandrogen therapy for a mean of 108 months (range 94 to 120). All 4 patients had castrate levels of testosterone (less than 0.5 ng/mL) and undetectable levels of PSA at baseline and with continued monitoring. At 6 and 18 months, all patients except one had LH levels in the normal range. All 4 patients remained clinically asymptomatic throughout the follow-up period with undetectable PSA levels.

CONCLUSIONS

Withdrawing hormonal therapy in asymptomatic patients with advanced prostate cancer after prolonged total androgen blockade was noted to be safe and effective in elderly patients who had achieved an undetectable PSA level. It appears that reduced testosterone levels may be a result of altered and potentially irreversible Leydig cell function rather than continued suppression of the hypothalamic-pituitary-testicular axis.

Intermittent androgen suppression in patients with prostate cancer

OBJECTIVES

To evaluate intermittent androgen suppression (IAS) in patients with prostate cancer and to try to define predictive factors for biochemical progression.

PATIENTS AND METHODS

From 1989 to 2001, 146 patients received IAS as a primary treatment for localized, advanced or metastatic prostate cancer (72 men) or as a treatment for prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP) and/or radiation therapy (74 men). Androgen-deprivation treatment (ADT) was continued up to 6 months after PSA became undetectable or a nadir PSA level was reached. ADT was then re-instituted when the PSA level was> 4 ng/mL for patients who had RP or> 10 ng/mL for the others.

RESULTS

After a mean (range) follow-up of 45.6 (12-196.9) months, 24 patients had biochemical progression. These patients were younger than those with no biochemical progression (67 vs 72 years, P = 0.004) and had a statistically higher Gleason score (7.21 vs 6.52, P = 0.01) and PSA level (111.1 vs 32.1 ng/mL, P = 0.05), and a shorter first phase without treatment (7.6 vs 11.2 months, P = 0.05). Overall 5-year metastatic disease free survival of 91.3%. The overall 5-year biochemical recurrence-free survival was 68%. Using multivariate analysis, a Gleason score of >or= 8 (P = 0.021), first-phase duration with no treatment of < 1 year (P = 0.044), positive lymph nodes or metastatic disease at the time of starting IAS (P = 0.023) and age < 70 years (P = 0.037) were the strongest predictors of biochemical progression.

CONCLUSION

IAS appeared to be a feasible treatment; the best candidates being those aged> 70 years with localized prostate cancer and a Gleason score of <or= 7.

Testosterone recovery following prolonged adjuvant androgen ablation for prostate carcinoma

BACKGROUND

This study was conducted to describe the rate and completeness of the recovery of testosterone production following prolonged temporary androgen ablative therapy in men with prostate carcinoma undergoing curative radiation therapy.

METHODS

Two-hundred and sixty-seven men treated with between 3 months and 3 years of adjuvant androgen ablation (AA) were followed at 6-month intervals following cessation of their androgen deprivation therapy. A comparative group of 518 men not undergoing AA were also followed.

RESULTS

Drugs used included low dose cyproterone/stilboestrol (CPA/DES) in combination (56%) and 1 month depot (18%) and 3 month depot (25%) leutinizing hormone releasing hormone agonist (LHRHa). Seventy-nine percent of men in the current study recovered normal testosterone levels (10nmol/L), and 93% recovered levels of at least 5nmol/L. In comparison, men who had never received androgen ablative therapy showed a fall of testosterone, with 17% having sub-normal levels after 3 years. Median time to testosterone recovery was 10 months. Factors associated on multivariate analysis with delayed testosterone recovery included advanced age (P = 0.008), low pre-therapy testosterone (P = 0.04), and the use of 3 month LHRHa preparations as compared with CPA/DES (P = 0.002) or 1 month LHRHa preparations (P = 0.015). The duration of drug use was not significantly associated with time to testosterone recovery.

CONCLUSIONS

Long-acting LHRHa preparations appear to have a more prolonged action than previously supposed. Most men treated for up to 2 years recover normal testosterone levels after cessation of adjuvant androgen ablation, and the limited data available in the current study on patients treated for 3 years also suggests most will recover.

Effective long-term androgen suppression in men with prostate cancer using a hydrogel implant with the GnRH agonist histrelin

OBJECTIVES

To evaluate the effectiveness of a hydrogel implant containing the gonadotropin-releasing hormone (GnRH) agonist histrelin in suppressing testosterone production in men with prostate cancer and to determine the effective dose (one, two, or four implants).

METHODS

Forty-two men with prostate cancer and indications for androgen ablation were treated with one, two, or four implants. In two of the clinics, comprising 27 subjects, the treatment period was 12 months, with replacement with the same number of implants at 12-month intervals. In a third clinic, which treated 15 subjects, the implants were left in place for up to 30 months. The total experience was 605 treatment months.

RESULTS

The histrelin levels were detected in serum proportional to the number of implants placed. The response, however, was similar among all three dose levels, with testosterone and luteinizing hormone essentially completely suppressed. Serum testosterone levels decreased from 21.9 +/- 17.6 nmol/L to 0.93 +/- 1.57 nmol/L within 1 month and were maintained at 0.55 +/- 0.24 nmol/L at 6 months and 0.60 +/- 0.28 nmol/L after 12 months of treatment. Of the 38 assessable patients, 35 (92%) had castrate levels of testosterone within 4 weeks of the initial implant placement. All patients followed for up for 12 months after placement of the initial set of implants maintained suppression of testosterone production while the implant was in place.

CONCLUSIONS

The histrelin hydrogel implant provided adequate and reliable delivery of the potent GnRH agonist histrelin during at least 1 year using a single implant in men with prostate cancer. No apparent advantages were found in using more than one implant, and the question of the possible effectiveness of even lower doses remains open. This treatment modality appears to be both safe and effective.