Comparison of intermittent and continuous androgen deprivation and quality of life between patients with locally advanced and patients with metastatic prostate cancer: a post hoc analysis of the randomized FinnProstate Study VII

PRESTO: A Phase III, Open-Label Study of Intensification of Androgen Blockade in Patients With High-Risk Biochemically Relapsed Castration-Sensitive Prostate Cancer (AFT-19)

PURPOSE

Patients with biochemically recurrent prostate cancer (BRPC) after radical prostatectomy and a short PSA doubling time are at risk for distant metastases. Apalutamide, an androgen receptor antagonist, and abiraterone acetate plus prednisone (AAP) prolong survival in the metastatic setting. We evaluated whether intensification of androgen-deprivation therapy (ADT) improves outcomes in BRPC.

PATIENTS AND METHODS

PRESTO is a randomized phase III, open-label trial in patients with BRPC and PSA doubling time ≤9 months (ClinicalTrials.gov identifier: NCT03009981). Patients were randomly assigned 1:1:1 to receive a finite 52-week treatment course with ADT control, ADT + apalutamide, or ADT + apalutamide + AAP. The primary end point was PSA progression-free survival (PSA-PFS), defined as serum PSA >0.2 ng/mL after treatment completion.

RESULTS

Five hundred three patients were enrolled. The median PSA was 1.8 ng/mL (IQR, 1.0-3.6). At the first planned interim analysis, both experimental arms significantly prolonged PSA-PFS compared with the control arm (median, 24.9 months for ADT + apalutamide v 20.3 months for ADT; hazard ratio [HR], 0.52 [95% CI, 0.35 to 0.77]; P = .00047; median, 26.0 months for ADT + apalutamide + AAP v 20.0 months for ADT; HR, 0.48 [95% CI, 0.32 to 0.71]; P = .00008). Median time to testosterone recovery did not differ across treatment arms. The most common grade ≥3 adverse event was hypertension (7.5%, 7.4%, and 18% in ADT, ADT + apalutamide, and ADT + apalutamide + AAP arms, respectively).

CONCLUSION

Intensified AR blockade for a finite duration prolongs PSA-PFS with a manageable safety profile, without adversely affecting time to testosterone recovery. The addition of apalutamide to ADT should be considered in patients with high-risk BRPC.

A review of clinical evidence to assess differences in efficacy and safety of luteinizing hormone-releasing hormone (LHRH) agonist (goserelin) and LHRH antagonist (degarelix)

Luteinizing hormone-releasing hormone agonist (LHRH-A), goserelin, and antagonist, degarelix, are both indicated for the treatment of advanced prostate cancer (PCa); however, large comparative trials evaluating their efficacy and safety are lacking. In this review, we assessed the available evidence for both the drugs. Although degarelix achieves an early rapid decline in testosterone (T) and prostate-specific antigen (PSA) levels, median T and PSA levels, in addition to prostate volume and International Prostate Symptom Scores, become comparable with goserelin over the remaining treatment period. Degarelix causes no initial flare, therefore it is recommended in patients with spinal metastases or ureteric obstruction. Goserelin achieves lower PSA, improved time to progression, and better survival outcomes when administered adjunctively to radiotherapy compared with radiotherapy alone, with significant results even over long-term follow-up. The evidence supporting adjuvant degarelix use is limited. Goserelin has better injection site safety, single-step delivery, and an efficient administration schedule compared with degarelix, which has significantly higher injection site reactions and less efficient administration mechanism. There is conflicting evidence about the risk of cardiovascular disease (CVD), and caution is required when using LHRH-A in patients with preexisting CVD. There is considerable long-term evidence for goserelin in patients with advanced PCa, with degarelix being a more recent option. The available comparative evidence of goserelin versus degarelix has several inherent limitations related to study design, sample size, conduct, and statistical analyses, and hence warrants robust prospective trials and long-term follow-up.

Initial Management of Noncastrate Advanced, Recurrent, or Metastatic Prostate Cancer: ASCO Guideline Update

PURPOSE

Update all preceding ASCO guidelines on initial hormonal management of noncastrate advanced, recurrent, or metastatic prostate cancer.

METHODS

The Expert Panel based recommendations on a systematic literature review. Recommendations were approved by the Expert Panel and the ASCO Clinical Practice Guidelines Committee.

RESULTS

Four clinical practice guidelines, one clinical practice guidelines endorsement, 19 systematic reviews with or without meta-analyses, 47 phase III randomized controlled trials, nine cohort studies, and two review papers informed the guideline update.

RECOMMENDATIONS

Docetaxel, abiraterone, enzalutamide, or apalutamide, each when administered with androgen deprivation therapy (ADT), represent four separate standards of care for noncastrate metastatic prostate cancer. Currently, the use of any of these agents in any particular combination or series cannot be recommended. ADT plus docetaxel, abiraterone, enzalutamide, or apalutamide should be offered to men with metastatic noncastrate prostate cancer, including those who received prior therapies, but have not yet progressed. The combination of ADT plus abiraterone and prednisolone should be considered for men with noncastrate locally advanced nonmetastatic prostate cancer who have undergone radiotherapy, rather than castration monotherapy. Immediate ADT may be offered to men who initially present with noncastrate locally advanced nonmetastatic disease who have not undergone previous local treatment and are unwilling or unable to undergo radiotherapy. Intermittent ADT may be offered to men with high-risk biochemically recurrent nonmetastatic prostate cancer. Active surveillance may be offered to men with low-risk biochemically recurrent nonmetastatic prostate cancer. The panel does not support use of either micronized abiraterone acetate or the 250 mg dose of abiraterone with a low-fat breakfast in the noncastrate setting at this time.Additional information is available at www.asco.org/genitourinary-cancer-guidelines.

Intermittent versus continuous androgen deprivation therapy for advanced prostate cancer

Androgen deprivation therapy (ADT) is still a mainstay of treatment for advanced prostate cancer. Continuous ADT causes considerable patient morbidity including sexual dysfunction, poor mood and physical capacity, changes in body composition and health-care-related costs. Intermittent ADT has been used as an approach to ADT monotherapy to limit morbidity by enabling cyclical recovery of serum testosterone levels. To date, a number of well-performed randomized controlled trials and meta-analyses have demonstrated statistically insignificant differences in oncological outcomes between intermittent and continuous ADT monotherapy. Sexual outcomes, morbidity profiles and cost-savings favour intermittent therapy in most randomized trials, but the benefit for clinical practice is unclear. Despite the growing body of evidence, the optimal administration regime for ADT has not been clearly established and incorporation of adjunctive upfront treatments such as chemotherapy and novel anti-androgen agents has further hampered progress. Recommendations by authoritative urological and oncological societies regarding the use of intermittent ADT are limited. The potential benefits of reduced morbidity for a particular patient must be considered in light of the possible oncological outcomes. Although the oncological changes associated with intermittent ADT are controversial, intermittent ADT does seem to provide symptomatic benefit in patients compared with continuous ADT. However, careful selection of suitable patients is crucial.

Androgen-targeted therapy in men with prostate cancer: evolving practice and future considerations

Background

Androgen deprivation therapy (ADT) is foundational in the management of advanced prostate cancer (PCa) and has benefitted from a recent explosion in scientific advances. These include approval of new therapies that suppress testosterone (T) levels or inactivate its function, improvements in diagnostic and assay technologies, identification of lower therapeutic targets for T, discovery of the relevance of germline genetic mutations and identification of the benefits of sequential and combination therapies.

Methods

This review discusses the clinical profiles of the most up-to-date options for ADT, best practices for managing patients with advanced PCa and future directions in therapy.

Results and conclusions

Modern assay technologies reveal that bilateral orchiectomy results in a serum T level of approximately 15 ng/dL as compared to the historical definition of castration of T < 50 ng/dL. Evidence shows that lowering T levels to <20 ng/dL improves patient survival and delays disease progression. Routine monitoring of T in addition to prostate-specific antigen throughout treatment is important to ensure continuing efficacy of T suppression. New drugs that inhibit androgen signaling in combination with traditional ADT suppress T activity to near zero and have significantly improved patient survival. When personalizing ADT regimens physicians should consider a number of factors including initiation and duration of ADT, monitoring of T levels and PSA, the possibility of switching monotherapies if a patient does not achieve adequate T suppression, and consideration of intermittent vs. continuous ADT according to patients’ lifestyles, comorbidities, risk factors and tolerance to treatment.

Intermittent, low-dose, antiandrogen monotherapy as an alternative therapeutic option for patients with positive surgical margins after radical prostatectomy

The aim of the present study was to determine whether oncologic outcomes and adverse events associated with active on/off intermittent antiandrogen monotherapy (daily bicalutamide, 50 mg per day) are comparable with those of standard external beam radiation therapy (EBRT) or combined androgen blockade (CAB) therapy in prostate cancers with positive surgical margins after radical prostatectomy. Two hundred twenty-three patients with positive surgical margins post-radical prostatectomy who underwent active surveillance (AS, n = 32), EBRT without hormone therapy (n = 55), intermittent antiandrogen monotherapy without EBRT (IAAM, n = 50), or CAB without EBRT (n = 86), between 2007 and 2014, were reviewed retrospectively. Pathologic outcomes, biochemical recurrence rates, radiological disease progression, and adverse events were collected from medical records. Biochemical recurrence rates, biochemical recurrence-free survival rates, and radiological recurrence were not different between the groups (P = 0.225, 0.896, and 0.284, respectively). Adverse event rates and severities were lower for IAAM compared with EBRT or CAB (both P < 0.05), but were comparable to those for AS (P = 0.591 and 0.990, respectively). Grade ≥3 adverse events were not reported in the IAAM or AS groups. Erectile dysfunction and loss of libido rates were lower in the IAAM group compared with the EBRT and CAB groups (P = 0.032). Gastrointestinal complications were more frequently reported in the EBRT group (P = 0.008). Active on/off IAAM treatment might be an appropriate treatment option for patients with positive surgical margins after radical prostatectomy. Furthermore, regarding oncologic outcomes, IAAM was comparable to standard EBRT but had a milder adverse event profile.

Clinical characteristics and quality-of-life in patients surviving a decade of prostate cancer with bone metastases

OBJECTIVE

To describe characteristics and quality-of-life (QoL), and to define factors associated with long-term survival in a subgroup of patients with prostate cancer with M1b disease.

PATIENTS AND METHODS

The study was based on 915 patients from a prospective randomised multicentre trial (No. 5) by the Scandinavian Prostate Cancer Group, comparing parenteral oestrogen with total androgen blockade. Long-term survival was defined as patients having an overall survival of ≥10 years, and logistic regression models were constructed to identity clinical predictors of survival. QoL during follow-up was assessed using the European Organisation for Research and Treatment of Cancer Quality-of-Life Questionnaire - C30 version 1 (EORTC-C30) ratings.

RESULTS

In all, 40 (4.4%) of the 915 men survived for >10 years. Factors significantly associated with increased likelihood of surviving for >10 years in the univariate analyses were: absence of cancer-related pain; Eastern Cooperative Oncology Group (ECOG) performance status of <2; negligible analgesic consumption; T-category of 1-2; prostate-specific antigen (PSA) level of <231 μg/L; and a Soloway score of 1. In the multivariate analyses, ECOG performance status of <2, PSA level of <231 μg/L, and Soloway score of 1, were all independent predictors of long-term survival. All subscales of the EORTC-C30 were higher in this group than for patients with short survival, but slowly declined over the decade.

CONCLUSION

A subgroup of patients with prostate cancer with M1b disease and certain characteristics showed a positive long-term response to androgen-deprivation therapy with an acceptable QoL over a decade or more. Independent predictors of long-term survival were identified as ECOG performance status of <2, limited extent of bone metastases (Soloway score of 1), and a PSA level of <231 μg/L at the time of enrolment.