Risks and benefits of hormonal manipulation as monotherapy or adjuvant treatment in localised prostate cancer

Molecular Profiles of Prostate Cancer: To Treat or Not to Treat

A major dilemma in the selection of treatment for men with prostate cancer is the difficulty in accurately characterizing the risk posed by the cancer. This uncertainty has led physicians to recommend aggressive therapy for most men diagnosed with prostate cancer and has led to concerns about the benefits of screening and the adverse consequences of excessive treatment. Genomic analyses of prostate cancer reveal distinct patterns of alterations in the genomic landscape of the disease that show promise for improved prediction of prognosis and better medical decision making. Several molecular profiles are now commercially available and are being used to inform medical decisions. This article describes the clinical tests available for distinguishing aggressive from nonaggressive prostate cancer, reviews the new genomic tests, and discusses their advantages and limitations and the evidence for their utility in various clinical settings.

Hormone replacement therapy and longevity

To assess whether hormone replacement therapy influences longevity, an analysis was made of published life tables allowing for the calculation of the relative benefit of hormone replacement therapy on longevity in men with late onset hypogonadism and in post-menopausal women. It was found that testosterone replacement therapy of men suffering from late onset hypogonadism increased survival rate by 9-10% in 5 years, similar to that of eugonadal, non-LOH men with normal endogenous testosterone secretion. Oestrogen replacement therapy resulted in increased survival by 2.6% in 5 years. It is concluded that hormone replacement therapy increases longevity.

Survival benefit of early androgen receptor inhibitor therapy in locally advanced prostate cancer: long-term follow-up of the SPCG-6 study

BACKGROUND

The optimal timing of endocrine therapy in non-metastatic prostate cancer (PCa) is still an issue of debate.

METHODS

A randomised, double-blind, parallel-group trial comparing bicalutamide 150mg once daily with placebo in addition to standard care in patients with hormone-naïve, non-metastatic PCa. Kaplan-Meier analysis was used to estimate overall survival (OS) and multivariate Cox proportional hazard model was performed to analyse time-to-event (death).

FINDINGS

A total of 1218 patients were included into the Scandinavian Prostate Cancer Group (SPCG)-6 study of which 607 were randomised to receive bicalutamide in addition to their standard care and 611 to receive placebo. Median follow-up was 14.6years. Overall, 866 (71.1%) patients died, 428 (70.5%) in the bicalutamide arm and 438 (71.7%) in the placebo arm, p=0.87. Bicalutamide significantly improved OS in patient with locally advanced disease (hazard ratios (HR)=0.77 (95% confidence interval (CI): 0.63-0.94, p=0.01), regardless of baseline prostate-specific antigen (PSA), with a survival benefit which was apparent throughout the study period. In contrast, survival favoured randomisation to the placebo arm in patients with localised disease (HR=1.19 (95% CI: 1.00-1.43), p=0.056). However, a survival gain from bicalutamide therapy was present in patients with localised disease and a baseline PSA greater than 28ng/mL at randomisation. In multivariate Cox proportional hazard model, only including patients managed on watchful waiting as their standard of care (n=991) OS depended on age, World Health Organisation (WHO) grade, baseline PSA, clinical stage and randomised treatment.

INTERPRETATION

Throughout the 14.6year follow-up period the addition of early bicalutamide to standard of care resulted in a significant OS benefit in patients with locally advanced PCa. In contrast, patients with localised PCa and low PSA derived no survival benefit from early bicalutamide. The optimal timing for initiating bicalutamide in non-metastatic PCa patients is dependent on disease stage and baseline PSA.

Non-steroidal antiandrogen monotherapy compared with luteinising hormone-releasing hormone agonists or surgical castration monotherapy for advanced prostate cancer

BACKGROUND

Non-steroidal antiandrogens and castration are the main therapy options for advanced stages of prostate cancer. However, debate regarding the value of these treatment options continues.

OBJECTIVES

To assess the effects of non-steroidal antiandrogen monotherapy compared with luteinising hormone-releasing hormone agonists or surgical castration monotherapy for treating advanced stages of prostate cancer.

SEARCH METHODS

We searched the Cochrane Prostatic Diseases and Urologic Cancers Group Specialized Register (PROSTATE), the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Web of Science with Conference Proceedings, three trial registries and abstracts from three major conferences to 23 December 2013, together with reference lists, and contacted selected experts in the field and manufacturers.

SELECTION CRITERIA

We included randomised controlled trials comparing non-steroidal antiandrogen monotherapy with medical or surgical castration monotherapy for men in advanced stages of prostate cancer.

DATA COLLECTION AND ANALYSIS

One review author screened all titles and abstracts; only citations that were clearly irrelevant were excluded at this stage. Then, two review authors independently examined full-text reports, identified relevant studies, assessed the eligibility of studies for inclusion, assessed trial quality and extracted data. We contacted the study authors to request additional information. We used Review Manager 5 for data synthesis and used the fixed-effect model for heterogeneity less than 50%; we used the random-effects model for substantial or considerable heterogeneity.

MAIN RESULTS

Eleven studies involving 3060 randomly assigned participants were included in this review. The quality of evidence is hampered by risk of bias. Use of non-steroidal antiandrogens decreased overall survival (hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.05 to 1.48, six studies, 2712 participants) and increased clinical progression (one year: risk ratio (RR) 1.25, 95% CI 1.08 to 1.45, five studies, 2067 participants; 70 weeks: RR 1.26, 95% CI 1.08 to 1.45, six studies, 2373 participants; two years: RR 1.14, 95% CI 1.04 to 1.25, three studies, 1336 participants), as well as treatment failure (one year: RR 1.19, 95% CI 1.02 to 1.38, four studies, 1539 participants; 70 weeks: RR 1.27, 95% CI 1.05 to 1.52, five studies, 1845 participants; two years: RR 1.14, 95% CI 1.05 to 1.24, two studies, 808 participants), compared with medical or surgical castration. The quality of evidence for overall survival, clinical progression and treatment failure was rated as moderate according to GRADE. Predefined subgroup analyses showed that use of non-steroidal antiandrogens, compared with castration, was less favourable for overall survival, clinical progression (at one year, 70 weeks, two years) and treatment failure (at one year, 70 weeks, two years) in men with metastatic disease. Use of non-steroidal antiandrogens also increased the risk for treatment discontinuation due to adverse events (RR 1.82, 95% CI 1.13 to 2.94, eight studies, 1559 participants), including events such as breast pain (RR 22.97, 95% CI 14.79 to 35.67, eight studies, 2670 participants), gynaecomastia (RR 8.43, 95% CI 3.19 to 22.28, nine studies, 2774 participants) and asthenia (RR 1.77, 95% CI 1.36 to 2.31, five studies, 2073 participants). The risk of other adverse events, such as hot flashes (RR 0.23, 95% CI 0.19 to 0.27, nine studies, 2774 participants), haemorrhage (RR 0.07, 95% CI 0.01 to 0.54, two studies, 546 participants), nocturia (RR 0.38, 95% CI 0.20 to 0.69, one study, 480 participants), fatigue (RR 0.52, 95% CI 0.31 to 0.88, one study, 51 participants), loss of sexual interest (RR 0.50, 95% CI 0.30 to 0.83, one study, 51 participants) and urinary frequency (RR 0.22, 95% CI 0.11 to 0.47, one study, 480 participants) was decreased when non-steroidal antiandrogens were used. The quality of evidence for breast pain, gynaecomastia and hot flashes was rated as moderate according to GRADE. The effects of non-steroidal antiandrogens on cancer-specific survival and biochemical progression remained unclear.

AUTHORS' CONCLUSIONS

Currently available evidence suggests that use of non-steroidal antiandrogen monotherapy compared with medical or surgical castration monotherapy for advanced prostate cancer is less effective in terms of overall survival, clinical progression, treatment failure and treatment discontinuation due to adverse events. Evidence quality was rated as moderate according to GRADE. Further research is likely to have an important impact on results for patients with advanced but non-metastatic prostate cancer treated with non-steroidal antiandrogen monotherapy. However, we believe that research is likely not necessary on non-steroidal antiandrogen monotherapy for men with metastatic prostate cancer. Only high-quality, randomised controlled trials with long-term follow-up should be conducted. If further research is planned to investigate biochemical progression, studies with standardised follow-up schedules using measurements of prostate-specific antigen based on current guidelines should be conducted.

Treatment of localized prostate cancer: when is active surveillance appropriate?

Testing for prostate-specific antigen (PSA) has caused a dramatic increase in the incidence of prostate cancer during the past two decades. Many cancers identified by repeated PSA testing are small volume, low-grade lesions that pose little threat of progression over 15-20 years. Data from a recently reported randomized trial indicate that as many as 48 men must undergo treatment to prevent one prostate cancer-related death. Unfortunately, no test is currently available that can identify those men who have clinically significant disease. Men least likely to experience disease progression are men who harbor tumors with a Gleason score of 6 involving 2 needle cores or less; these men may want to consider active surveillance as their initial treatment option. Researchers have followed over 2,500 men on active surveillance protocols (over 200 men have been followed for >10 years). To date, prostate cancer-specific survival is over 99%. About 25% of men enrolled in active surveillance programs have abandoned this approach because of concerns about disease progression. For men harboring tumors with a Gleason score >7, data from two recently reported Swedish trials suggest lower prostate cancer-related mortality for those men receiving either surgery or radiation.

Patient rationale in selecting androgen deprivation (PRISAD): do we give patients what they want?

To assess patient rationale in selecting androgen deprivation, structured telephone interviews were conducted on consecutive patients on androgen deprivation over a 17-year period. The majority of these patients have stable disease that require long-term follow-up with 6-monthly PSA estimations. Synchronous PSA check with depot injections are preferred by majority of patients and longer intervals between the depot administrations are preferable due to perceived less needle pain. This study highlights for the first time patients' preferences for synchronous PSA check with their depot injections and a longer interval between the depot administrations due to perceived less needle pain.

Tamoxifen as Prophylaxis for Prevention of Gynaecomastia and Breast Pain Associated with Bicalutamide 150mg Monotherapy in Patients with Prostate Cancer: A Randomised, Placebo-Controlled, Dose–Response Study

OBJECTIVE

To define the optimum tamoxifen dose for reducing bicalutamide (CASODEX) 150 mg monotherapy-induced breast events (ie, gynaecomastia or breast pain or both) without compromising disease control.

METHODS

This was a double-blind, parallel-group, multicentre trial in which 282 patients with prostate cancer were randomised to receive bicalutamide 150 mg/d plus either daily tamoxifen (1, 2.5, 5, 10, or 20mg) or placebo for 12 mo, followed by 12 mo of treatment with bicalutamide only. Primary end points were incidence of breast events and prostate-specific antigen (PSA) inhibition and were analysed at 6 mo (the primary analysis) and also at 12 and 24 mo.

RESULTS

At 6 and 12 mo, tamoxifen decreased the incidence of breast events in a dose-dependent manner, with breast events observed in 86.2%, 60.0%, 55.3%, 23.5%, and 8.8% of patients receiving tamoxifen 1, 2.5, 5, 10, and 20 mg, respectively, compared with 96.7% of patients receiving placebo at 6 mo. At 24 mo (ie, after 12 mo of bicalutamide monotherapy), a high incidence of breast events was seen in all groups. There was no evidence of a negative effect on PSA inhibition at any assessment. Other nonbreast adverse effects were similar across groups, except for an increase in hot flushes with tamoxifen doses > or =5 mg.

CONCLUSION

These findings suggest that prophylactic tamoxifen 20 mg/d is an effective dose for reduction of bicalutamide-induced breast events and does not appear to affect disease control based on PSA suppression.

Does the molecular staging in pelvic lymph nodes improve the detection of relevant prostate cancer metastases? An assessment after 6 years

OBJECTIVE

To assess the course of cancer-free survival and thus determine how reliably reverse transcriptase-polymerase chain reaction (RT-PCR) can detect prostate-specific antigen (PSA)-expressing cells, as patients with untreated lymph node-positive prostate cancer tend to have a poor prognosis, whereas those treated with radical prostatectomy (RP) and immediate adjuvant hormonal therapy show excellent local disease control and a disease-free survival comparable with that of patients with negative lymph nodes, but the detection of micrometastatic disease in pelvic lymph nodes remains a major challenge.

PATIENTS AND METHODS

Quantitative RT-PCR was used to detect PSA mRNA expression in total RNA of 457 pelvic lymph nodes from 70 patients who had RP (53 patients) or laparoscopic lymphadenectomy (17) at our clinic in 1999/2000. For this purpose, alternate sections of lymph node tissue were either snap-frozen for later RNA isolation or examined by standard histopathological methods. Clinicopathological data, adjuvant treatments and follow-up data were recorded for all patients.

RESULTS

After January 2006 (6-year observation period), 13 patients had no follow-up data, while 27 had biochemical (PSA) recurrence or other evidence of clinical progression (two died from prostate cancer), and 30 had no signs of recurrence. Compared to the 'reference' standard (histopathology), the PCR method had a sensitivity of 83% and a specificity of 66%. The method had a positive predictive value of 52% and a negative predictive value of 57%.

CONCLUSION

Considered alone, pelvic lymph node PSA RT-PCR does not predict the clinical course better than a histopathological assessment of lymph nodes. However, it also identifies some patients with negative histology who later show progression. When added to the pathological classification, PSA RT-PCR improves the detection rate of primary lymphatic dissemination.

A Randomized Phase III Study of Neoadjuvant Hormonal Therapy in Patients with Localized Prostate Cancer

The primary objective of this randomized trial is to evaluate the benefit of the addition of neoadjuvant hormonal therapy to escalated-dose external-beam radiation therapy in the treatment of patients with intermediate-risk carcinoma of the prostate. A secondary objective of this study is to determine prognostic factors for radiation response. All patients will have tissue oxygenation measured and biopsies taken before treatment at the time of fiducial marker insertion for radiation treatment planning and daily monitoring. In addition, patients randomized to the neoadjuvant bicalutamide arm will be asked to consider having these studies repeated before initiation of radiation therapy (after 3 months of hormonal therapy).

Prostate cancer-specific survival in men treated with hormonal therapy after failure of radical prostatectomy

OBJECTIVES

We hypothesized that prostate cancer-specific survival (PCaSS) could be accurately predicted in men in whom radical prostatectomy (RP) failed and who received hormonal therapy (HT) after RP failure.

METHODS

Between 1954 and 1994, 752 consecutive patients underwent RP without neoadjuvant therapy. Of those, 114 patients (15.2%) received HT at RP failure and represent the focus of this analysis. Cox regression models and a nomogram targeted PCaSS. The main predictor was timing of HT initiation: at prostate-specific antigen (PSA) versus local versus distant recurrence. Covariates included age at HT, pathologic T stage, surgical margin status and Gleason sum at RP, use of adjuvant or salvage radiation, and time from RP to HT.

RESULTS

Mean and median follow-up periods were 5.1 and 3.9 yr; 70 deaths were recorded, of which 45 (39.8%) were due to PCa. At 1, 5, 10, and 15 yr, the estimates of PCaSS were, respectively, 97.1%, 68.3%, 49.3%, and 30.2% (median, 9.8 yr). Younger men and those with HT initiated at the time of distant recurrence had lower PCaSS. A nomogram predicting PCaSS at 2, 3, 4, and 5 yr after RP was developed and demonstrated 66% accuracy after 200-bootstrap internal validation.

CONCLUSION

Despite RP failure, half the patients can expect to survive for 10 yr. The nomogram can help in discriminating between those with better versus worse PCaSS, better than relying on most educated guesses.

Clinical implications of neuroendocrine differentiation in prostate cancer

The cellular signaling pathways of the prostate play a central role in the induction, maintenance, and progression of prostate cancer (CaP). Neuroendocrine (NE) cells demonstrate attributes that suggest they are an integral part of these signaling cascades. We summarize what is known regarding NE cells in CaP focusing on NE cellular transdifferentiation. This significant event in CaP progression appears to be accelerated by androgen deprivation (AD) treatment. We examine biochemical pathways that may impact NE differentiation in a chronological manner focusing on AD therapy (ADT) as a central event in inducing androgen-independent CaP. Our analysis is limited to the common adenocarcinoma pattern of CaP and excludes small-cell and carcinoid prostatic variants. In conclusion, we speculate on the future of treatment and research in this area.