The Evolving Role of Oestrogens and Their Receptors in the Development and Progression of Prostate Cancer

Context

Oestrogens were proven effective in the hormonal treatment of advanced prostate cancer (PCa) >60 yr ago and are still used as second-line hormonal therapy. Paradoxically, oestrogens might also be involved in the development and progression of PCa.

Objective

To examine mechanisms of how oestrogens may affect prostate carcinogenesis and tumour progression.

Evidence acquisition

Recent data obtained from animal, experimental, and clinical studies were reviewed.

Evidence synthesis

The human prostate is equipped with a dual system of oestrogen receptors (oestrogen receptor alpha [ERα], oestrogen receptor beta [ERβ]) that undergoes profound remodelling during PCa development and tumour progression. In high-grade prostatic intraepithelial neoplasia (HGPIN), the ERα is upregulated and most likely mediates carcinogenic effects of estradiol as demonstrated in animal models. Preliminary clinical studies with the ERα antagonist toremifene have identified the ERα as a promising target for PCa prevention. The partial loss of the ERβ in HGPIN indicates that the ERβ acts as a tumour suppressor. The ERβ is generally retained in hormone-naïve PCa but is partially lost in castration-resistant disease. The progressive emergence of the ERα and the oestrogen-regulated progesterone receptor (PR) during PCa progression and hormone-refractory disease suggests that these tumours can use oestrogens and progestins for their growth. The TMPRSS2-ERG gene fusion recently reported as a potentially aggressive molecular subtype of PCa is regulated by ER-dependent signalling. TMPRSS2-ERG expression has been found to be increased by ERα agonist (oestrogens) and decreased by ERβ agonists.

Conclusions

Oestrogens and their receptors are implicated in PCa development and tumour progression. There is significant potential for the use of ERα antagonists and ERβ agonists to prevent PCa and delay disease progression. Tumours equipped with the pertinent receptors are potential candidates for this new therapeutic approach.     

External Validation of Urinary PCA3-Based Nomograms to Individually Predict Prostate Biopsy Outcome

Background

Prior to safely adopting risk stratification tools, their performance must be tested in an external patient cohort.

Objective

To assess accuracy and generalizability of previously reported, internally validated, prebiopsy prostate cancer antigen 3 (PCA3) gene-based nomograms when applied to a large, external, European cohort of men at risk of prostate cancer (PCa).

Design, setting, and participants

Biopsy data, including urinary PCA3 score, were available for 621 men at risk of PCa who were participating in a European multi-institutional study.

Intervention

All patients underwent a ≥10-core prostate biopsy. Biopsy indication was based on suspicious digital rectal examination, persistently elevated prostate-specific antigen level (2.5–10 ng/ml) and/or suspicious histology (atypical small acinar proliferation of the prostate, >/= two cores affected by high-grade prostatic intraepithelial neoplasia in first set of biopsies).

Measurements

PCA3 scores were assessed using the Progensa assay (Gen-Probe Inc, San Diego, CA, USA). According to the previously reported nomograms, different PCA3 score codings were used. The probability of a positive biopsy was calculated using previously published logistic regression coefficients. Predicted outcomes were compared to the actual biopsy results. Accuracy was calculated using the area under the curve as a measure of discrimination; calibration was explored graphically.

Results and limitations

Biopsy-confirmed PCa was detected in 255 (41.1%) men. Median PCA3 score of biopsy-negative versus biopsy-positive men was 20 versus 48 in the total cohort, 17 versus 47 at initial biopsy, and 37 versus 53 at repeat biopsy (all p ≤ 0.002). External validation of all four previously reported PCA3-based nomograms demonstrated equally high accuracy (0.73–0.75) and excellent calibration. The main limitations of the study reside in its early detection setting, referral scenario, and participation of only tertiary-care centers.

Conclusions

In accordance with the original publication, previously developed PCA3-based nomograms achieved high accuracy and sufficient calibration. These novel nomograms represent robust tools and are thus generalizable to European men at risk of harboring PCa. Consequently, in presence of a PCA3 score, these nomograms may be safely used to assist clinicians when prostate biopsy is contemplated.     

Performance of the Prostate Cancer Antigen 3 (PCA3) Gene and Prostate-Specific Antigen in Prescreened Men: Exploring the Value of PCA3 for a First-line Diagnostic Test

Background

The performance characteristics of serum prostate-specific antigen (PSA) as a diagnostic test for prostate cancer (PCa) are poor. The performance of the PCa antigen 3 (PCA3) gene as a primary diagnostic is unknown.

Objective

Assess the value of PCA3 as a first-line diagnostic test.

Design, setting and participants

Participants included men aged 63–75 who were invited for rescreening in the period from September 2007 to February 2009 within the European Randomised Study of Screening for Prostate Cancer, Rotterdam section.

Interventions

Lateral sextant biopsies were performed if the serum PSA value was ≥3.0 ng/ml and/or the PCA3 score was ≥10.

Measurements

Measurements included distribution and correlation of PSA value and PCA3 score and their relation to the number of cases and the characteristics of PCa detected. Additional value of PCA3 was included in men with previous negative biopsy and/or PSA <3.0 ng/ml.

Results and limitations

In 721 men, all biopsied, 122 PCa cases (16.9%) were detected. Correlation between PSA and PCA3 is poor (Spearman rank correlation: ρ = 0.14; p < 0.0001). A PSA ≥3.0 ng/ml misses 64.7% of the total PCa that can be detected with the sextant biopsy technique and 57.9% of serious PCa (T2a or higher and/or Gleason grade ≥4, n = 19), and 68.2% of biopsies could have been avoided; the respective data for PCA3 ≥35 are 32%, 26.3%, and 51.7%. Performance of PCA3 in men with low PSA (area under the curve [AUC]: 0.63) and/or previous negative biopsy (AUC: 0.68) is unclear but has limited reliability due to small numbers.

Conclusions

PCA3 as a first-line screening test shows improvement of the performance characteristics and identification of serious disease compared with PSA in this prescreened population.     

Pelvic Lymph Node Dissection in Prostate Cancer

Context

Pelvic lymph node dissection (PLND) is considered the most reliable procedure for the detection of lymph node metastases in prostate cancer (PCa); however, the therapeutic benefit of PLND in PCa management is currently under debate.

Objective

To systematically review the available literature concerning the role of PLND and its extent in PCa staging and outcome. All of the existing recommendations and staging tools determining the need for PLND were also assessed. Moreover, a systematic review was performed of the long-term outcome of node-positive patients stratified according to the extent of nodal invasion.

Evidence acquisition

A Medline search was conducted to identify original and review articles as well as editorials addressing the significance of PLND in PCa. Keywords included prostate cancer, pelvic lymph node dissection, radical prostatectomy, imaging, and complications. Data from the selected studies focussing on the role of PLND in PCa staging and outcome were reviewed and discussed by all of the contributing authors.

Evidence synthesis

Despite recent advances in imaging techniques, PLND remains the most accurate staging procedure for the detection of lymph node invasion (LNI) in PCa. The rate of LNI increases with the extent of PLND. Extended PLND (ePLND; ie, removal of obturator, external iliac, hypogastric with or without presacral and common iliac nodes) significantly improves the detection of lymph node metastases compared with limited PLND (lPLND; ie, removal of obturator with or without external iliac nodes), which is associated with poor staging accuracy. Because not all patients with PCa are at the same risk of harbouring nodal metastases, several nomograms and tables have been developed and validated to identify candidates for PLND. These tools, however, are based mostly on findings derived from lPLND dissections performed in older patient series. According to these prediction models, a staging PLND might be omitted in low-risk PCa patients because of the low rate of lymph node metastases found, even after extended dissections (<8%). The outcome for patients with positive nodes is not necessarily poor. Indeed, patients with low-volume nodal metastases experience excellent survival rates, regardless of adjuvant treatment. But despite few retrospective studies reporting an association between PLND and PCa progression and survival, the exact impact of PLND on patient outcomes has not yet been clearly proven because of the lack of prospective randomised trials.

Conclusions

On the basis of current data, we suggest that if a PLND is indicated, then it should be extended. Conversely, in view of the low rate of LNI among patients with low-risk PCa, a staging ePLND might be spared in this patient category. Whether this approach is also safe from oncologic perspectives is still unknown. Patients with low-volume nodal metastases have a good long-term prognosis; to what extent this prognosis is the result of a positive impact of PLND on PCa outcomes is still to be determined.     

Phase 1 Trial of High-Dose Exogenous Testosterone in Patients with Castration-Resistant Metastatic Prostate Cancer

Background

Growth of selected castration-resistant prostate cancer (CRPC) cell lines and animal models can be repressed by reexposure to androgens. Low doses of androgens, however, can stimulate tumor growth.

Objective

We performed a phase 1 clinical trial to determine the safety of high-dose exogenous testosterone in patients with castration-resistant metastatic prostate cancer (CRMPC).

Design, setting, and participants

Patients with progressive CRMPC who had been castrate for at least 1 yr received three times the standard replacement dose of transdermal testosterone.

Intervention

Cohorts of 3–6 patients received testosterone for 1 wk, 1 mo, or until disease progression.

Measurements

Toxicities, androgen levels, prostate-specific antigen (PSA) assays, computed tomography (CT) scans, bone scintigraphy, positron emission tomography (PET) scans, and metastatic tumor biopsy androgen receptor levels were assessed.

Results and limitations

Twelve patients were treated—three in cohorts 1 and 2 and six in cohort 3. No pain flares were noted. One patient came off study because of epidural disease, which was treated with radiation. Average testosterone levels were within normal limits, although dihydrotestosterone (DHT) levels on average were supraphysiologic in cohort 3. One patient achieved a PSA decline of >50% from baseline. No objective responses were seen. For cohort 3, median time on treatment was 84 d (range: 23–247 d).

Conclusions

We have demonstrated that patients with CRMPC can be safely treated in clinical trials using high-dose exogenous testosterone. Patients did not, on average, achieve sustained supraphysiologic serum testosterone levels. Future studies should employ strategies to maximize testosterone serum levels, use contemporary methods of identifying patients with androgen receptor overexpression, and utilize PSA Working Group II Consensus Criteria clinical trial end points.

Trial registration

ClinicalTrials.gov; NCT00006044.     

A Randomized Phase 1 Study of Testosterone Replacement for Patients with Low-Risk Castration-Resistant Prostate Cancer

Background

Even in castration-resistant prostate cancer (CRPC), the androgen pathway remains biologically relevant. In preclinical models, androgen therapy for CRPC leads to growth arrest, apoptosis, and tumor shrinkage.

Objective

This study sought to determine the toxicity and feasibility of a testosterone therapy in early CRPC.

Design, setting, and participants

Prostate cancer patients with progressive disease following androgen ablation, antiandrogen therapy, and withdrawal and no to minimal metastatic disease who were followed at the University of Chicago were randomized to treatment with three doses of transdermal testosterone.

Intervention

Patients were treated with transdermal testosterone at 2.5, 5.0, or 7.5 mg/day.

Measurements

Toxicity, prostate-specific antigen (PSA), imaging, quality of life (QoL), and strength were monitored. Treatment was discontinued for significant toxicity, clinical progression, or a 3-fold increase in PSA.

Results and limitations

Fifteen men with a median age of 73 yr (range: 62–92) and a median PSA of 11.1 ng/ml (range: 5.2–63.6) were treated. Testosterone increased from castrate to median concentrations of 305 ng/dl, 308 ng/dl, and 297 ng/dl for dosages of 2.5 mg/day (n = 4), 5.0 mg/day (n = 5), and 7.5 mg/day (n = 5), respectively. One patient was taken off of the study at 53 wk due to grade 4 cardiac toxicity. There were no other grade 3 or 4 toxicities related to the study medication, and the grade 2 toxicities were minimal. Only one patient experienced symptomatic progression, and three (20%) patients demonstrated a decrease in PSA (largest was 43%). Median time to progression was 9 wk (range: 2–96), with no detectable difference in the three dose cohorts. There was no significant improvement in QoL, and there was a borderline statistically significant improvement in hand-grip strength with treatment. The study was limited by sample size, single arm, and variability of baseline patient characteristics.

Conclusions

Testosterone is a feasible and reasonably well-tolerated therapy for men with early CRPC. A larger, randomized trial is under way to further characterize efficacy and impact on QoL measures.     

Testosterone and Prostate Cancer: Revisiting Old Paradigms

Context

Androgens are vital for growth and maintenance of the prostate; however, the notion that pathologic prostate growth, benign or malignant, can be stimulated by androgens is a commonly held belief without scientific basis. Therefore, the current prostatic guidelines for testosterone therapy (TT) appear to be overly restrictive and should be reexamined.

Objective

To review the literature addressing the possible relationship between testosterone and prostate cancer (PCa) and to summarize the main aspects of this issue.

Evidence acquisition

A Medline search was conducted to identify original articles, review articles, and editorials addressing the relationship between testosterone and the risk of PCa development, as well as the impact of TT on PCa development and its natural history in men believed to be cured by surgery or radiation.

Evidence synthesis

Serum androgen levels, within a broad range, are not associated with PCa risk. Conversely, at time of PCa diagnosis, low rather than high serum testosterone levels have been found to be associated with advanced or high-grade disease. The available evidence indicates that TT neither increases the risk of PCa diagnosis nor affects the natural history of PCa in men who have undergone definitive treatment without residual disease. These findings can be explained with the saturation model (which states that prostatic homeostasis is maintained by a relatively low level of androgenic stimulation) and with the observation that exogenous testosterone administration does not significantly increase intraprostatic androgen levels in hypogonadal men. It must, however, be recognized that the literature remains limited regarding the effect of TT on PCa risk. Nonetheless, the current European Association of Urology guidelines state that in hypogonadal men who were successfully treated for PCa, TT can be considered after a prudent interval.

Conclusions

Although no controlled studies have yet been performed and there is a paucity of long-term data, the available literature strongly suggests that TT neither increases the risk of PCa diagnosis in normal men nor causes cancer recurrence in men who were successfully treated for PCa. Large prospective studies addressing the long-term effect of TT are needed to either refute or corroborate these hypotheses.     

The Updated EAU Guidelines on Muscle-Invasive and Metastatic Bladder Cancer

Context

New data regarding diagnosis and treatment of muscle-invasive and metastatic bladder cancer (MiM-BC) has emerged and led to an update of the European Association of Urology (EAU) guidelines for MiM-BC.

Objective

To review the new EAU guidelines for MiM-BC.

Evidence acquisition

A comprehensive workup of the literature obtained from Medline, the Cochrane central register of systematic reviews, and reference lists in publications and review articles was developed and screened by a group of urologists, oncologists, and radiologist appointed by the EAU Guideline Committee. Previous recommendations based on the older literature on this subject were taken into account. Levels of evidence and grade of guideline recommendations were added, modified from the Oxford Centre for Evidence-based Medicine Levels of Evidence.

Evidence synthesis

The diagnosis of muscle-invasive bladder cancer (BCa) is made by transurethral resection (TUR) and following histopathologic evaluation. Patients with confirmed muscle-invasive BCa should be staged by computed tomography (CT) scans of the chest, abdomen, and pelvis, if available. Adjuvant chemotherapy is currently only advised within clinical trials. Radical cystectomy (RC) is the treatment of choice for both sexes, and lymph node dissection should be an integral part of cystectomy. An orthotopic bladder substitute should be offered to both male and female patients lacking any contraindications, such as no tumour at the level of urethral dissection. Multimodality bladder-preserving treatment in localised disease is currently regarded only as an alternative in selected, well-informed, and compliant patients for whom cystectomy is not considered for clinical or personal reasons. An appropriate schedule for disease monitoring should be based on (1) natural timing of recurrence, (2) probability of disease recurrence, (3) functional deterioration at particular sites, and (4) consideration of treatment of a recurrence. In metastatic disease, the first-line treatment for patients fit enough to sustain cisplatin is cisplatin-containing combination chemotherapy. Presently, there is no standard second-line chemotherapy.

Conclusions

These EAU guidelines are a short, comprehensive overview of the updated guidelines of (MiM-BC) as recently published in the EAU guidelines and also available in the National Guideline Clearinghouse.     

Health-Related Quality of Life in the Finnish Trial of Screening for Prostate Cancer

Background

Evidence of the potential impact of systematic screening for prostate cancer (PCa) on health-related quality of life (HRQoL) at a population-based level is currently scarce.

Objective

This study aims to quantify the long-term HRQoL impact associated with screening for PCa.

Design, setting, and participants

Postal questionnaire surveys were conducted in 1998, 2000, 2004, and 2011 among men in the Finnish PCa screening trial diagnosed with PCa (total n = 7011) and among a random subsample of the trial population (n = 2200). In 2011, for example, 1587 responses were received from men with PCa in the screening arm and 1706 from men in the control arm. In addition, from the trial subsample, 549 men in the screening arm and 539 in the control arm provided responses.

Outcome measurements and statistical analysis

Health-state-value scores were compared between the intervention and control arms using three distinct HRQoL measures (15D, EQ-5D, and SF-6D), and statistical significance was assessed using t tests. In addition, differences over repeated assessments of HRQoL between groups were evaluated using generalised estimating equations.

Results and limitations

In the 2011 survey, a small but statistically significant difference emerged between the trial arms among men diagnosed with PCa (mean scores, screening vs control arm: 15D: 0.872 vs 0.866, p = 0.14; EQ-5D: 0.852 vs 0.831, p = 0.03; and SF-6D: 0.763 vs 0.756, p = 0.06). Such differences in favour of the screening arm were not found among the sample of men from the trial (15D: 0.889 vs 0.892, p = 0.62; EQ-5D: 0.831 vs 0.852, p = 0.08; and SF-6D: 0.775 vs 0.777, p = 0.88). The slight advantage with screening among men with PCa was reasonably consistent across time in the longitudinal analysis and was strongest among men with early-stage disease.

Conclusions

These results show some long-term HRQoL benefit from screening for men with PCa but suggest little impact overall in the trial population.     

Obesity and Prostate Cancer: Weighing the Evidence

Context

Obesity and prostate cancer (PCa) affect substantial proportions of Western society. Mounting evidence, both epidemiologic and mechanistic, for an association between the two is of public health interest. An improved understanding of the role of this modifiable risk factor in PCa etiology is imperative to optimize screening, treatment, and prevention.

Objective

To consolidate and evaluate the evidence for an epidemiologic link between obesity and PCa, in addition to examining the proposed underlying molecular mechanisms.

Evidence acquisition

A PubMed search for relevant articles published between 1991 and July 2012 was performed by combining the following terms: obesity, BMI, body mass index and prostate cancer risk, prostate cancer incidence, prostate cancer mortality, radical prostatectomy, androgen-deprivation therapy, external-beam radiation, brachytherapy, prostate cancer and quality of life, prostate cancer and active surveillance, in addition to obesity, BMI, body mass index and prostate cancer and insulin, insulin-like growth factor, androgen, estradiol, leptin, adiponectin, and IL-6. Articles were selected based on content, date of publication, and relevancy, and their references were also searched for relevant articles.

Evidence synthesis

Increasing evidence suggests obesity is associated with elevated incidence of aggressive PCa, increased risk of biochemical failure following radical prostatectomy and external-beam radiotherapy, higher frequency of complications following androgen-deprivation therapy, and increased PCa-specific mortality, although perhaps a lower overall PCa incidence. These results may in part relate to difficulties in detecting and treating obese men. However, multiple molecular mechanisms could explain these associations as well. Weight loss slows PCa in animal models but has yet to be fully tested in human trials.

Conclusions

Obesity appears to be linked with aggressive PCa. We suggest clinical tips to better diagnose and treat obese men with PCa. Whether reversing obesity slows PCa growth is currently unknown, although it is an active area of research.     

Reduction of Serum Prostate-Specific Antigen Levels following Varicella-Zoster Infection and Valaciclovir Treatment in Prostate Cancer

We present two prostate cancer patients, including one with a castration-resistant cancer whose rising serum prostate-specific antigen (PSA) levels showed a remarkable drop after a reactivated varicella-zoster virus infection treated with valaciclovir. In one patient, we found a temporary decrease in serum PSA lasting for at least 4 mo. In the patient with castration-resistant prostate cancer, serum PSA decreased to <0.01 μg/l and has remained undetectable since.     

Focal Therapy for Prostate Cancer: Possibilities and Limitations

Context

A significant proportion of patients diagnosed with prostate cancer have well-differentiated, low-volume tumors at minimal risk of impacting their quality of life or longevity. The selection of a treatment strategy, among the multitude of options, has enormous implications for individuals and health care systems.

Objective

Our aim was to review the rationale, patient selection criteria, diagnostic imaging, biopsy schemes, and treatment modalities available for the focal therapy of localized prostate cancer. We gave particular emphasis to the conceptual possibilities and limitations.

Evidence acquisition

A National Center for Biotechnology Information PubMed search (www.pubmed.gov) was performed from 1995 to 2009 using medical subject headings “focal therapy” or “ablative” and “prostate cancer.” Additional articles were extracted based on recommendations from an expert panel of authors.

Evidence synthesis

Focal therapy of the prostate in patients with low-risk cancer characteristics is a proposed treatment approach in development that aims to eradicate all known foci of cancer while minimizing damage to adjacent structures necessary for the preservation of urinary, sexual, and bowel function. Conceptually, focal therapy has the potential to minimize treatment-related toxicity without compromising cancer-specific outcome. Limitations include the inability to stage or grade the cancer(s) accurately, suboptimal imaging capabilities, uncertainty regarding the natural history of untreated cancer foci, challenges with posttreatment monitoring, and the lack of quality-of-life data compared with alternative treatment strategies. Early clinical experiences with modest follow-up evaluating a variety of modalities are encouraging but hampered by study design limitations and small sample sizes.

Conclusions

Prostate focal therapy is a promising and emerging treatment strategy for men with a low risk of cancer progression or metastasis. Evaluation in formal prospective clinical trials is essential before this new strategy is accepted in clinical practice. Adequate trials must include appropriate end points, whether absence of cancer on biopsy or reduction in progression of cancer, along with assessments of safety and longitudinal alterations in quality of life.     

Insignificant Prostate Cancer and Active Surveillance: From Definition to Clinical Implications

Context

Due to early detection strategies, prostate cancer is diagnosed early in its natural history. It remains unclear whether all patients diagnosed with prostate cancer warrant radical treatment or may benefit from delayed intervention following active surveillance.

Objective

A systematic review of active surveillance protocols to investigate the inclusion criteria for active surveillance and the outcome of treatment.

Evidence acquisition

Medline was searched using the following terms: prostate cancer, active surveillance and expectant management for dates up to October 2008. Further studies were chosen on the basis of manual searches of reference lists and review papers.

Evidence synthesis

Numerous studies on active surveillance were identified. The recent inclusion criteria of the studies are rather similar. Keeping the short follow-up of all studies in mind, the majority of men stay on active surveillance, and the percentage of patients receiving active treatment is as high as 35% of all patients. Once a patients requires active treatment, most patients still present with curable prostate cancer. Furthermore, only few deaths due to prostate cancer have occurred.

Conclusions

Active surveillance is an alternative option to immediate treatment of men with presumed insignificant prostate cancer. It seems that criteria used to identify men with low-risk prostate cancer are rather similar, and immediate treatment of men meeting these criteria may result in an unnecessary number of treatments in these highly selected patients. Data from randomised trials comparing active surveillance and active treatment will provide additional insight into outcome and follow-up strategies.     

The Influence of Prior Abiraterone Treatment on the Clinical Activity of Docetaxel in Men with Metastatic Castration-resistant Prostate Cancer

Background

Taxanes may partly mediate their effect in castration-resistant prostate cancer (CRPC) through disruption of androgen-receptor trafficking along microtubules. This raises the possibility of cross-resistance between androgen-directed agents and docetaxel.

Objective

To evaluate docetaxel efficacy after abiraterone treatment in CRPC patients.

Design, setting, and participants

This was a single-institution, retrospective analysis in CRPC patients (N = 119) who either received abiraterone before docetaxel (AD) (n = 24) or did not receive abiraterone before docetaxel (docetaxel-only; n = 95). Men initiated docetaxel between December 2007 (the date abiraterone was first used at our center) and May 2013.

Outcome measurements and statistical analysis

The primary efficacy end points were prostate-specific antigen progression-free survival (PSA-PFS) and clinical/radiographic progression-free survival (PFS) on docetaxel. Differences between groups were assessed using univariate and multivariable analyses.

Results and limitations

Men in the AD group had a significantly higher risk for progression than those in the docetaxel-only group. Median PSA-PFS was 4.1 mo in the AD group and 6.7 mo in the docetaxel-only group (p = 0.002). Median PFS was also shorter in the AD group (4.4 mo vs 7.6 mo; p = 0.003). In multivariable analysis, prior abiraterone treatment remained an independent predictor of shorter PSA-PFS (hazard ratio [HR]: 3.48; 95% confidence interval [CI], 1.36–8.94; p = 0.01) and PFS (HR: 3.62; 95% CI, 1.41–9.27; p = 0.008). PSA declines ≥50% were less frequent in the AD group (38% vs 63%; p = 0.02). The small size and retrospective nature of this study may have introduced bias.

Conclusions

Men receiving abiraterone before docetaxel were more likely to progress on docetaxel and less likely to achieve a PSA response than abiraterone-naïve patients. Cross-resistance between abiraterone and docetaxel may explain these findings; however, larger, more definitive studies are still needed to confirm this.

Patient summary

We examined the efficacy of docetaxel in castration-resistant prostate cancer patients who either did or did not receive prior abiraterone. We found that men receiving abiraterone before docetaxel were less likely to achieve a PSA response and were more likely to progress sooner on docetaxel than abiraterone-untreated patients. This may be due to cross-resistance.     

Systematic Review of the Efficacy and Safety of High-Intensity Focussed Ultrasound for the Primary and Salvage Treatment of Prostate Cancer

Context

High-intensity focussed ultrasound (HIFU) is an emerging minimally invasive treatment option for prostate cancer.

Objective

Our aim was to assess the efficacy and safety of HIFU in both primary treatment of men with localised and locally advanced prostate cancer as well as salvage treatment of men with recurrent prostate cancer following treatment failure of radical prostatectomy or external-beam radiation therapy.

Evidence acquisition

We conducted a systematic literature search for studies conducted on humans and published in either English or German in several databases from 2000 to 2010. In addition, we screened several Web sites for assessments on HIFU in prostate cancer and contacted the manufacturers of the two currently available HIFU devices for supplemental information on HIFU. We included all prospective studies with >50 study participants and assessed their quality using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Evidence synthesis

We identified 20 uncontrolled prospective case series, each of which treated between 58 and 517 patients. These studies were all conducted within the past decade. In total, 3018 patients were treated with HIFU, 93% for primary therapy and 7% for salvage HIFU. For all HIFU procedures, the biochemical disease-free survival rate at 1, 5, and 7 yr, respectively, was 78–84%, 45–84%, and 69%. The negative biopsy rate was 86% at 3 mo and 80% at 15 mo. Overall survival rates and prostate cancer–specific survival rates were 90% and 100% at 5 yr and 83% and 98% at 8 yr, respectively. Adverse events concerned the urinary tract (1–58%), potency (1–77%), the rectum (0–15%), and pain (1–6%). Quality-of-life assessment yielded controversial results.

Conclusions

Applying the GRADE approach, the available evidence on efficacy and safety of HIFU in prostate cancer is of very low quality, mainly due to study designs that lack control groups. More research is needed to explore the use of HIFU in prostate cancer.     

Prostate Cancer Tumour Features on Template Prostate-mapping Biopsies: Implications for Focal Therapy

Background

Focal therapy is being offered as a viable alternative for men with localised prostate cancer (PCa), but it is unclear which men may be suitable.

Objective

To determine the proportion of men with localised PCa who are potentially suitable for focal therapy.

Design, setting, and participants

Our institutional transperineal template prostate-mapping (TTPM) biopsy registry of 377 men from 2006 to 2010 identified 291 consecutive men with no prior treatment.

Intervention

TTPM biopsies using a 5-mm sampling frame.

Outcome measurements and statistical analysis

Suitability for focal therapy required the cancer to be (1) unifocal, (2) unilateral, (3) bilateral/bifocal with at least one neurovascular bundle avoided, or (4) bilateral/multifocal with one dominant index lesion and secondary lesions with Gleason ≤3 + 3 and cancer core involvement ≤3 mm. Binary logistic regression modelling was used to determine variables predictive for focal therapy suitability.

Results and limitations

The median age was 61 yr, and the median prostate-specific antigen was 6.8 ng/ml. The median total was 29 cores, with a median of 8 positive cores. Of 239 of 291 men with cancer, 29% (70 men), 60% (144 men), and 8% (20 men) had low-, intermediate-, and high-risk PCa, respectively. Ninety-two percent (220 men) were suitable for one form of focal therapy: hemiablation (22%, 53 men), unifocal ablation (31%, 73 men), bilateral/bifocal ablation (14%, 33 men), and index lesion ablation (26%, 61 men). Binary logistic regression modelling incorporating transrectal biopsy parameters showed no statistically significant predictive variable. When incorporating TTPM parameters, only T stage was a significant negative predictor for suitability (p = 0.001) (odds ratio: 0.001 [95% confidence interval, 0.000–0.048]). Limitations of the study include potential selection bias caused by tertiary referral practise and lack of long-term results on focal therapy efficacy.

Conclusions

Focal therapy requires an accurate tool to localise individual cancer lesions. When such a test, TTPM biopsy, was applied to men with low- and intermediate-risk PCa, most of the men were suitable for a tissue preservation strategy.     

Long-term Prostate-specific Antigen Velocity in Improved Classification of Prostate Cancer Risk and Mortality

Background

It remains unclear whether adding long-term prostate-specific antigen velocity (PSAV) to baseline PSA values improves classification of prostate cancer (PCa) risk and mortality in the general population.

Objective

To determine whether long-term PSAV improves classification of PCa risk and mortality in the general population.

Design, setting, and participants

We studied 503 men aged 30–80 yr, with and without PCa, who had repeated PSA measurements over 20 yr and up to 28 yr before PCa diagnosis. These were selected from among 7455 men in the Copenhagen City Heart Study, a prospective, general population study with follow-up from 1981 through 2010. Results were subsequently applied to all 1 351 441 men aged 40–80 yr living in Denmark from 1997 through 2006.

Outcome measurements and statistical analysis

PCa risk and mortality were assessed using Cox regression. Improvement in risk classification was assessed using the net reclassification index (NRI).

Results

Age-adjusted hazard ratios for PCa risk and mortality were 2.7–5.3 and 2.3–3.4, respectively, for long-term PSAV when added to models already including baseline PSA values. For PCa risk and mortality, adding long-term PSAV to models already including baseline PSA values and age yielded continuous NRIs of 98–99% and 56–106%, respectively. Used on a nationwide scale (eg, for men aged 60–64 yr), long-term PSAV >0.35 versus ≤0.35 ng/ml per year appropriately reclassified 128 of 10 000 men with PCa and 8095 of 10 000 men with no PCa. Correspondingly, inappropriately reclassified were 49 of 10 000 men with PCa and 1658 of 10 000 men with no PCa.

Conclusions

Long-term PSAV in addition to baseline PSA value improves classification of PCa risk and mortality. Applying long-term PSAV nationwide, the ratio of appropriately to inappropriately classified men would typically be 5:1.