Impact of 5α-reductase inhibitors on men followed by active surveillance for prostate cancer

Nonsurgical Interventions to Prevent Disease Progression in Prostate Cancer Patients on Active Surveillance: A Systematic Review and Meta-analysis

CONTEXT

Active surveillance (AS) is a standard of care for patients with low-risk and selected intermediate-risk prostate cancer (PCa). Nevertheless, there is a lack of summary evidence on how to impact disease trajectory during AS.

OBJECTIVE

To assess which interventions prevent PCa progression effectively during AS.

EVIDENCE ACQUISITION

We queried PubMed, Scopus, and Web of Science databases to identify studies examining the impact of interventions aimed at slowing disease progression during AS. The primary endpoint was PCa progression, the definition of which must have included pathological upgrading. The secondary endpoint included treatment toxicities.

EVIDENCE SYNTHESIS

We identified 22 studies, six randomized controlled trials and 16 observational studies, which analyzed the association between different interventions and PCa progression during AS. The interventions considered in the studies included 5-alpha reductase inhibitors (5-ARIs), statins, diet, exercise, chlormadinone, fexapotide triflutate (FT), enzalutamide, coffee, vitamin D3, and PROSTVAC. We found that administration of 5-ARIs was associated with improved progression-free survival (PFS; hazard ratio: 0.59; 95% confidence interval 0.48-0.72), with no increased toxicity signals. Therapies such as vitamin D3, chlormadinone, FT, and enzalutamide have shown some efficacy. However, these anticancer drugs have been associated with treatment-related adverse events in up to 88% of patients.

CONCLUSIONS

The use of 5-ARIs in PCa patients on AS is associated with longer PFS. However, for the other interventions, it is difficult to draw clear conclusions based on the weak available evidence.

PATIENT SUMMARY

Patients with prostate cancer managed with active surveillance (AS) who are treated with 5-alpha reductase inhibitors have a lower risk of disease progression, with minimal adverse events. Other interventions require more studies to determine their efficacy and safety profile in men on AS.

Five-alpha reductase inhibitors in men undergoing active surveillance for prostate cancer: impact on treatment and reclassification after 6 years follow-up

OBJECTIVES

To evaluate the impact of 5-alpha reductase inhibitors (5-ARIs) on definitive treatment (DT) and pathological progression (PP) in patients on active surveillance (AS) for prostate cancer.

METHODS

We identified 361 consecutive patients, from an IRB-approved database, on AS for prostate cancer with minimum 2 years follow-up. Patients were grouped into two cohorts, those using 5-ARIs (5-ARI; n = 119) or not using 5-ARIs (no 5-ARI; n = 242). Primary and secondary endpoints were treatment-free survival (TFS) and PP-free survival (PPFS), which were evaluated by Kaplan-Meier analysis. Univariate and multivariable cox regression analysis were used to identify predictors for PP and DT. A p value < 0.05 was considered statistically significant.

RESULTS

Baseline characteristics and the prostate biopsy rate were similar between the two groups. Median (range) follow-up was 5.7 (2.0-17.2) years. Five-year and 10-year TFS was 92% and 59% for the 5-ARI group versus 80% and 51% for the no 5-ARI group (p = 0.005), respectively. Five-year and 10-year PPFS was 77% and 41% for the 5-ARI group versus 70% and 32% for the no 5-ARI group (p = 0.04), respectively. Independent predictors for treatment and PP were not taking 5-ARIs (p = 0.005; p = 0.02), entry PSA > 2.5 ng/mL (p = 0.03; p = 0.01) and Gleason pattern 4 on initial biopsy (p < 0.001; p < 0.001), respectively. The main limitation is the retrospective study design.

CONCLUSIONS

5-ARIs reduces reclassification and cross-over to treatment in men on active surveillance for prostate cancer. Further, taking 5-ARIs was an independent predictor for prostate cancer progression and definitive treatment.

Prostate cancer patients can benefit from 5-alpha-reductase inhibitor treatment: a meta-analysis

Background

The efficacy and safety of 5α-reductase inhibitors (5ARIs) in treating prostate cancer (PCa) have not been fully determined. We performed a meta-analysis to evaluate the effectiveness and safety of 5ARIs for PCa patients.

Methods

A comprehensive literature search of online databases was conducted to obtain comparative studies exploring the effectiveness and safety of 5ARIs in treating PCa up to October 2019. Summarized odds ratio s (OR s) or hazard ratio s (HR s) were calculated to compare the outcomes between 5ARI and control groups. Our meta-analysis was registered in PROSPERO under number CRD42018109809.

Results

A total of 2,277 patients from 10 studies were included. No significant difference was found in prostate-specific antigen progression between two groups (OR = 0.82, 95% CI [0.52–1.29], P = 0.40). However, 5ARI treatment significantly reduced the total progression of PCa (OR = 0.61, 95% CI [0.48–0.77], P < 0.0001), especially for patients with local (OR = 0.56, 95% CI [0.44–0.73], P < 0.00001) and low-Gleason score (≤7) PCa (OR = 0.63, 95% CI [0.48–0.84], P = 0.002). Additionally, 5ARIs also significantly prolonged the progression-free survival time (HR = 0.57, 95% CI [0.34–0.96], P = 0.04) for PCa patients. No significant difference was found in the occurrence of PCa recurrence, metastasis, biopsy reclassification, and side-effects between two groups.

Conclusions

Our study suggests that 5ARI treatment can benefit patients with local and low Gleason score (≤7) PCa, especially in delaying the disease progression. More studies with larger sample size and comprehensive study design are still needed to verify our outcomes.

Long-term use of 5-alpha-reductase inhibitors is safe and effective in men on active surveillance for prostate cancer

BACKGROUND

Although 5-alpha-reductase inhibitors (5ARIs) have been shown to benefit men with prostate cancer (PCa) on active surveillance (AS), their long-term safety remains controversial. Our objective is to describe the long-term association of 5ARI use with PCa progression in men on AS.

MATERIALS/SUBJECTS AND METHODS

The cohort of men with low-risk PCa was derived from a prospectively maintained AS database at the Princess Margaret (1995-2016). Pathologic, grade, and volume progression were the primary end points. Kaplan-Meier time-to-event analysis was performed and Cox proportional hazards regression was used to determine predictors of progression where 5ARI exposure was analyzed as a time-dependent variable. Patients who came off AS prior to any progression events were censored at that time.

RESULTS

The cohort included 288 men with median follow-up of 82 months (interquartile range: 37-120 months). Among non-5ARI users (n = 203); 114 men (56.2%) experienced pathologic progression compared with 24 men (28.2%) in the 5ARI group (n = 85), (p < 0.001). Grade and volume progression were higher in the non-5ARI group compared with the 5ARI group (n = 82; 40.4% vs. n = 19; 22.4% respectively, p = 0.003 for grade progression; n = 87; 43.1% and n = 15; 17.7%, respectively for volume progression p < 0.001). Lack of 5ARI use was independently positively associated with pathologic progression (HR: 2.65; CI: 1.65-4.24), grade progression (HR: 2.75; CI: 1.49-5.06), and volume progression (HR: 3.15; CI: 1.78-5.56). The frequency of progression to high-grade (Grade Group 4-5) tumors was not significantly different between the groups.

CONCLUSIONS

Use of 5ARIs diminished both grade and volume progression without an increased risk of developing Grade Groups 4-5 disease.

Association between 5α-reductase inhibitors therapy and incidence, cancer-specific mortality, and progression of prostate cancer: evidence from a meta-analysis

5α-reductase inhibitors (5-ARI) are widely employed for the treatment of benign prostatic hyperplasia. It has been noted that 5-ARI exhibit the potential to attenuate the risk of prostate cancer, but consistent agreement has not been achieved. Moreover, the effect of 5-ARI on cancer-specific mortality and progression of prostate cancer remains unclear. Therefore, the goal of the current meta-analysis was to elucidate the impact of 5-ARI on the incidence and progression of prostate cancer. We searched for all studies assessing the effect of 5-ARI on risk of prostate cancer in PubMed, Embase, Medline, and Cochrane Library databases. Pooled relative risk (RR) and corresponding 95% confidence intervals (CIs) were accepted to evaluate the association between 5-ARI and the risk of prostate cancer. Synthetic results implied that subjects who accepted 5-ARI compared with the placebo group experienced a distinctly weakened overall incidence of prostate cancer (RR = 0.74; 95% CI: 0.66–0.82; P < 0.001). Subgroup analyses further revealed that 5-ARI reduction of the incidence of prostate cancer was limited to low-grade (Gleason score 2–6; RR = 0.68; 95% CI: 0.57–0.81; P < 0.001) and intermediate-grade tumors (Gleason score 7; RR = 0.81; 95% CI: 0.67–0.97; P = 0.023), but not high-grade tumors (Gleason score >7; RR = 1.19; 95% CI: 0.98–1.43; P = 0.069). The results also showed that 5-ARI treatment did not significantly alter prostate cancer-specific mortality (RR = 1.0; 95% CI: 0.95–1.05; P = 0.916). In addition, it was worth noting that 5-ARI treatment acted in a protective role that presented a dramatic benefit to delay the progression of low-risk tumors (RR = 0.58; 95% CI: 0.43–0.78; P < 0.001).

Active surveillance review: contemporary selection criteria, follow-up, compliance and outcomes

The primary goal of active surveillance (AS) is to prevent overtreatment by selecting patients with low-risk prostate cancer (PCa) and closely monitoring them so that definitive treatment can be offered when needed. With the increasing popularity of AS as a management strategy for men with localized PCa, it is important to understand all the contemporary guidelines and criteria that exist for AS and the differences among them. No single optimal management strategy for clinically localized, early-stage disease has been universally accepted. The implementation of AS varies widely between institutions, from inclusion criteria to follow-up protocols, with the most notable differences seen in maximum accepted Gleason score, T-stage and prostate-specific antigen (PSA) parameters. The objectives of this review were to systematically summarize the current literature on AS strategy, present an overview of the various published guidelines and criteria that are used for AS at several major institutions as well as discuss goals and trade-offs of the various criteria. A comprehensive search of the PubMed and Embase databases from 1990 to 2017 was performed to identify studies pertaining to AS criteria and trends. Trends in AS uptake and use in Canada, USA and Europe were reviewed to demonstrate the current trends and outcomes of AS to offer greater insight into the differences, nature and efficacy of various AS protocols. AS is a compelling antidote to the current PCa overtreatment phenomena; however, when considering patients for AS it is important to understand the differences between protocols, and review published results to appreciate the impact on follow-up.

Prognostic influence of 5 alpha reductase inhibitors in patients with localized prostate cancer under active surveillance

Objective

The incidence of prostate adenocarcinoma (PCa) is increased with the use of prostate-specific antigen (PSA). In the current study, we aimed to investigate the impact of 5- alpha- reductase inhibitors (5-ARI) on pathological progression in patients followed by active surveillance (AS).

Material and methods

Records of 69 patients with localized prostate cancer under AS (PSA ≤15 ng/mL, PSAD ≤0.20, ≤cT2c, Gleason sum ≤3+3, the number of cancer positive cores ≤3) were evaluated retrospectively. Patients were followed-up with quarterly PSA testing and semiannual digital rectal examination during the first 2 years, and semiannual PSA testing thereafter. Repeat biopsies were done annually and whenever indicated by clinical findings. Pathological progression was defined as increasing Gleason grade, number of cancer-positive cores, and/or increasing percentage of cancer in any core.

Results

Patients using (29/69: 42%) and not using (40/69: 58%) 5-ARI were followed for a median of 39 (IQR: 23-45) and 23.5 (IQR: 17-37.5) months, respectively. Pathological progression was observed in 32% (22/69) of the patients at a median of 25 (IQR: 18-39) months. Pathological progression was observed in 34.5% (10/29) and 30% (12/40) of the patients using and not using 5-ARI, respectively (Log-rank p=0.4151). Definitive treatment was done in 31% (9/29) and 47.5% (19/40) of the patients using and not using 5-ARI, respectively. Patients who did not use 5-ARI received definitive treatment earlier than 5-ARI users (Log-rank p=0.0342). On multivariate analysis, more than 2 cancer-positive cores (HR: 11.62) and age (HR: 0.94) were independently associated with pathological progression (p<0.05), rather than 5-ARI use (p=0.148).

Conclusion

More than 2 cancer- positive cores at the initial biopsy was the strongest covariate associated with pathological progression; these patients should not be offered AS. There was no impact of 5-ARI use on pathological progression in AS.

Prognostic value of urinary prostate cancer antigen 3 (PCA3) during active surveillance of patients with low-risk prostate cancer receiving 5α-reductase inhibitors

OBJECTIVES

To determine the clinical performance of the urinary prostate cancer antigen 3 (PCA3) test to predict the risk of Gleason grade re-classification amongst men receiving a 5α-reductase inhibitor (5ARI) during active surveillance (AS) for prostate cancer.

PATIENTS AND METHODS

Patients with low-risk prostate cancer were enrolled in a prospective Phase II study of AS complemented with prescription of a 5ARI. A repeat biopsy was taken within the first year and annually according to physician and patient preference. In all, 90 patients had urine collected after digital rectal examination of the prostate before the first repeat biopsy. The PCA3 test was performed in a blinded manner at a central laboratory.

RESULTS

Using a PCA3-test score threshold of 35, there was a significant difference (P < 0.001) in the risk of being diagnosed with Gleason ≥7 cancer during a median of 7 years of follow-up. Adjusted Cox regression and Kaplan-Meier analyses also showed a significantly higher risk of upgrading to Gleason ≥7 during follow-up for those with a higher PCA3-test score.

CONCLUSION

The urinary PCA3 test predicted Gleason grade re-classification amongst patients receiving a 5ARI during AS for low-risk prostate cancer.

Preventing clinical progression and need for treatment in patients on active surveillance for prostate cancer

PURPOSE OF REVIEW

Active surveillance is an established treatment option for men with localized, low-risk prostate cancer (CaP). It entails the postponement of immediate therapy with the option of delayed intervention upon disease progression. The rate of clinical progression and need for treatment on active surveillance is approximately 50% over 15 years. The present review summarizes recent data on current methods, attempting to prevent clinical progression.

RECENT FINDINGS

Patient selection for active surveillance is the first mandatory step required to lower progression. Adherence to active surveillance protocols is critical in making sure patients are monitored well and treated early when progression occurs. Before active surveillance allocation and during active surveillance follow-up, methods involving multiparametric MRI, prostate specific antigen derivatives, biopsy factors, urinary, tissue and genetic markers can be used to prevent clinical progression and/or identify those at risk for progression. Medications such as 5α-reductase inhibitors and others might inhibit disease progression in patients on active surveillance.

SUMMARY

Active surveillance is required because of overdiagnosis, along with our inability to accurately predict individual CaP behavior. Several methods can potentially reduce the risk of CaP progression in patients with active surveillance. However, a measure of uncertainty and fear of progression will always accompany patients with active surveillance and the physicians treating them.

Co-clinical Analysis of a Genetically Engineered Mouse Model and Human Prostate Cancer Reveals Significance of NKX3.1 Expression for Response to 5α-reductase Inhibition

BACKGROUND

Although men on active surveillance for prostate cancer (PCa) may benefit from intervention with 5α-reductase inhibitors (5-ARIs), it has not been resolved whether 5-ARIs are effective for delaying disease progression and, if so, whether specific patients are more likely to benefit.

OBJECTIVE

To identify molecular features predictive of patient response to 5-ARIs.

DESIGN, SETTING, AND PARTICIPANTS

Nkx3.1 mutant mice, a model of early-stage PCa, were treated with the 5-ARI finasteride, and histopathological and molecular analyses were performed. Cross-species computational analyses were used to compare expression profiles for treated mice with those of patients who had received 5-ARIs before prostatectomy.

INTERVENTION

Finasteride administered to Nkx3.1 mutant mice. 5-ARI-treated patient specimens obtained retrospectively.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Endpoints in mice included histopathology, immunohistochemistry, and molecular profiling. GraphPad Prism software, R-studio, and Matlab were used for statistical and data analyses.

RESULTS AND LIMITATIONS

Finasteride treatment of Nkx3.1 mutant mice resulted in a significant reduction in prostatic intraepithelial neoplasia (PIN), as evident from histopathological and expression profiling analyses. Cross-species computational analysis comparing finasteride-treated mice with two independent 5-ARI-treated patient cohorts showed that reduced NKX3.1 expression is predictive of response to 5-ARI. A limitation of the study is that these retrospective human cohorts have relatively few patients with limited clinical outcome data. Future prospective clinical trials are needed to validate whether stratifying patients on the basis of NKX3.1 expression improves the benefit of 5-ARIs during active surveillance.

CONCLUSIONS

This co-clinical study implicates NKX3.1 status as a predictor of response to 5-ARIs, and suggests that molecular features, including NKX3.1 expression, may help to identify PCa patients most likely to benefit from 5-ARIs during active surveillance.

PATIENT SUMMARY

The aim of precision cancer prevention is to tailor interventions on the basis of individualized patient characteristics. We propose that patients with low NKX3.1 expression are optimal candidates for intervention with 5α-reductase inhibitors as an adjunct to active surveillance.

The Relationship Between Metformin and Serum Prostate-Specific Antigen Levels

BACKGROUND

Metformin is the first-line oral antihyperglycemic of choice for individuals with type 2 diabetes. Recent evidence supports a role for metformin in prostate cancer chemoprotection. However, whether metformin indeed influences prostate biology is unknown. We aimed to study the association between metformin and serum prostate-specific antigen (PSA) levels-the primary prostate cancer biomarker.

METHODS

We conducted a cross-sectional study of 326 prostate cancer-free men with type 2 diabetes were recruited between 2004 and 2013 at St. Michael's Hospital. Men were excluded if they had a PSA ≥10-ng/ml, or used >2,550-mg/d metformin or supplemental androgens. Multivariate linear regressions quantified the association between metformin dose and log-PSA. Secondary analyses quantified the association between other antihyperglycemics (sulfonylureas, thiazolidinediones) and PSA; sensitivity analyses tested covariate interactions.

RESULTS

Median PSA was 0.9-ng/ml (IQR: 0.5-1.6-ng/ml). Metformin dose associated positively with BMI, HbA1c, diabetes duration, and number of statin, acetylsalicylic acid, diuretic users, and number of antihyperglycemics used, and negatively with LDL-C. In multivariate models, PSA changed by -8% (95%CI: -13 to -2%, P = 0.011) per 500-mg/d increase in metformin. Men with diabetes for ≥6 years (n = 163) saw a greater difference in PSA per 500-mg/d metformin (-12% [95% CI: -19 to -4%, P = 0.002], P-interaction = 0.018). Serum PSA did not relate with sulfonylureas, thiazolidinediones, or total number of antihyperglycemic agents used. Our findings are limited by the cross-sectional design of this study.

CONCLUSIONS

Metformin dose-dependently inversely associated with serum PSA, independent of other antihyperglycemic medications. Whether metformin confers a dose-dependent benefit on prostate tumorigenesis and progression warrants investigation. Prostate 76:1445-1453, 2016. © 2016 The Authors. The Prostate published by Wiley Periodicals, Inc.

Active surveillance for the management of localized prostate cancer: Guideline recommendations

INTRODUCTION

The objective is to provide guidance on the role of active surveillance (AS) as a management strategy for low-risk prostate cancer patients and to ensure that AS is offered to appropriate patients assessed by a standardized protocol. Prostate cancer is often a slowly progressive or sometimes non-progressive indolent disease diagnosed at an early stage with localized tumours that are unlikely to cause morbidity or death. Standard active treatments for prostate cancer include radiotherapy (RT) or radical prostatectomy (RP), but the harms from over diagnosis and overtreatment are of a significant concern. AS is increasingly being considered as a management strategy to avoid or delay the potential harms caused by unnecessary radical treatment.

METHODS

A literature search of MEDLINE, EMBASE, the Cochrane library, guideline databases and relevant meeting proceedings was performed and a systematic review of identified evidence was synthesized to make recommendations relating to the role of AS in the management of localized prostate cancer.

RESULTS

No exiting guidelines or reviews were suitable for use in the synthesis of evidence for the recommendations, but 59 reports of primary studies were identified. Due to studies being either non-comparative or heterogeneous, pooled meta-analyses were not conducted.

CONCLUSION

The working group concluded that for patients with low-risk (Gleason score ≤6) localized prostate cancer, AS is the preferred disease management strategy. Active treatment (RP or RT) is appropriate for patients with intermediate-risk (Gleason score 7) localized prostate cancer. For select patients with low-volume Gleason 3+4=7 localized prostate cancer, AS can be considered.

Active surveillance for low-risk prostate cancer

Overtreatment of prostate cancer has become evident as studies comparing radical prostatectomy vs watchful waiting have shown that radical treatment benefits only a proportion of patients. Active surveillance was introduced as a management option for prostate cancer at low-risk of progression with the aim to closely observe for disease progression or change of tumour characteristics and offer active treatment if and when necessary. Active surveillance has been reserved for patients with Gleason 6 localised disease and low PSA; however, selection criteria may be widened as intermediate-term outcomes demonstrate excellent safety, efficacy and patient acceptance.

Expectant management for men with early stage prostate cancer

Since the dissemination of prostate-specific antigen screening, most men with prostate cancer are now diagnosed with localized, low-risk prostate cancer that is unlikely to be lethal. Nevertheless, nearly all of these men undergo primary treatment with surgery or radiation, placing them at risk for longstanding side effects, including erectile dysfunction and impaired urinary function. Active surveillance and other observational strategies (ie, expectant management) have produced excellent long-term disease-specific survival and minimal morbidity for men with prostate cancer. Despite this, expectant management remains underused for men with localized prostate cancer. In this review, various approaches to the expectant management of men with prostate cancer are summarized, including watchful waiting and active surveillance strategies. Contemporary cancer-specific and health care quality-of-life outcomes are described for each of these approaches. Finally, contemporary patterns of use, potential disparities in care, and ongoing research and controversies surrounding expectant management of men with localized prostate cancer are discussed.

Differences among men on active surveillance for very low-risk prostate cancer detected through population-based versus opportunistic prostate-specific antigen-screening

INTRODUCTION

Very low-risk prostate cancer (PCa) is being increasingly managed by active surveillance (AS). Our aim was to assess the influence of the origin of diagnosis on PCa characteristics and treatment rates among men with very low-risk PCa in our prospective AS cohort.

METHODS

Overall, 191 men with very low-risk PCa fulfilling Epstein-criteria underwent protocol-based AS. These men originated either from the prospective population-based screening program (P-AS) or were diagnosed by opportunistic screening (O-AS).

RESULTS

Overall, n = 86 (45.0%) originated from the P-AS group, whereas n = 105 (55.0%) from the O-AS group. On univariate Cox regression analysis, age (HR 0.96, 95% CI 0.92-1.00; p = 0.05), origin of diagnosis (HR 0.72, 95% CI 0.41-1.28; p = 0.001), number of positive cores (HR 2.15, 95% CI 1.18-3.90; p = 0.01) and maximum core involvement (HR 1.03, 95% CI 0.99-1.05; p = 0.05) were predictors for treatment necessity. On multivariate analysis, age (HR 0.95, 95% CI 0.89-0.99; p = 0.05), number of positive cores (HR 2.07, 95% CI 1.10-3.88; p = 0.02), maximum core involvement (HR 1.03, 95% CI 1.00-1.06; p = 0.04) but not origin of diagnosis were independent predictors for treatment necessity. Four men developed biochemical recurrence (all from O-AS group [p = 0.05]).

CONCLUSION

The origin of PCa diagnosis in men undergoing AS had no influence on disease progression and treatment necessity.

5-Alpha reductase inhibitors in active surveillance

PURPOSE OF REVIEW

Active surveillance is now one of the recommended treatment options for low-risk prostate cancer (PCa). However, about 10-30% of men on active surveillance will progress and require definitive therapy. In this review, we examine the role of 5-alpha reductase inhibitors (5-ARIs) in secondary prevention among men with low-risk PCa who opted to be managed by active surveillance.

RECENT FINDINGS

Three retrospective studies and one randomized controlled trial have evaluated the role of 5-ARIs in preventing clinical progression among men followed by active surveillance. These studies largely support the role of 5-ARIs for secondary chemoprevention, although the drugs do not have an indication for this setting.

SUMMARY

5-ARIs have been shown to play an important role in preventing clinical progression among men with low-risk PCa on active surveillance. However, in light of the US Food and Drug Administration recommendation against 5-ARIs for primary chemoprevention, these findings should be interpreted with caution. Patients should be made aware of this warning label before starting the drug.

5-Alpha-reductase inhibitors in diseases of the prostate

PURPOSE OF REVIEW

To summarize the history of the use of 5-alpha-reductase inhibitors in the treatment of urologic diseases and discuss the current practices and indications for therapy.

RECENT FINDINGS

5-Alpha-reductase inhibitors (5-ARIs) are indicated in the treatment of benign prostatic hyperplasia (BPH) with obstructive urinary symptoms to reduce symptoms, reduce the risk of acute urinary retention, and reduce the risk of needing surgical management for this condition. These drugs have also been employed in the treatment of recurrent and refractory hematuria of prostatic origin because of their effect on the androgen-mediated angiogenic pathways in the prostate. Data support the use of 5-ARIs for this indication, though this is off-label use. There is no role for the use of 5-ARIs in primary prostate cancer chemoprevention and they may increase the risk of developing high-grade prostate cancer. Current investigations are underway to determine the efficacy of 5-ARIs in the secondary treatment of localized prostate cancer as adjunctive therapy, which may decrease the likelihood of prostate cancer progression and increase the likelihood that patients will remain on active surveillance.

SUMMARY

5-ARIs have significantly impacted the medical treatment of urologic disease, in particular BPH, and prostatic hematuria. Their use in the secondary treatment of prostate cancer is currently under investigation.

Active surveillance in patients with a PSA >10 ng/mL

INTRODUCTION

The use of prostate-specific antigen (PSA) in active surveillance (AS) for prostate cancer is controversial. Some consider it an unreliable marker and others as sufficient evidence to exclude patients from AS. We analyzed our cohort of AS patients with a PSA over 10 ng/mL.

METHODS

We included patients who had clinical T1c-T2a Gleason ≤6 disease, and ≤3 positive cores with ≤50% core involvement at diagnostic biopsy and ≥2 total biopsies. Patients were divided into 3 groups: (1) those with baseline PSA >10 ng/mL, (2) those with a PSA rise >10 ng/mL during follow-up; and (3) those with a PSA <10 ng/mL throughout AS. Adverse histology was defined as biopsy parameters exceeding the entry criteria limits. We further compared this cohort to a concurrent institutional cohort with equal biopsy parameters treated with immediate radical prostatectomy.

RESULTS

Our cohort included 698 patients with a median follow-up of 46.2 months. In total, 82 patients had a baseline PSA >10 ng/mL and 157 had a PSA rise >10 ng/mL during surveillance. No difference in adverse histology incidence was detected between groups (p = 0.3). Patients with a PSA greater than 10 were older and had higher prostate volumes. Hazard ratios for groups with a PSA >10 were protective against adverse histology. Larger prostate volume and minimal core involvement appear as factors related to this successful selection of patients to be treated with AS.

CONCLUSION

These results suggest that a strict cut-off PSA value for all AS patients is unwarranted and may result in overtreatment. Though lacking long-term data and validation, AS appears safe in select patients with a PSA >10 ng/mL and low volume Gleason 6 disease.

5α-Reductase inhibitors and risk of high-grade or lethal prostate cancer

IMPORTANCE

5α-Reductase inhibitors (5ARIs) are widely used for benign prostatic hyperplasia despite controversy regarding potential risk of high-grade prostate cancer with use. Furthermore, the effect of 5ARIs on progression and prostate cancer death remains unclear.

OBJECTIVE

To determine the association between 5ARI use and development of high-grade or lethal prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational study of 38,058 men followed up for prostate cancer diagnosis and outcomes between 1996 and 2010 in the Health Professionals Follow-up Study.

EXPOSURES

Use of 5ARIs between 1996 and 2010.

MAIN OUTCOMES AND MEASURES

Cox proportional hazards models were used to estimate risk of prostate cancer diagnosis or development of lethal disease with 5ARI use, adjusting for possible confounders including prostate specific antigen testing.

RESULTS

During 448,803 person-years of follow-up, we ascertained 3681 incident prostate cancer cases. Of these, 289 were lethal (metastatic or fatal), 456 were high grade (Gleason sum [GS] 8-10), 1238 were GS 7, and 1600 were low grade (GS 2-6). A total of 2878 (7.6%) men reported use of 5ARIs between 1996 and 2010. After adjusting for confounders, men who reported ever using 5ARIs over the study period had a reduced risk of overall prostate cancer (hazard ratio [HR], 0.77; 95% CI, 0.65-0.91). 5ARI users had a reduced risk of GS 7 (HR, 0.67; 95% CI, 0.49-0.91) and low-grade (GS 2-6) prostate cancer (HR, 0.74; 95% CI, 0.57-0.95). 5ARI use was not associated with risk of high-grade (GS 8-10) prostate cancer (HR, 0.97; 95% CI, 0.64-1.46) or lethal disease (HR, 0.99; 95% CI, 0.58-1.69). Increased duration of use was associated with significantly lower risk of overall prostate cancer (HR for 1 year of additional use, 0.95; 95% CI, 0.92-0.99), localized (HR, 0.95; 95% CI, 0.90-1.00), and low-grade disease (HR, 0.92; 95% CI, 0.85-0.99). There was no association for lethal, high-grade, or grade 7 disease.

CONCLUSIONS AND RELEVANCE

While 5ARI use was not associated with developing high-grade or lethal prostate cancer, it was associated with a reduction in low-grade, GS 7, and overall prostate cancer. Because the number of patients with high-grade or lethal prostate cancer in our cohort was limited, we cannot rule out potential risk of harm with 5ARI use.

Advances in prostate cancer chemoprevention: a translational perspective

Chemopreventive interventions are steadily emerging as an important aspect of cancer management and control. Herein, we have discussed the major epidemiological and clinical studies advocating the role of androgen inhibitors, flavonoids and antioxidants in preventing prostate cancer (PCa). Androgen inhibitors have lately been discussed not only in treatment of PCa, but also as preventive agents especially after trials with Finasteride and Dutasteride. Flavonoids such as silibinin, green tea polyphenols, genistein, curcumin have shown great promise, but avenues to improve their bioavailability are requisite. Agents with antioxidant potentials like lycopene, selenium, and vitamin E have also been explored. Antioxidant trials have yielded mixed results or benefitted only a subgroup of population, although further studies are needed to establish them as preventive agent. Although a majority of the trials resulted in positive outcomes supporting their role as preventive agents; one should be cautious of neutral or negative results as well. For clinical applicability of these agents, we need to identify the ideal target population, time of intervention, appropriate dosage, and extent of intervention required. Incoherency of data with these agents urges for a stringent study design and thorough interpretation to accurately judge the necessity and feasibility of the preventive measures.

The Study of Active Monitoring in Sweden (SAMS): a randomized study comparing two different follow-up schedules for active surveillance of low-risk prostate cancer

OBJECTIVE

Only a minority of patients with low-risk prostate cancer needs treatment, but the methods for optimal selection of patients for treatment are not established. This article describes the Study of Active Monitoring in Sweden (SAMS), which aims to improve those methods.

MATERIAL AND METHODS

SAMS is a prospective, multicentre study of active surveillance for low-risk prostate cancer. It consists of a randomized part comparing standard rebiopsy and follow-up with an extensive initial rebiopsy coupled with less intensive follow-up and no further scheduled biopsies (SAMS-FU), as well as an observational part (SAMS-ObsQoL). Quality of life is assessed with questionnaires and compared with patients receiving primary curative treatment. SAMS-FU is planned to randomize 500 patients and SAMS-ObsQoL to include at least 500 patients during 5 years. The primary endpoint is conversion to active treatment. The secondary endpoints include symptoms, distant metastases and mortality. All patients will be followed for 10-15 years.

RESULTS

Inclusion started in October 2011. In March 2013, 148 patients were included at 13 Swedish urological centres.

CONCLUSIONS

It is hoped that the results of SAMS will contribute to fewer patients with indolent, low-risk prostate cancer receiving unnecessary treatment and more patients on active surveillance who need treatment receiving it when the disease is still curable. The less intensive investigational follow-up in the SAMS-FU trial would reduce the healthcare resources allocated to this large group of patients if it replaced the present standard schedule.

5-alpha reductase inhibitors in patients on active surveillance: do the benefits outweigh the risk?

Prostate cancer (PCa) is a slow, progressive disease. Prostate specific antigen testing, screening, and aggressive case identification has made PCa the most frequently diagnosed cancer. Concerns regarding overdiagnosis and overtreatment flourish on a large scale. In order to avoid overtreatment for those in whom therapeutic intervention is not required, active surveillance for eligible patients with the use of 5-alpha reductase can be considered a safe and a promising approach to delay the progression of the disease with minimal side effects.

The current status of active surveillance for prostate cancer

The occurrence of low-risk, localized prostate cancer (PCa) has increased in the prostate-specific antigen era. A significant amount of low-risk PCas progress slowly and may not impact patient survival. Thus, these patients may be subjected to unnecessary interventions that result in physical and psychological complications. The active surveillance (AS) protocol has been used over the few past decades. It was designed so that patients with low-risk PCa can be monitored for a period of time, during which they are free from complication of interventions, and can be treated with curative intention on evidence of disease progression. Institutions have developed different selection criteria and follow-up schedules for suitable patients with PCa. Recently, long-term data have emerged suggesting that AS is a reasonable option for appropriately selected patients with low-risk PCa who have a life expectancy of < 10 years. Subsequently, the AS protocol has been recognized by various guidelines as part of the treatment strategy for PCa. However, the challenges that remain for AS are the risk of under-staging of PCa and the low uptake and high attrition rate of AS, and questions remain regarding its long-term efficacy. Recent advances in AS for PCa, such as better imaging modality, combining AS with limited local therapy, as well as the role of AS in association with chemoprevention, are discussed.

Dutasteride in localised prostate cancer management: the REDEEM randomised, double-blind, placebo-controlled trial

BACKGROUND

We aimed to investigate the safety and efficacy of dutasteride, a 5α-reductase inhibitor, on prostate cancer progression in men with low-risk disease who chose to be followed up with active surveillance.

METHODS

In our 3 year, randomised, double-blind, placebo-controlled study, undertaken at 65 academic medical centres or outpatient clinics in North America, we enrolled men aged 48-82 years who had low-volume, Gleason score 5-6 prostate cancer and had chosen to be followed up with active surveillance. We randomly allocated participants in a one-to-one ratio, stratified by site and in block sizes of four, to receive once-daily dutasteride 0·5 mg or matching placebo. Participants were followed up for 3 years, with 12-core prostate biopsy samples obtained after 18 months and 3 years. The primary endpoint was time to prostate cancer progression, defined as the number of days between the start of study treatment and the earlier of either pathological progression (in patients with ≥1 biopsy assessment after baseline) or therapeutic progression (start of medical therapy). This trial is registered with ClinicalTrials.gov, number NCT00363311.

FINDINGS

Between Aug 10, 2006, and March 26, 2007, we randomly allocated 302 participants, of whom 289 (96%) had at least one biopsy procedure after baseline and were included in the primary analysis. By 3 years, 54 (38%) of 144 men in the dutasteride group and 70 (48%) of 145 controls had prostate cancer progression (pathological or therapeutic; hazard ratio 0·62, 95% CI 0·43-0·89; p=0·009). Incidence of adverse events was much the same between treatment groups. 35 (24%) men in the dutasteride group and 23 (15%) controls had sexual adverse events or breast enlargement or tenderness. Eight (5%) men in the dutasteride group and seven (5%) controls had cardiovascular adverse events, but there were no prostate cancer-related deaths or instances of metastatic disease.

INTERPRETATION

Dutasteride could provide a beneficial adjunct to active surveillance for men with low-risk prostate cancer.

FUNDING

GlaxoSmithKline.

Effect of treatment with 5-α reductase inhibitors on progression in monitored men with favourable-risk prostate cancer

What's known on the subject? and What does the study add? Finasteride (Proscar) and dutasteride (Avodart) are 5-α reductase inhibitors (5-ARIs) used to treat LUTS in men with benign prostatic enlargement. Because these drugs suppress androgens, the theory has been put forward that 5-ARIs might prevent the development of prostate cancer. Careful analysis of two randomized controlled trials, however, showed that, in the clinical setting, this was not the case, and that these drugs can increase the occurrence of more aggressive high-grade disease. Because of this, the U.S. Food and Drug Administration did not approve 5-ARIs for the primary prevention of prostate cancer and notified healthcare professionals about a change in the 'Warnings and Precautions' for these drugs. Interest remains among some for using 5-ARIs in men diagnosed with very low-risk prostate cancer to delay the progression from clinically indolent disease to clinically significant disease requiring treatment. The present study investigated whether 5-ARI use among men with very low-risk prostate cancer in an active surveillance (AS) programme would reduce the number of cancers reclassified to clinically significant disease on surveillance biopsy. Our results do not support the use of 5-ARIs for slowing or preventing cancer progression in men with low-risk prostate cancer, but do suggest that men with very low-risk prostate cancer who take 5-ARIs for LUTS are unlikely to be at increased risk for the development of high grade disease during AS.

OBJECTIVE

To determine whether 5-α reductase inhibitor (5-ARI) use delays cancer reclassification in an active surveillance (AS) cohort.

PATIENTS AND METHODS

We performed a retrospective study of 587 men enrolled in an AS programme, who had no history of 5-ARI use. Chi-squared and t-tests were used to compare characteristics of 5-ARI users and non-users. Univariable and multivariable proportional hazards models, treating 5-ARI use as a time-dependent covariate, were used to evaluate the influence of 5-ARIs on the risk of a subsequent biopsy no longer meeting criteria for continued AS (i.e. reclassification).

RESULTS

5-ARI use was initiated in 47 men while on AS. Men using 5-ARIs had larger prostates and higher PSA levels at diagnosis. During 5-ARI use, PSA levels and prostate volume deceased by mean values of 47% and 11%, respectively. Men using 5-ARIs had a mean of 2.5 surveillance biopsies while on the drug. Reclassification occurred in 17% of 5-ARI users compared with 31% of non-users (P = 0.04). Multivariable models (adjusting for age, α-blocker use, PSA level, %free PSA, PSA density, prostate volume and number/percent biopsy core involvement at diagnosis) showed nonsignificant risk reductions for reclassification in 5-ARI users as determined by either tumour extent (hazard ratio [HR] = 0.37 (95% confidence interval [CI] 0.12 to 1.13), P = 0.08) or grade (HR = 0.8 (95% CI 0.25-2.59), P = 0.7).

CONCLUSION

Treatment with 5-ARIs did not significantly alter the outcome of biopsy reclassification by grade in men with very low-risk prostate cancer.

Active surveillance for low-risk prostate cancer: an update

Active surveillance is now an accepted management strategy for men with low-risk localized prostate cancer, in recognition of the knowledge that the majority of men with such cancers are likely to die from other causes. The most obvious benefit of active surveillance is the reduction of morbidity associated with surgery by delaying or avoiding radical gland therapy. Other advantages include lower overall costs to the health-care system and potentially a better quality of life. These advantages should be balanced against the risks of delayed therapy, the most considerable of which being development of more-aggressive disease. Appropriate selection criteria and the definition of triggers for intervention with radical therapy are critical components of an active surveillance protocol. The ability to accurately identify and cure the men whose cancers will progress using clinical, biopsy and imaging data is yet to be resolved, as is the psychological burden of living with an untreated cancer. The benefit of 5α-reductase inhibitors as secondary chemoprevention in men on active surveillance is a new avenue of research. Focal therapy, which has the similar aim of reducing morbidity while maintaining oncological control, is an emerging competitor for active surveillance. Nevertheless, active surveillance is an appealing management option for selected men with prostate cancer.