Risk stratification and validation of prostate specific antigen density as independent predictor of progression in men with low risk prostate cancer during active surveillance

Validation of a prognostic blood-based sphingolipid panel for men with localized prostate cancer followed on active surveillance

BACKGROUND

We previously reported that increases in circulating sphingolipids are associated with elevated risk of biopsy Gleason grade group (GG) upgrading in men on Active Surveillance (AS) for prostate cancer. Here, we aimed to validate these findings and establish a blood-based sphingolipid biomarker panel for identifying men on AS who are at high-risk of biopsy GG upgrading.

METHODS

Men diagnosed with low- or intermediate-risk prostate cancer in one of two AS cohorts (CANARY PASS and MDACC) were followed for GG upgrading after diagnostic and confirmatory biopsy. The PASS cohort consisted of 544 patients whereas the MDACC Cohort consisted of 697 patients. The number of patients with GG upgrading during course of study follow-up in the PASS and MDACC cohorts were 98 (17.7%) and 133 (19.1%), respectively. Plasmas collected prior to confirmatory biopsy were used for mass spectrometry-based quantitation of 87 unique sphingolipid species. A neural network layer based on 21 sphingolipids was developed in the CANARY PASS cohort for predicting biopsy GG upgrading. Tertile-based thresholds for low-, intermediate-, and high-risk strata were subsequently developed for the sphingolipid panel as well as a model that combined the sphingolipid panel with PSA density and rate of core positivity on diagnostic biopsy. The resultant models and risk thresholds for GG upgrading were validated in the MDACC cohort. Performance was assessed using Cox proportional hazard models, C-index, AUC, and cumulative incidence curves.

RESULTS

The sphingolipid panel had a HR (per unit standard deviation increase) of 1.36 (95% CI: 1.07-1.70) and 1.35 (95% CI: 1.11-1.64) for predicting GG biopsy upgrading in the PASS and MDACC cohort, respectively. The model that combined the sphingolipid panel with PSA density and rate of core positivity achieved a HR of 1.63 (95% CI: 1.33-2.00) and 1.44 (1.25-1.66), respectively. Tertile-based thresholds, established in the PASS cohort, were applied to the independent MDACC cohort. Compared to the low-risk group, MDACC patients in the high-risk strata had a GG biopsy upgrade HR of 3.65 (95% CI: 2.21-6.02), capturing 50% of the patients that had biopsy upgrading during study follow-up.

CONCLUSIONS

The sphingolipid panel is independently associated with GG biopsy upgrading among men in two independent AS cohorts who have previously undergone diagnostic and confirmatory biopsy. The sphingolipid panel, together with clinical factors, provides a potential means for risk stratification to better guide clinical management of men on AS.

Impact of family history of prostate cancer on disease progression for prostatic cancer patients undergoing active surveillance: A systematic review and meta-analysis

PURPOSE

To evaluate how a family history of prostate cancer influences the progression of the disease in individuals with prostate cancer undergoing active surveillance.

MATERIALS AND METHODS

We conducted a thorough literature search in PubMed/MEDLINE, Embase, and Cochrane Library up to June 2023. This systematic review was registered in PROSPERO (CRD42023441853). The study evaluated the effects of family history of prostate cancer (intervention) on disease progression (outcome) in prostate cancer patients undergoing active surveillance (population) and compared them to those without a family history (comparators). For time to disease progression outcomes, the extracted data were synthesized using the inverse variance method on the log hazard ratios scale.

RESULTS

A total of eight studies were incorporated into this systematic review and meta-analysis. The combined hazard ratio for unadjusted disease progression was 1.06 (95% confidential interval [CI] 0.66-1.69; p=0.82). The combined hazard ratio for adjusted disease progression was 1.31 (95% CI 1.16-1.48; p<0.0001). All the enlisted studies demonstrated high quality based on the Newcastle-Ottawa scale. The certainty of evidence for univariate and multivariate analysis of disease progression was very low and low, respectively. Publication bias for all studies was not significant.

CONCLUSIONS

For individuals with prostate cancer opting for active surveillance, a family history of prostate cancer may serve as an independent risk factor associated with an elevated risk of disease progression. Clinicians should be counseled about the increased risk of disease progression in patients with a family history of prostate cancer undergoing active surveillance.

Contemporary Strategies for Clinical Chemoprevention of Localized Prostate Cancer

Prostate cancer (PCa) is the most common cancer among men in the United States and the second leading cause of cancer-related deaths. Metastatic castration-resistant PCa is still a fatal disease. On the other hand, between 2016 and 2020, about 70% of PCa cases were diagnosed at a localized stage. Evolving data demonstrates that men with low-grade cancers treated with definitive therapies may now be exposed to morbidities of overtreatment and poor quality of life, with little or no benefit in terms of cancer specific mortality. Active surveillance (AS) is thus the recommended management strategy for men with low-grade disease. Although this subgroup of men have reported anxiety during the AS period, they account to be highly motivated to make positive lifestyle changes to further reduce their risk of PCa progression, underscoring the urgent need to identify novel strategies for preventing progression of localized PCa to metastatic disease through pharmacologic means, an approach termed chemoprevention. Although several promising agents and approaches have been examined over the past 2 decades, currently, there are several limitations in the approach used to systematically examine agents for chemoprevention targeting men on AS. The goal of this review is to summarize the current agents and approaches evaluated, targeting men on AS, recognize the gaps, and identify a contemporary and comprehensive path forward. Results of these studies may inform the development of phase III clinical trials and ultimately provide a strategy for clinical chemoprevention in men on AS, for whom, currently, there are no options for reducing the risk of progression to metastatic disease.

Investigating High-risk Factors, Precise Diagnosis, and Treatment of Castration- Resistant Prostate Cancer (CRPC)

BACKGROUND

The treatment of metastatic castration-resistant prostate cancer (mCRPC) in the actual world currently presents difficulties. In light of this, it is crucial to investigate high-risk factors for the progression of advanced prostate cancer and to identify methods for delaying the onset of CRPC.

AIMS

This study aimed to explore the high-risk factors that impact the progression of prostate cancer and emphasize the significance of precise diagnosis and treatment based on etiological classification in the clinical management of castration-resistant prostate cancer.

METHODS

A retrospective analysis was conducted on 277 newly diagnosed cases of PCa treated with endocrine therapy. A follow-up was done on prostate-specific antigen (PSA) levels and testosterone. Additionally, a prospective analysis was performed on the clinical data of 60 patients with CRPC. Following the principle of "4W1H", 30 patients were included in the precision treatment group for a second biopsy and related tests, while another 30 patients were included in the conventional treatment group. The therapeutic effect and prognosis of the two groups were observed.

RESULTS

Distant metastasis (HR = 1.879, 95% CI: 1.311 ~ 2.694, P = 0.001), PSA nadir > 0.2 ng/mL (HR = 1.843, 95% CI: 1.338 ~ 2.540, P = 0.001), testosterone nadir > 20 ng/dL (HR = 1.403, 95% CI: 1.035 ~ 1.904, P = 0.029), and time to testosterone nadir > 6 months (HR = 1.919, 95% CI: 1.364 ~ 2.701, P = 0.001) were risk factors for the progression to CRPC. Patients in the CRPC group were treated with precision therapy and conventional therapy based on their molecular subtyping. The precision treatment group showed a significantly prolonged median PSA progression-free survival compared to the conventional treatment group (16.0 months vs. 13.0 months, P=0.025). The median radiographic progression-free survival was also significantly extended in the precision treatment group compared to the conventional treatment group (21.0 months vs. 16.0 months, P=0.042).

CONCLUSION

Patients with prostate cancer diagnosed with distant metastasis at initial presentation require early intervention. Close monitoring of PSA and serum testosterone changes is necessary during the process of endocrine therapy. After entering the CRPC stage, the etiological classification precision treatment can improve the therapeutic effect and improve the prognosis of patients.

Is Active Surveillance an Option for the Management of Men with Low-grade Prostate Cancer and a Positive Family History? Results from a Large, Single-institution Series

BACKGROUND

Family history (FH) of prostate cancer (PCa) is associated with an increased risk of PCa and adverse disease features. However, whether patients with localized PCa and FH could be considered for active surveillance (AS) remains controversial.

OBJECTIVE

To assess the association between FH and reclassification of AS candidates, and to define predictors of adverse outcomes in men with positive FH.

DESIGN, SETTING, AND PARTICIPANTS

Overall, 656 patients with grade group (GG) 1 PCa included in an AS protocol at a single institution were identified.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Kaplan-Meier analyses assessed the time to reclassification (GG ≥2 and GG ≥3 at follow-up biopsies) overall and according to FH status. Multivariable Cox regression tested the impact of FH on reclassification and identified the predictors among men with FH. Men treated with delayed radical prostatectomy (n = 197) or external-beam radiation therapy (n = 64) were identified, and the impact of FH on oncologic outcomes was assessed.

RESULTS AND LIMITATIONS

Overall, 119 men (18%) had FH. The median follow-up was 54 mo (interquartile range 29-84 mo), and 264 patients experienced reclassification. The 5-yr reclassification-free survival rate was 39% versus 57% for FH versus no FH (p = 0.006), and FH was associated with reclassification to GG ≥2 (hazard ratio [HR] 1.60, 95% confidence interval [CI] 1.19-2.15, p = 0.002). In men with FH, the strongest predictors of reclassification were prostate-specific antigen (PSA) density (PSAD), high-volume GG 1 (≥33% of cores involved or ≥50% of any core involved), and suspicious magnetic resonance imaging (MRI) of the prostate (HRs 2.87, 3.04, and 3.87, respectively; all p < 0.05). No association between FH, adverse pathologic features, and biochemical recurrence was observed (all p > 0.05).

CONCLUSIONS

Patients with FH on AS are at an increased risk of reclassification. Negative MRI, low disease volume, and low PSAD identify men with FH and a low risk of reclassification. Nonetheless, sample size and wide CIs entail caution in drawing conclusions based on these results.

PATIENT SUMMARY

We tested the impact of family history in men on active surveillance for localized prostate cancer. A significant risk of reclassification, but not adverse oncologic outcomes after deferred treatment, prompts the need for cautious discussion with these patients, without precluding initial expectant management.

Genetic predisposition to prostate cancer: an update

Improvements in DNA sequencing technology and discoveries made by large scale genome-wide association studies have led to enormous insight into the role of genetic variation in prostate cancer risk. High-risk prostate cancer risk predisposition genes exist in addition to common germline variants conferring low-moderate risk, which together account for over a third of familial prostate cancer risk. Identifying men with additional risk factors such as genetic variants or a positive family history is of clinical importance, as men with such risk factors have a higher incidence of prostate cancer with some evidence to suggest diagnosis at a younger age and poorer outcomes. The medical community remains in disagreement on the benefits of a population prostate cancer screening programme reliant on PSA testing. A reduction in mortality has been demonstrated in many studies, but at the cost of significant amounts of overdiagnosis and overtreatment. Developing targeted screening strategies for high-risk men is currently the subject of investigation in a number of prospective studies. At present, approximately 38% of the familial risk of PrCa can be explained based on published SNPs, with men in the top 1% of the risk profile having a 5.71-fold increase in risk of developing cancer compared with controls. With approximately 170 prostate cancer susceptibility loci now identified in European populations, there is scope to explore the clinical utility of genetic testing and genetic-risk scores in prostate cancer screening and risk stratification, with such data in non-European populations eagerly awaited. This review will focus on both the rare and common germline genetic variation involved in hereditary and familial prostate cancer, and discuss ongoing research in exploring the role of targeted screening in this high-risk group of men.

Utility of PSA Density in Predicting Upgraded Gleason Score in Men on Active Surveillance With Negative MRI

OBJECTIVES

To determine whether PSA density (PSAD), can sub-stratify risk of biopsy upgrade among men on active surveillance (AS) with normal baseline MRI.

METHODS

We identified a cohort of patients with low and favorable intermediate-risk prostate cancer on AS at two large academic centers from February 2013 - December 2017. Analysis was restricted to patients with GG1 cancer on initial biopsy and a negative baseline or surveillance mpMRI, defined by the absence of PI-RADS 2 or greater lesions. We assessed ability of PSA, prostate volume and PSAD to predict upgrading on confirmatory biopsy.

RESULTS

We identified 98 patients on AS with negative baseline or surveillance mpMRI. Median PSA at diagnosis was 5.8 ng/mL and median PSAD was 0.08 ng/mL/mL. Fourteen men (14.3%) experienced Gleason upgrade at confirmatory biopsy. Patients who were upgraded had higher PSA (7.9 vs 5.4 ng/mL, P = .04), PSAD (0.20 vs 0.07 ng/mL/mL, P < .001), and lower prostate volumes (42.5 vs 65.8 mL, P = .01). On multivariate analysis, PSAD was associated with pathologic upgrade (OR 2.23 per 0.1-increase, P = .007). A PSAD cutoff at 0.08 generated a NPV of 98% for detection of pathologic upgrade.

CONCLUSION

PSAD reliably discriminated the risk of Gleason upgrade at confirmatory biopsy among men with low-grade prostate cancer with negative MRI. PSAD could be clinically implemented to reduce the intensity of surveillance for a subset of patients.

Application of metastatic biopsy based on "When, Who, Why, Where, How (4W1H)" principle in diagnosis and treatment of metastatic castration-resistance prostate cancer

Background

To determine the feasibility of secondary biopsy of metastatic castration-resistance prostate cancer based on the "4W1H-When, Who, Why, Where, How" principle and analyze the factors that affect tumor detection. Its application will further direct the patients for individualized precision therapy.

Methods

A total of 55 patients were collected for secondary biopsy (27 prostate biopsies and 55 metastases biopsies). The parameters of biopsy location, computed tomography attenuation coefficient, lesion size, core number, laboratory tests, and the use of bone protection were evaluated. Histopathological data and the pathogenesis and etiology classification were used to guide precision treatment.

Results

Fifteen/27 patients had a positive prostate biopsy, and 47/55 had positive metastasis biopsy. Bone metastasis biopsy was positive in 21/29 of cases. Also, parenchymal organs and lymph node biopsies were positive. In the prostate rebiopsy, significant differences were observed between total prostate volume (P=0.028), prostate-specific antigen (PSA) density (P=0.047), PSA velocity (P=0.036), and positive biopsy results. In the bone metastasis biopsy, we divided the patients into biopsy-positive and -negative groups. The computed tomography attenuation coefficient, PSA, alkaline phosphatase, and hemoglobin were related to tumor positive detection. However, the lesion size, core number, bone-sparing agents and previous treatments did not affect tumor detection.

Conclusions

In metastatic castration-resistant prostate cancer (mCRPC) patients, the "4W1H" principle was applied in the second biopsy. The biopsy site, image, and laboratory variables affected the positive of tumor tissue. Further pathological analysis of tumor tissue is essential to guide the precision medicine of mCRPC etiological classification.

Multiparametric MRI in the management of prostate cancer: an update-a narrative review

The growing interest in multiparametric MRI is leading to important changes in the diagnostic process of prostate cancer. MRI-targeted biopsy is likely to become a standard for the diagnosis of prostate cancer in the next years. Despite it is well known that MRI has no role as a staging technique, it is clear that multiparametric MRI may be of help in active surveillance protocols. Noteworthy, MRI in active surveillance is not recommended, but a proper understanding of its potential may be of help in achieving the goals of a delayed treatment strategy. Moreover, the development of minimally invasive techniques, like laparoscopic and robotic surgery, has led to greater expectations as regard to the functional outcomes of radical prostatectomy. Multiparametric MRI may play a role in planning surgical strategies, with the aim to provide the highest oncologic outcome with a minimal impact on the quality of life. We maintain that a proper anatomic knowledge of prostate lesions may allow the surgeon to achieve a better result in planning as well as in performing surgery and help the surgeon and the patient engage in a shared decision in planning a more effective strategy for prostate cancer control and treatment. This review highlights the advantages and the limitations of multiparametric MRI in prostate cancer diagnosis, in active surveillance and in planning surgery.

Safety of testosterone therapy in men with prostate cancer

Introduction: The use of testosterone therapy (TTh) in men with prostate cancer (PCa) is relatively new, and controversial, due to the longstanding maxim that TTh is contraindicated in men with PCa. Scientific advances have prompted a reevaluation of the potential role for TTh in men with PCa, particularly as TTh has been shown to provide important symptomatic and general health benefits to men with testosterone deficiency (TD), including many men with PCa who may expect to live 30-50 years after diagnosis. Areas covered: This review outlines the historical underpinnings of the historical belief that TTh 'fuels' PCa and the experimental and clinical studies that have radically altered this view, including description of the saturation model. The authors review studies of TTh in men with PCa following radical prostatectomy and radiation therapy, in men on active surveillance, and in men with advanced or metastatic PCa. Expert opinion: TTh provides important symptomatic and overall health benefits for men with PCa who have TD. Although more safety studies are needed, TTh is a reasonable therapeutic option for men with low-risk PCa after surgery or radiation. Data in men on active surveillance are limited, but initial reports are reassuring.

Impact of bilateral biopsy-detected prostate cancer on an active surveillance population

BACKGROUND

To assess factors that can predict active surveillance (AS) failure on serial transrectal ultrasound guided biopsies in patients with low-risk prostate cancer.

METHODS

We evaluated the records of 144 consecutive patients enrolled in AS between 2007 and 2014 at a single academic institution. Low risk inclusion criteria included PSA < 10 ng/ml, cT1c or cT2a, Grade Group (GG) 1, < 3 positive cores, and < 50% tumor in a single core with the majority having a PSA density of < 0.15. AS reclassification was defined as progression to GG ≥2, 3 or more cores, or core tumor volume ≥ 50%. Univariate and multivariate Cox proportional hazards regression analysis was used to determine predictors of reclassification and a match-pair analysis performed on a control group of patients choosing surgery.

RESULTS

Inclusion criteria were met by 130 men with a median follow-up of 52 months. The reclassification or AS failure rate was 38.5%, with the majority 41/50 (82%) finding GG ≥ 2 cancer. Most patients had unilateral disease on diagnostic biopsy (94.6%), but 40.7% had bilateral cancer detected during follow-up. Men with bilateral detected tumor were more likely to ultimately fail AS than patients with unilateral tumors (HR 4.089; P < 0.0001) and failed earlier with a reclassification-free survival of 32 vs 119 months respectively. In a matched-pair analysis using a population of 211 concurrent patients that chose radical prostatectomy rather than AS, 76% of patients with unilateral cancer on biopsy had bilateral cancer on final pathology.

CONCLUSIONS

The finding of bilateral prostate cancer on biopsy is associated with earlier AS reclassification. Finding bilateral disease may not represent disease progression, but rather enhanced detection of more extensive disease highlighting the importance of confirmatory biopsy.

Green tea extract for prevention of prostate cancer progression in patients on active surveillance

Background

Active surveillance (AS) has evolved as a management strategy for men with low grade prostate cancer (PCa). However, these patients report anxiety, doubts about the possible progression of the disease as well as higher decisional conflict regarding selection of active surveillance, and have been reported to ultimately opt for treatment without any major change in tumor characteristics. Currently, there is a paucity of research that systematically examines alternate strategies for this target population.

Methods

We conducted a review the evidence from epidemiological, in vitro, preclinical and early phase trials that have evaluated green tea catechins (GTC) for secondary chemoprevention of prostate cancer, focused on men opting for active surveillanceof low grade PCa.

Results

Results of our review of the in vitro, preclinical and phase I-II trials, demonstrates that green tea catechins (GTC) can modulate several relevant intermediate biological intermediate endpoint biomarkers implicated in prostate carcinogenesis as well as clinical progression of PCa, without major side effects.

Discussion

Although clinical trials using GTC have been evaluated in early phase trials in men diagnosed with High-Grade Prostatic Intraepithelial Neoplasia, Atypical Small Acinar Proliferation and in men with localized disease before prostatectomy, the effect of GTC on biological and clinical biomarkers implicated in prostate cancer progression have not been evaluated in this patient population.

Conclusion

Results of these studies promise to provide a strategy for secondary chemoprevention, reduce morbidities due to overtreatment and improve quality of life in men diagnosed with low-grade PCa.

Clinical and pathologic factors predicting reclassification in active surveillance cohorts

The incidence of small, lower risk well-differentiated prostate cancer is increasing and almost half of the patients with this diagnosis are candidates for initial conservative management in an attempt to avoid overtreatment and morbidity associated with surgery or radiation. A proportion of patients labeled as low risk, candidates for Active Surveillance (AS), harbor aggressive disease and would benefit from definitive treatment. The focus of this review is to identify clinicopathologic features that may help identify these less optimal AS candidates. A systematic Medline/PubMed Review was performed in January 2017 according to PRISMA guidelines; 83 articles were selected for full text review according to their relevance and after applying limits described. For patients meeting AS criteria including Gleason Score 6, several factors can assist in predicting those patients that are at higher risk for reclassification including higher PSA density, bilateral cancer, African American race, small prostate volume and low testosterone. Nomograms combining these features improve risk stratification. Clinical and pathologic features provide a significant amount of information for risk stratification (>70%) for patients considering active surveillance. Higher risk patient subgroups can benefit from further evaluation or consideration of treatment. Recommendations will continue to evolve as data from longer term AS cohorts matures.

Biomarkers in active surveillance

The use of active surveillance (AS) is increasing for favorable-risk prostate cancer. However, there remain challenges in patient selection for AS, due to the limitations of current clinical staging. In addition, monitoring protocols relying on serial biopsies is invasive and presents risks such as infection. For these reasons, there is substantial interest in identifying markers that can be used to improve AS selection and monitoring. In this article, we review the evidence on serum, urine and tissue markers in AS.

The Within-Group Discrimination Ability of the Cancer of the Prostate Risk Assessment Score for Men with Intermediate-Risk Prostate Cancer

BACKGROUND

Significant clinical heterogeneity within contemporary risk group is well known, particularly for those with intermediate-risk prostate cancer (IRPCa). Our study aimed to analyze the ability of the Cancer of the Prostate Risk Assessment (CAPRA) score to discern between favorable and non-favorable risk in patients with IRPCa.

METHODS

We retrospectively reviewed the data of 203 IRPCa patients who underwent extraperitoneal robot-assisted radical prostatectomy (RARP) performed by a single surgeon. Pathologic favorable IRPCa was defined as a Gleason score ≤ 6 and organ-confined stage at surgical pathology. The CAPRA score was compared with two established criteria for the within-group discrimination ability.

RESULTS

Overall, 38 patients (18.7% of the IRPCa cohort) had favorable pathologic features after RARP. The CAPRA score significantly correlated with established criteria I and II and was inversely associated with favorable pathology (all P < 0.001). The area under the receiver operating characteristic curve for the discriminative ability between favorable and non-favorable pathology was 0.679 for the CAPRA score and 0.610 and 0.661 for established criteria I and II, respectively. During a median 37.8 (interquartile range, 24.6-60.2) months of follow-up, 66 patients (32.5%) experienced biochemical recurrence (BCR). Cox regression analysis revealed that the CAPRA score, as a continuous sum score model or 3-group risk model, was an independent predictor of BCR after RARP.

CONCLUSION

The within-group discrimination ability of preoperative CAPRA score might help in patient counseling and selecting optimal treatments for those with IRPCa.

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.

Prognostic Significance of a Negative Confirmatory Biopsy on Reclassification Among Men on Active Surveillance

OBJECTIVE

To examine the association between absence of disease on confirmatory biopsy and risk of pathologic reclassification in men on active surveillance (AS).

MATERIALS AND METHODS

Men with grade groups 1 and 2 disease on AS between 2002 and 2015 were identified who received a confirmatory biopsy within 1 year of diagnosis and ≥3 biopsies overall. The primary outcomes were pathologic reclassification by grade (any increase in primary Gleason pattern or Gleason score) or volume (>33% of sampled cores involved or increase in the number of cores with >50% involvement). The effect of a negative confirmatory biopsy survival was evaluated using Kaplan-Meier analysis and a Cox proportional hazards modeling.

RESULTS

Out of 635 men, 224 met inclusion criteria (median follow-up: 55.8 months). A total of 111 men (49.6%) had a negative confirmatory biopsy. Decreased grade reclassification (69.7% vs 83.9%; P = .01) and volume reclassification (66.3% vs 87.4%; P = .004) was seen at 5 years for men with a negative confirmatory biopsy compared with those with a positive biopsy. On adjusted analysis, a negative confirmatory biopsy was associated with a decreased risk of grade reclassification (hazard ratio, 0.51; 95% confidence interval, 0.28-0.94; P = .03) and volume reclassification (hazard ratio, 0.32; 95% confidence interval, 0.17-0.61; P = .0006) at a median of 4.7 years.

CONCLUSION

Absence of cancer on the confirmatory biopsy is associated with a significant decrease in rate of grade and volume reclassification among men on AS. This information may be used to better counsel men on AS.

Eleven-year management of prostate cancer patients on active surveillance: what have we learned?

PURPOSE

To evaluate the outcomes of active surveillance (AS) on patients with low-risk prostate cancer (PCa) and to identify predictors of disease reclassification.

METHODS

In 2005, we defined an institutional AS protocol (Sorveglianza Attiva Istituto Nazionale Tumori [SAINT]), and we joined the Prostate Cancer Research International: Active Surveillance (PRIAS) study in 2007. Eligibility criteria included clinical stage ≤T2a, initial prostate-specific antigen (PSA) <10 ng/mL, and Gleason Pattern Score (GPS) ≤3 + 3 (both protocols); ≤25% positive cores with a maximum core length containing cancer ≤50% (SAINT); and ≤2 positive cores and PSA density <0.2 ng/mL/cm3 (PRIAS). Switching to active treatment was advised for a worsening of GPS, increased positive cores, or PSA doubling time <3 years. Active treatment-free survival (ATFS) was assessed using the Kaplan-Meier method. Factors associated with ATFS were evaluated with a multivariate Cox proportional hazards model.

RESULTS

A total of 818 patients were included: 200 in SAINT, 530 in PRIAS, and 88 in personalized AS monitoring. Active treatment-free survival was 50% after a median follow-up of 60 months. A total of 404/818 patients (49.4%) discontinued AS: 274 for biopsy-related reclassification, 121/404 (30%) for off-protocol reasons, 9/404 (2.2%) because of anxiety. Biopsy reclassification was associated with PSA density (hazard ratio [HR] 1.8), maximum percentage of core involvement (HR 1.5), positive cores at diagnostic biopsy (HR 1.6), older age (HR 1.5), and prostate volume (HR 0.6) (all p<0.01). Patients from SAINT were significantly more likely to discontinue AS than were the patients from PRIAS (HR 1.65, p<0.0001).

CONCLUSIONS

Five years after diagnosis, 50% of patients with early PCa were spared from active treatment. Wide inclusion criteria are associated with lower ATFS. However, at preliminary analysis, this does not seem to affect the probability of unfavorable pathology.

Effects of Testosterone on Benign and Malignant Conditions of the Prostate

PURPOSE OF THE REVIEW

This review summarizes the current literature regarding the effects of testosterone therapy (TTh) on common disorders of the prostate.

RECENT FINDINGS

Testosterone therapy has gained credibility over the last several decades as a potentially safe co-treatment modality for men with benign and malignant prostatic conditions. Our understanding of the effects of testosterone on the prostate continues to evolve with ongoing clinical and basic science research. Findings of these studies have reinvigorated the debate over the effects of testosterone on benign and malignant disorders of the prostate, including BPH, chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), and prostate cancer.

SUMMARY

Despite the burgeoning body of data claiming the safety and efficacy of TTh in common prostatic conditions (including BPH, CP/CPPS, and prostate cancer), diligent monitoring, appropriate patient selection, and informed consent are critical until more definitive studies are performed.

Prostate-specific antigen density is predictive of outcome in suboptimal prostate seed brachytherapy

PURPOSE

In prostate seed brachytherapy, a D₉₀ of <130 Gy is an accepted predictive factor for biochemical failure (BF). We studied whether there is a subpopulation that does not need additional treatment after a suboptimal permanent seed brachytherapy implantation.

METHODS AND MATERIALS

A total of 486 patients who had either BF or a minimum followup of 48 months without BF were identified. BF was defined according to the Phoenix definition (nadir prostate-specific antigen + 2). Univariate and multivariate analyses were performed, adjusting for known prognostic factors such as D₉₀ and prostate-specific antigen density (PSAD) of ≥0.15 ng/mL/cm³, to evaluate their ability to predict BF.

RESULTS

Median followup for patients without BF was 72 months (interquartile range 56-96). BF-free recurrence rate at 5 years was 95% and at 8 years 88%. In univariate analysis, PSAD and cancer of the prostate risk assessment score were predictive of BF. On multivariate analysis, none of the factors remained significant. The best prognosis had patients with a low PSAD (<0.15 ng/mL/cm³) and an optimal implant at 30 days after implantation (as defined by D₉₀ ≥ 130 Gy) compared to patients with both factors unfavorable (p = 0.006). A favorable PSAD was associate with a good prognosis, independently of the D₉₀ (<130 Gy vs. ≥130 Gy, p = 0.7).

CONCLUSIONS

Patients with a PSAD of <0.15 ng/mL/cm³ have little risk of BF, even in the case of a suboptimal implant. These results need to be validated in other patients' cohorts.

Prostate-specific antigen density predicts favorable pathology and biochemical recurrence in patients with intermediate-risk prostate cancer

This study was designed to identify clinical predictors of favorable pathology and biochemical recurrence (BCR) in patients with intermediate-risk prostate cancer (IRPCa). Between 2006 and 2012, clinicopathological and oncological data from 203 consecutive men undergoing robot-assisted radical prostatectomy (RARP) for IRPCa were reviewed in a single-institutional retrospective study. Favorable pathology was defined as Gleason score ≤6 and organ-confined cancer as detected by surgical pathology. Logistic regression analysis was used to determine predictive variables of favorable pathology, and the Kaplan–Meier and multivariate Cox regression model were used to estimate BCR-free survival after RARP. Overall, 38 patients (18.7%) had favorable pathology after RARP. Lower quartile prostate-specific antigen density (PSAD) was associated with favorable pathology compared to the highest quartile PSAD after adjusting for preoperative PSA, clinical stage and biopsy Gleason score (odds ratio, 5.42; 95% confidence interval, 1.01–28.97; P = 0.048). During a median 37.8 (interquartile range, 24.6–60.2) months of follow-up, 66 patients experienced BCR. There were significant differences with regard to BCR free survival by PSAD quartiles (log rank, P = 0.003). Using a multivariable Cox proportion hazard model, PSAD was found to be an independent predictor of BCR in patients with IRPCa after RARP (hazard ratio, 4.641; 95% confidence interval, 1.109–19.417; P = 0.036). The incorporation of the PSAD into risk assessments might provide additional prognostic information and identify some patients in whom active surveillance would be appropriate in patients with IRPCa.

Active surveillance as a therapeutic option for patients with low-risk prostate cancer according to the 2014 International Society of Urological Pathology grading system: a review

Extended prostate-specific antigen screening and the tightly focused execution of biopsies have resulted in an increased rate of detection, and thereby increased interventional treatment, of prostate cancer (PCa). The potential overdiagnosis and overtreatment of PCa patients have repeatedly been criticized in national and international literature. Controlled monitoring of patients in the setting of active surveillance (AS) can prevent overtreatment and the needless impairment of quality of life. The prerequisite for this treatment strategy is the diagnosis of low-grade/risk PCa. Since 2005, the modified Gleason grading system has been used for the histological assessment of PCa. In 2014, the International Society of Urological Pathology recommended a new prognostic grading system with five grades analogous to the modified Gleason score. This review discusses the importance of pathological histological analysis of PCa, particularly in the face of recent amendments, and sheds light on the significance of the new grading system for the diagnosis of low-grade/risk PCa with regard to the therapeutic option of AS.

Timing of Adverse Prostate Cancer Reclassification on First Surveillance Biopsy: Results from the Canary Prostate Cancer Active Surveillance Study

PURPOSE

During active surveillance for localized prostate cancer, the timing of the first surveillance biopsy varies. We analyzed the Canary PASS (Prostate Cancer Active Surveillance Study) to determine biopsy timing influence on rates of prostate cancer adverse reclassification at the first active surveillance biopsy.

MATERIALS AND METHODS

Of 1,085 participants in PASS, 421 had fewer than 34% of cores involved with cancer and Gleason sum 6 or less, and thereafter underwent on-study active surveillance biopsy. Reclassification was defined as an increase in Gleason sum and/or 34% or more of cores with prostate cancer. First active surveillance biopsy reclassification rates were categorized as less than 8, 8 to 13 and greater than 13 months after diagnosis. Multivariable logistic regression determined association between reclassification and first biopsy timing.

RESULTS

Of 421 men, 89 (21.1%) experienced reclassification at the first active surveillance biopsy. Median time from prostate cancer diagnosis to first active surveillance biopsy was 11 months (IQR 7.8-13.8). Reclassification rates at less than 8, 8 to 13 and greater than 13 months were 24%, 19% and 22% (p = 0.65). On multivariable analysis, compared to men biopsied at less than 8 months the OR of reclassification at 8 to 13 and greater than 13 months were 0.88 (95% CI 0.5,1.6) and 0.95 (95% CI 0.5,1.9), respectively. Prostate specific antigen density 0.15 or greater (referent less than 0.15, OR 1.9, 95% CI 1.1, 4.1) and body mass index 35 kg/m² or greater (referent less than 25 kg/m², OR 2.4, 95% CI 1.1,5.7) were associated with increased odds of reclassification.

CONCLUSIONS

Timing of the first active surveillance biopsy was not associated with increased adverse reclassification but prostate specific antigen density and body mass index were. In low risk patients on active surveillance, it may be reasonable to perform the first active surveillance biopsy at a later time, reducing the overall cost and morbidity of active surveillance.

Can testosterone therapy be offered to men on active surveillance for prostate cancer? Preliminary results

This report presents our experience with T therapy in a cohort of T-deficient men on active surveillance (AS) for Gleason 3 + 3 and Gleason 3 + 4 prostate cancer (PCa). A retrospective chart review identified 28 men with T deficiency who underwent T therapy (T group) for at least 6 months while on AS for PCa. A comparison group of 96 men on AS for PCa with untreated T deficiency (no-T group) was identified at the same institution. The AS protocol followed a modified Epstein criteria and allowed inclusion of men with a single core of low-volume Gleason 3 + 4 PCa. Mean age was 59.5 and 61.3 years, and mean follow-up was 38.9 and 42.4 months for the T and no-T groups, respectively. Of all 28 men in the T group, 3 (10.7%) men developed an increase in Gleason score while on AS. Of 22 men in the T group with Gleason 3 + 3 disease, 7 (31.8%) men developed biopsy progression including 3 men (13.6%) who developed Gleason 3 + 4 PCa. Of 6 men with Gleason 3 + 4 disease at baseline, 2 (33.3%) men developed an increase in tumor volume, and none developed upgrading beyond Gleason 3 + 4. All 96 men in the no-T group had Gleason 3 + 3 disease at baseline and, 43 (44.7%) developed biopsy progression, including 9 men (9.38%) with upgrading to Gleason 7 (3 + 4). Biopsy progression rates were similar for both groups and historical controls. Biopsy progression in men on AS appears unaffected by T therapy over 3 years. Prospective placebo-controlled trials of T therapy in T-deficient men on AS should be considered given the symptomatic benefits experienced by treated men.

Active surveillance for prostate cancer: current evidence and contemporary state of practice

Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

Development and internal validation of a multivariable prediction model for biochemical failure after whole-gland salvage iodine-125 prostate brachytherapy for recurrent prostate cancer

BACKGROUND

Localized recurrent prostate cancer after primary radiotherapy can be curatively treated using salvage iodine-125 ((125)I) brachytherapy. Selection is hampered by a lack of predictive factors for cancer control. This study aims to develop and internally validate a prognostic model for biochemical failure (BF) after salvage (125)I brachytherapy.

METHODS AND MATERIALS

Whole-gland salvage (125)I brachytherapy patients were treated between 1993 and 2010 in two radiotherapy centers in the Netherlands. Multivariable Cox regression was performed to assess the predictive value of clinical parameters related to BF (Phoenix-definition [prostate-specific antigen [PSA]-nadir + 2.0 ng/mL]). Missing data were handled by multiple imputation. The model's discriminatory ability was assessed with Harrell's C-statistic. Internal validation was performed using bootstrap resampling (2000 data sets). Goodness-of-fit was evaluated with calibration plots. All analyses were performed using the recently published TRIPOD (Transparent reporting of a multivariable prediction model for individual prognosis or diagnosis) statement.

RESULTS

After median followup of 74 months (range 5-138), 43 of a total 62 patients developed BF. In multivariable analysis, disease-free survival interval (DFSI) after primary therapy and pre-salvage prostate-specific antigen doubling time (PSADT) were predictors of BF: corrected hazard ratio (HR) 0.99 (95% confidence interval 0.97-0.999; p = 0.04) and 0.94 (95% confidence interval 0.89-0.99; p = 0.03), both for a 1-month increase (optimism-adjusted C-statistic 0.70). Calibration was accurate up to 36 months. Of patients with PSADT >30 months and DFSI >60 months, 36-month biochemical disease-free survival was >75%. Every 12-month increase in DFSI will allow 3-month decrease in PSADT while maintaining the same biochemical recurrence-free rates.

CONCLUSIONS

We have presented results from a cohort of patients undergoing salvage (125)I-brachytherapy. Our data show that better selection of patients is possible with the DFSI and PSADT.

Gleason Misclassification Rate Is Independent of Number of Biopsy Cores in Systematic Biopsy

OBJECTIVE

To compare the utility of saturation core biopsy and 12-core biopsy in detecting true Gleason grades, using final pathology in prostatectomy specimens as outcome measures, with a particular interest in Gleason upgrading.

PATIENTS AND METHODS

We compared the concordance rates of Gleason grades diagnosed on biopsies and prostatectomy specimens in 375 consecutive patients, including 106 saturation biopsies (18-33 cores, median = 20 cores) and 269 12-core biopsies. Grading bias was addressed by a central rereview of all cases that had discordance in reporting high Gleason grades (Gleason grade ≥ 4) on biopsies and prostatectomy specimens.

RESULTS

For patients with high Gleason grades on final pathology, saturation and 12-core biopsy schemes had a comparable sensitivity, specificity, negative and positive predictive values (72.5% vs 69.5%, 91.9% vs 97.6%, 64.2% vs 58.4%, and 94.3% vs 98.5%, respectively) in detecting high Gleason grades. On multivariate analysis, prebiopsy serum prostate-specific antigen and clinical T stage independently predicted Gleason upgrading; saturation biopsy was not a significant predictor. Approximately one-third of cases where high Gleason grade was not present in the biopsy were attributed to the confinement of high-grade tumors to unusual anatomic locations such as anterior lobes, apex, bladder neck, and parasagittal zones.

CONCLUSION

Our study showed that Gleason misclassification rate is independent of the number of biopsy cores in systematic biopsy. One of the reasons for missing high Gleason grade tumors on systematic biopsy was unusual tumor location outside of the biopsy grid, supporting the need for improved detection technique such as magnetic resonance imaging-guided targeted biopsies.

Biomarkers for prostate cancer: present challenges and future opportunities

Prostate cancer (PCa) has variable biological potential with multiple treatment options. A more personalized approach, therefore, is needed to better define men at higher risk of developing PCa, discriminate indolent from aggressive disease and improve risk stratification after treatment by predicting the likelihood of progression. This may improve clinical decision-making regarding management, improve selection for active surveillance protocols and minimize morbidity from treatment. Discovery of new biomarkers associated with prostate carcinogenesis present an opportunity to provide patients with novel genetic signatures to better understand their risk of developing PCa and help forecast their clinical course. In this review, we examine the current literature evaluating biomarkers in PCa. We also address current limitations and present several ideas for future studies.

Can Confirmatory Biopsy be Omitted in Patients with Prostate Cancer Favorable Diagnostic Features on Active Surveillance?

PURPOSE

We evaluated whether initial diagnostic parameters could predict the confirmatory biopsy result in patients initiating active surveillance for prostate cancer, to determine whether some men at low risk for disease reclassification could be spared unnecessary biopsy.

MATERIALS AND METHODS

The cohort included 392 men with Gleason 6 prostate cancer on initial biopsy undergoing confirmatory biopsy. We used univariate and multivariable logistic regression to assess if high grade cancer (Gleason 7 or greater) on confirmatory biopsy could be predicted from initial diagnostic parameters (prostate specific antigen density, magnetic resonance imaging result, percent positive cores, percent cancer in positive cores and total tumor length).

RESULTS

Median patient age was 62 years (IQR 56-66) and 47% of patients had a dominant or focal lesion on magnetic resonance imaging. Of the 392 patients 44 (11%) had high grade cancer on confirmatory biopsy, of whom 39 had Gleason 3+4, 1 had 4+3, 3 had Gleason 8 and 1 had Gleason 9 disease. All predictors were significantly associated with high grade cancer at confirmatory biopsy on univariate analysis. However, in the multivariable model only prostate specific antigen density and total tumor length were significantly associated (AUC 0.85). Using this model to select patients for confirmatory biopsy would generally provide a higher net benefit than performing confirmatory biopsy in all patients, across a wide range of threshold probabilities.

CONCLUSIONS

If externally validated, a model based on initial diagnostic criteria could be used to avoid confirmatory biopsy in many patients initiating active surveillance.

Development, validation and evaluation of an instrument for active monitoring of men with clinically localised prostate cancer: systematic review, cohort studies and qualitative study

Background

Active surveillance [(AS), sometimes called active monitoring (AM)],is a National Institute for Health and Care Excellence-recommended management option for men with clinically localised prostate cancer (PCa). It aims to target radical treatment only to those who would benefit most. Little consensus exists nationally or internationally about safe and effective protocols for AM/AS or triggers that indicate if or when men should move to radical treatment.

Objective

The aims of this project were to review how prostate-specific antigen (PSA) has been used in AM/AS programmes; to develop and test the validity of a new model for predicting future PSA levels; to develop an instrument, based on PSA, that would be acceptable and effective for men and clinicians to use in clinical practice; and to design a robust study to evaluate the cost-effectiveness of the instrument.

Methods

A systematic review was conducted to investigate how PSA is currently used to monitor men in worldwide AM/AS studies. A model for PSA change with age was developed using Prostate testing for cancer and Treatment (ProtecT) data and validated using data from two PSA-era cohorts and two pre-PSA-era cohorts. The model was used to derive 95% PSA reference ranges (PSARRs) across ages. These reference ranges were used to predict the onset of metastases or death from PCa in one of the pre-PSA-era cohorts. PSARRs were incorporated into an active monitoring system (AMS) and demonstrated to 18 clinicians and 20 men with PCa from four NHS trusts. Qualitative interviews investigated patients’ and clinicians’ views about current AM/AS protocols and the acceptability of the AMS within current practice.

Results

The systematic review found that the most commonly used triggers for clinical review of PCa were PSA doubling time (PSADT) < 3 years or PSA velocity (PSAv) > 1 ng/ml/year. The model for PSA change (developed using ProtecT study data) predicted PSA values in AM/AS cohorts within 2 ng/ml of observed PSA in up to 79% of men. Comparing the three PSA markers, there was no clear optimal approach to alerting men to worsening cancer. The PSARR and PSADT markers improved the modelc-statistic for predicting death from PCa by 0.11 (21%) and 0.13 (25%), respectively, compared with using diagnostic information alone [PSA, age, tumour stage (T-stage)]. Interviews revealed variation in clinical practice regarding eligibility and follow-up protocols. Patients and clinicians perceive current AM/AS practice to be framed by uncertainty, ranging from uncertainty about selection of eligible AM/AS candidates to uncertainty about optimum follow-up protocols and thresholds for clinical review/radical treatment. Patients and clinicians generally responded positively to the AMS. The impact of the AMS on clinicians’ decision-making was limited by a lack of data linking AMS values to long-term outcomes and by current clinical practice, which viewed PSA measures as one of several tools guiding clinical decisions in AM/AS. Patients reported that they would look to clinicians, rather than to a tool, to direct decision-making.

Limitations

The quantitative findings were severely hampered by a lack of clinical outcomes or events (such as metastases). The qualitative findings were limited through reliance on participants’ reports of practices and recollections of events rather than observations of actual interactions.

Conclusions

Patients and clinicians found that the instrument provided additional, potentially helpful, information but were uncertain about the current usefulness of the risk model we developed for routine management. Comparison of the model with other monitoring strategies will require clinical outcomes from ongoing AM/AS studies.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Age is Associated with Upgrading at Confirmatory Biopsy among Men with Prostate Cancer Treated with Active Surveillance

PURPOSE

Active surveillance is increasingly recommended for older men with low risk prostate cancer. Although older men have higher all cause mortality, they also have higher prostate cancer specific mortality. We hypothesized that older age is associated with an increased risk of Gleason score upgrading at confirmatory biopsy when controlling for prostate volume.

MATERIALS AND METHODS

We retrospectively reviewed data on 1,130 patients with prostate cancer who were treated with active surveillance from 1991 through 2011. We included 646 patients with clinical Gleason 6 or less, stage T2a or less prostate cancer, a confirmatory biopsy within 2 years of diagnostic biopsy and prostate magnetic resonance imaging before confirmatory biopsy. The primary outcome was Gleason score upgrading to 7 or greater on confirmatory biopsy. We used logistic regression to estimate the effect of age on upgrading, adjusting for magnetic resonance imaging prostate volume and other potential confounders.

RESULTS

Median age was 66 years (IQR 61-72) and median magnetic resonance imaging prostate volume was 41 ml (IQR 29-55). At confirmatory biopsy disease was upgraded in 55 of 646 patients (9%) and unchanged in 290 (45%) and biopsy was negative in 297 (46%). Older age was associated with higher odds of upgrading (adjusted OR 1.05, 95% CI 1.01-1.09, p=0.009). Larger prostate volume was associated with lower odds of upgrading (adjusted OR 0.80/10 ml increase, 95% CI 0.7-0.9, p=0.012).

CONCLUSIONS

Our findings suggest that older age is associated with an increased risk of misclassification on diagnostic biopsy. Older men who are interested in active surveillance should be counseled about the risks and benefits of confirmatory biopsy.

Systematic Review and Meta-analysis of Factors Determining Change to Radical Treatment in Active Surveillance for Localized Prostate Cancer

CONTEXT

Many men with clinically localized prostate cancer are being monitored as part of active surveillance (AS) programs, but little is known about reasons for receiving radical treatment.

OBJECTIVES

A systematic review of the evidence about AS was undertaken, with a meta-analysis to identify predictors of radical treatment.

EVIDENCE ACQUISITION

A comprehensive search of the Embase, MEDLINE and Web of Knowledge databases to March 2014 was performed. Studies reporting on men with localized prostate cancer followed by AS or monitoring were included. AS was defined where objective eligibility criteria, management strategies, and triggers for clinical review or radical treatment were reported.

EVIDENCE SYNTHESIS

The 26 AS cohorts included 7627 men, with a median follow-up of 3.5 yr (range of medians 1.5-7.5 yr). The cohorts had a wide range of inclusion criteria, monitoring protocols, and triggers for radical treatment. There were eight prostate cancer deaths and five cases of metastases in 24,981 person-years of follow-up. Each year, 8.8% of men (95% confidence interval 6.7-11.0%) received radical treatment, most commonly because of biopsy findings, prostate-specific antigen triggers, or patient choice driven by anxiety. Studies in which most men changed treatment were those including only low-risk Gleason score 6 disease and scheduled rebiopsies.

CONCLUSIONS

The wide variety of AS protocols and lack of robust evidence make firm conclusions difficult. Currently, patients and clinicians have to make judgments about the balance of risks and benefits in AS protocols. The publication of robust evidence from randomized trials and longer-term follow-up of cohorts is urgently required.

PATIENT SUMMARY

We reviewed 26 studies of men on active surveillance for prostate cancer. There was evidence that studies including men with the lowest risk disease and scheduled rebiopsy had higher rates of radical treatment.

Predictive role of free prostate-specific antigen in a prospective active surveillance program (PRIAS)

PURPOSE

To evaluate the utility of percentage of free serum PSA (%fPSA) as a predictor of adverse rebiopsy findings, treatment change and radical prostatectomy (RP) findings in a prospective active surveillance (AS) trial.

METHODS

Patients enrolled in the global PRIAS study with baseline %fPSA available were included. Putative baseline predictors (e.g. PSA, %fPSA) of adverse rebiopsy findings were explored using logistic regression analysis. Association of variables with treatment change and RP findings over time were evaluated with Cox regression analysis. Active treatment-free survival was assessed with a Kaplan-Meier method.

RESULTS

Of 3701 patients recruited to PRIAS, 939 had %fPSA measured at study entry. Four hundred and thirty-eight of them had %fPSA available after 1 year. Median follow-up was 17.2 months. First rebiopsy results were available for 595 patients and of those, 144 (24.2 %) had adverse findings. A total of 283 (30.1 %) patients discontinued surveillance, of those 181 (64.0 %) due to protocol-based reasons. Although median %fPSA values were significantly lower in patients who changed treatment, according to the multivariate regression analysis, initial %fPSA value was not predictive for treatment change or adverse rebiopsy findings. However, the probability of discontinuing AS was significantly lower in patients with "favourable" initial %fPSA characteristics and %fPSA during follow-up (initial %fPSA ≥15 and positive %fPSA velocity) compared to those with "adverse" %fPSA characteristics (initial %fPSA <15 and negative %fPSA velocity).

CONCLUSIONS

Diagnostic %fPSA provides no additional prognostic value when compared to other predictors already in use in AS protocols. However, %fPSA velocity during surveillance may aid in predicting the probability for future treatment change.

Circulating biomarkers for discriminating indolent from aggressive disease in prostate cancer active surveillance

PURPOSE OF REVIEW

To review research on the use of circulating biomarkers to predict unfavorable tumor pathology in the setting of active surveillance, or in clinical contexts that are informative for active surveillance, such as men with low-risk prostate cancer evaluated for upgrading or upstaging at surgery.

RECENT FINDINGS

Biomarkers have been evaluated in serum, plasma, urine, and expressed prostatic secretions. Only a small number of biomarkers have been evaluated in multiple studies: %free prostate-specific antigen (PSA), PSA velocity, PSA doubling time, proPSA, PCA3, TMPRSS2-ERG. Single studies with relevance to active surveillance have evaluated microRNAs, circulating tumor cells, and exosomes. The most consistent significant associations with unfavorable tumor pathology have been with %free PSA. Associations with [-2]proPSA and Prostate Health Index have also been consistent; however, three of four studies come from the same active surveillance patient cohort.

SUMMARY

Circulating biomarkers represent a promising approach to identify men with apparently low-risk biopsy pathology, but who harbor potentially aggressive tumors unsuitable for active surveillance. Research is still at an early stage; existing biomarkers need rigorous validation with consistent methodology, and additional biomarkers need to be evaluated. Successful clinical translation would reduce the frequency of surveillance biopsies, and may enhance acceptance of active surveillance.

Active surveillance for prostate cancer: a systematic review of clinicopathologic variables and biomarkers for risk stratification

CONTEXT

Active surveillance (AS) is an important strategy to reduce prostate cancer overtreatment. However, the optimal criteria for eligibility and predictors of progression while on AS are debated.

OBJECTIVE

To review primary data on markers, genetic factors, and risk stratification for patient selection and predictors of progression during AS.

EVIDENCE ACQUISITION

Electronic searches were conducted in PubMed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) from inception to April 2014 for original articles on biomarkers and risk stratification for AS.

EVIDENCE SYNTHESIS

Patient factors associated with AS outcomes in some studies include age, race, and family history. Multiple studies provide consistent evidence that a lower percentage of free prostate-specific antigen (PSA), a higher Prostate Health Index (PHI), a higher PSA density (PSAD), and greater biopsy core involvement at baseline predict a greater risk of progression. During follow-up, serial measurements of PHI and PSAD, as well as repeat biopsy results, predict later biopsy progression. While some studies have suggested a univariate relationship between urinary prostate cancer antigen 3 (PCA3) and transmembrane protease, serine 2-v-ets avian erythroblastosis virus E26 oncogene homolog gene fusion (TMPRSS2:ERG) with adverse biopsy features, these markers have not been consistently shown to independently predict AS outcomes. No conclusive data support the use of genetic tests in AS. Limitations of these studies include heterogeneous definitions of progression and limited follow-up.

CONCLUSIONS

There is a growing body of literature on patient characteristics, biopsy features, and biomarkers with potential utility in AS. More data are needed on practical applications such as combining these tests into multivariable clinical algorithms and long-term outcomes to further improve AS in the future.

PATIENT SUMMARY

Several PSA-based tests (free PSA, PHI, PSAD) and the extent of cancer on biopsy can help to stratify the risk of progression during active surveillance. Investigation of several other markers is under way.

Low free testosterone levels predict disease reclassification in men with prostate cancer undergoing active surveillance

OBJECTIVE

To determine whether total testosterone and free testosterone levels predict disease reclassification in a cohort of men with prostate cancer (PCa) on active surveillance (AS).

PATIENTS AND METHODS

Total testosterone and free testosterone concentrations were determined at the time the men began the AS protocol. Statistical analysis was performed using Student's t-test and a chi-squared test to compare groups. Odds ratios (ORs) with 95% confidence intervals (CIs) were obtained using univariate logistic regression. Receiver-operator characteristic curves were generated to determine the investigated testosterone thresholds. Kaplan-Meier curves were used to estimate time to disease reclassification. A Cox proportional hazard regression model was used for multivariate analysis.

RESULTS

A total of 154 men were included in the AS cohort, of whom 54 (35%) progressed to active treatment. Men who had disease reclassification had significantly lower free testosterone levels than those who were not reclassified (0.75 vs 1.02 ng/dL, P = 0.03). Men with free testosterone levels <0.45 ng/dL had a higher rate of disease reclassification than patients with free testosterone levels ≥0.45 (P = 0.032). Free testosterone levels <0.45 ng/dL were associated with a several-fold increase in the risk of disease reclassification (OR 4.3, 95% CI 1.25-14.73). Multivariate analysis showed that free testosterone and family history of PCa were independent predictors of disease reclassification.

CONCLUSIONS

Free testosterone levels were lower in men with PCa who had reclassification during AS. Men with moderately severe reductions in free testosterone level are at increased risk of disease reclassification.

Targeted prostate biopsy in select men for active surveillance: do the Epstein criteria still apply?

PURPOSE

Established in 1994, the Epstein histological criteria (Gleason score 6 or less, 2 or fewer cores positive and 50% or less of any core) have been widely used to select men for active surveillance. However, with the advent of targeted biopsy, which may be more accurate than conventional biopsy, we reevaluated the likelihood of reclassification upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion.

MATERIALS AND METHODS

We identified 113 men enrolled in active surveillance at our institution who met Epstein criteria and subsequently underwent confirmatory targeted biopsy via multiparametric magnetic resonance imaging-ultrasound fusion. Median patient age was 64 years, median prostate specific antigen was 4.2 ng/ml and median prostate volume was 46.8 cc. Targets or regions of interest on multiparametric magnetic resonance imaging-ultrasound fusion were graded by suspicion level and biopsied at 3 mm intervals along the longest axis (median 10.5 mm). Also, 12 systematic cores were obtained during confirmatory rebiopsy. Our reporting is consistent with START (Standards of Reporting for MRI-targeted Biopsy Studies) criteria.

RESULTS

Confirmatory fusion biopsy resulted in reclassification in 41 men (36%), including 26 (23%) due to Gleason grade 6 or greater and 15 (13%) due to high volume Gleason 6 disease. When stratified by suspicion on multiparametric magnetic resonance imaging-ultrasound fusion, the likelihood of reclassification was 24% to 29% for target grade 0 to 3, 45% for grade 4 and 100% for grade 5 (p=0.001). Men with grade 4 and 5 vs lower grade targets were greater than 3 times more likely to be reclassified (OR 3.2, 95% CI 1.4-7.1, p=0.006).

CONCLUSIONS

Upon confirmatory rebiopsy using multiparametric magnetic resonance imaging-ultrasound fusion men with high suspicion targets on imaging were reclassified 45% to 100% of the time. Criteria for active surveillance should be reevaluated when multiparametric magnetic resonance imaging-ultrasound fusion guided prostate biopsy is used.

Role of multiparametric 3.0-Tesla magnetic resonance imaging in patients with prostate cancer eligible for active surveillance

OBJECTIVE

To evaluate predictors of more aggressive disease and the role of multiparametric 3.0-T magnetic resonance imaging (MRI) in selecting patients with prostate cancer for active surveillance (AS).

PATIENTS AND METHODS

We retrospectively assessed 298 patients with prostate cancer who met the Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, defined as T1c/T2, PSA level of ≤10 ng/mL, PSA density (PSAD) of <0.2 ng/mL(2) , Gleason score <7, and one or two positive biopsy cores. All patients underwent preoperative MRI, including T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging, as well as radical prostatectomy (RP) between June 2005 and December 2011. Imaging results were correlated with pathological findings to evaluate the ability of MRI to select patients for AS.

RESULTS

In 35 (11.7%) patients, no discrete cancer was visible on MRI, while in the remaining 263 (88.3%) patients, a discrete cancer was visible. Pathological examination of RP specimens resulted in upstaging (>T2) in 21 (7%) patients, upgrading (Gleason score >6) in 136 (45.6%), and a diagnosis of unfavourable disease in 142 (47.7%) patients. The 263 patients (88.3%) with visible cancer on imaging were more likely to have their cancer status upgraded (49.8% vs 14.3%) and be diagnosed with unfavourable disease (52.1% vs 14.3%) than the 35 patients (11.7%) with no cancer visible upon imaging, and these differences were statistically significant (P < 0.001 for all). A visible cancer lesion on MRI, PSAD, and patient age were found to be predictors of unfavourable disease in multivariate analysis.

CONCLUSION

MRI can predict adverse pathological features and be used to assess the eligibility of patients with prostate cancer for AS.

Prostate specific antigen velocity risk count predicts biopsy reclassification for men with very low risk prostate cancer

PURPOSE

Prostate specific antigen velocity is an unreliable predictor of adverse pathology findings in patients on active surveillance for low risk prostate cancer. However, to our knowledge a new concept called prostate specific antigen velocity risk count, recently validated in a screening cohort, has not been investigated in an active surveillance cohort.

MATERIALS AND METHODS

We evaluated a cohort of men from 1995 to 2012 with prostate cancer on active surveillance. They had stage T1c disease, prostate specific antigen density less than 0.15 ng/ml, Gleason score 6 or less, 2 or fewer biopsy cores and 50% or less involvement of any core with cancer. The men were observed by semiannual prostate specific antigen measurements, digital rectal examinations and an annual surveillance biopsy. Treatment was recommended for biopsy reclassification. Patients with 30 months or greater of followup and 3 serial prostate specific antigen velocity measurements were used in primary analysis by logistic regression, Cox proportional hazards, Kaplan-Meier analysis and performance parameters, including the AUC of the ROC curve.

RESULTS

Primary analysis included 275 of 668 men who met very low risk inclusion criteria, of whom 83 (30.2%) were reclassified at a median of 57.1 months. Reclassification risk increased with risk count, that is a risk count of 3 (HR 4.63, 95% CI 1.54-13.87) and 2 (HR 3.73, 95% CI 1.75-7.97) compared to zero. Results were similar for Gleason score reclassification (HR 7.45, 95% CI 1.60-34.71 and 3.96, 95% CI 1.35-11.62, respectively). On secondary analysis the negative predictive value (risk count 1 or less) was 91.5% for reclassification in the next year. Adding the prostate specific antigen velocity risk count improved the AUC in a model including baseline prostate specific antigen density (0.7423 vs 0.6818, p = 0.025) and it outperformed the addition of overall prostate specific antigen velocity (0.7423 vs 0.6960, p = 0.037).

CONCLUSIONS

Prostate specific antigen velocity risk count may be useful for monitoring patients on active surveillance and decreasing the frequency of biopsies needed in the long term.

Clinical implications of family history of prostate cancer and genetic risk single nucleotide polymorphism (SNP) profiles in an active surveillance cohort

OBJECTIVES

To explore the potential prognostic role of family history (FH) of prostate cancer and prostate cancer risk single nucleotide polymorphisms (SNPs) in patients undergoing active surveillance (AS) for prostate cancer. This is the first study to date, which has investigated the potential prognostic role of SNP profiles in an AS cohort

PATIENTS AND METHODS

FH data were collected from patients in the Royal Marsden Hospital AS study. In all, 39 prostate cancer-risk SNPs identified from published genome wide association studies (GWAS) were genotyped using the Sequenom Platform and TaqMan™ assays from available DNA. The cumulative genetic-risk scores for each patient were then calculated using the weighted effect estimated from previous GWAS (log-additive model). FH status and the genetic-risk scores were assessed against adverse outcomes in AS, time to treatment and adverse histology on repeat biopsy, using univariable and multivariable Cox regression models to address time to treatment; and binary logistic regression to address biopsy upgrade.

RESULTS

Of 471 patients, 55 (13.6%) had adverse histology on repeat biopsies and 145 (30.8%) had deferred treatment. On univariate analysis, there was no significant relationship between FH of prostate cancer in any degree of relation, and adverse histology or time to treatment. For risk score analyses, 386 patients' DNA was studied; and there was also no relationship found between the calculated genetic risk scores and adverse histology or time to treatment (P = 0.573 and P = 0.965, respectively). The retrospective study design and the few events were the main limitation of the study.

CONCLUSIONS

There is currently insufficient data to support the use of FH status or prostate cancer SNP profile risk scores as prognostic factors in AS and these should not be used to influence management decisions. As more genetic variants are discovered this may change and should be reassessed in multicentre AS cohorts.

Improving risk stratification in patients with prostate cancer managed by active surveillance: a nomogram predicting the risk of biopsy progression

OBJECTIVE

To develop a clinical tool that integrates different risk factors and provides individual predictions of the risk of biopsy progression in patients with prostate cancer managed by active surveillance.

MATERIALS AND METHODS

Our analysis included 205 patients on active surveillance, each of whom had had at least two surveillance biopsies. We used the Cox proportional hazard regression model to analyse the association between different risk factors and progression-free survival over successive biopsies. This multivariate model was then used to develop a nomogram. Discrimination and calibration of the nomogram were internally validated using 200 bootstrap resamplings.

RESULTS

The median follow-up of patients free of progression was 4.6 years. A total of 58 (28%) patients experienced progression. Factors significantly associated with progression were: overall number of positive cores in the diagnostic and first surveillance biopsies, race and prostate-specific antigen density. The bootstrapping concordance index of the nomogram including these variables was 81%. The nomogram tended to underestimate the probability of progression but it identified fairly accurately the distinct groups of patients at low, intermediate and high risk of progression.

CONCLUSIONS

In the development cohort, the nomogram was able to separate patients with respect to their risk of biopsy progression. Since accurate risk stratification is essential to optimize patient care, this tool, if external validation confirms its performance, may prove useful for both the counselling and management of patients with low-volume, Gleason 6 prostate cancer.