Disease reclassification risk with stringent criteria and frequent monitoring in men with favourable-risk prostate cancer undergoing active surveillance

Five-Year Prospective Observational Study of African-American Men on Active Surveillance for Prostate Cancer Demonstrates Race Is Not Predictive of Oncologic Outcomes

INTRODUCTION

This study aimed to evaluate if race impacted outcomes or risk of disease progression in men on active surveillance (AS) for prostate cancer. We present the results from our majority African-American cohort of men in an equal access setting over a 5-year follow-up period.

PATIENTS AND METHODS

All patients who elected AS for prostate cancer at the Southeast Louisiana Veterans Health Care System are entered into a prospectively managed observational database. Patients were divided into groups based on self-reported race. Grade group progression was defined as pathologic upgrading above International Society of Urological Pathology Grade Group 1 disease on subsequent biopsies following diagnostic biopsy. All tests were 2 sided using a significance of .05.

RESULTS

A total of 228 men met inclusion criteria in the study, including 154 non-Hispanic African American and 74 non-Hispanic Caucasian American men, with a median follow-up of 5 years from the initiation of AS. Race was not predictive of Gleason grade progression, AS discontinuation, or biochemical recurrence on Cox multivariate analysis (HR = 1.01, 0.94, 0.85, P = .96, .79, .81, respectively). On Kaplan-Meier analysis at 5 years, African-American progression-free, AS discontinuation free, and overall survival probability was comparable to their Caucasian American counterparts (P > .05 for all).

CONCLUSIONS

Active surveillance is a safe treatment option for low and very low risk prostate cancer, regardless of race. African-American and Caucasian-American men did not have any significant difference in Gleason grade group progression in our cohort with 5-year follow-up.

Progression on active surveillance for prostate cancer in Black men: a systematic review and meta-analysis

BACKGROUND

Several studies evaluated prostate cancer (PCa) outcomes in Black men on active surveillance (AS); most studies contained few Black men and results were conflicting. We performed a systematic review and meta-analyze of race and outcomes on AS.

METHODS

A systematic search was performed for articles of men with Grade Group 1 or 2 (GG1 or GG2) PCa on AS. All studies required race-specific comparative progression data. Progression to treatment, PSA, or biopsy progression were considered and relative risk (RR) estimates of Black men progressing were extracted and pooled using random-effects models. Differences by study-level characteristics were evaluated using subgroup and a cumulative meta-analysis by time.

RESULTS

In total, 12 studies were included (3137 Black and 12,206 non-Black men); eight prospective (27%, n = 4210) and four retrospectives (73%, n = 11,133) cohorts. The overall RR of progression for Black men was 1.62 (95%CI, 1.21-2.17), I² = 64% (95% CI, 32-80%), (χ² = 30.23; P = 0.001; τ² = 0.16). Black men with GG1 PCa alone had a higher pooled progression: RR = 1.81 (95% CI, 1.23-2.68). Including only studies with clinical progression (excluding progression to treatment), potentiated results: RR = 1.82 (95%CI, 1.27-2.60). However, a cumulative meta-analysis demonstrated decreasing pooled effect over time, with contemporary studies after 2019 showing a tempered effect (RR: 1.29, 95% CI: 1.20-1.39).

CONCLUSIONS

Many studies attribute racial disparity in PCa to delayed presentation of disease, however, AS is unique since all AS eligible men have a low grade and stage PCa. Our findings suggest Black men may have an increased risk of progression during AS, but the association is not so strong that Black men should be discouraged from undergoing AS. Indeed, contemporary evidence suggests stricter inclusion, better confirmatory testing or better access to care may temper these findings. Importantly, these results utilize self-reported race, a social construct that has many limitations.

Genetic variants in epithelial-mesenchymal transition genes as predictors of clinical outcomes in localized prostate cancer

BACKGROUND

Epithelial-mesenchymal transition (EMT) plays a pivotal role in the progression of prostate cancer (PCa). However, little is known about genetic variants in the EMT pathway as predictors of aggressiveness, biochemical recurrence (BCR) and disease reclassification in localized PCa.

PATIENTS AND METHODS

In this multistage study, we evaluated 5186 single nucleotide polymorphisms (SNPs) from 264 genes related to EMT pathway to identify SNPs associated with PCa aggressiveness and BCR in the MD Anderson PCa (MDA-PCa) patient cohort (N = 1762), followed by assessment of the identified SNPs with disease reclassification in the active surveillance (AS) cohort (N = 392).

RESULTS

In the MDA-PCa cohort, 312 SNPs were associated with high D'Amico risk (P < 0.05), among which, 14 SNPs in 10 genes were linked to BCR risk. In the AS cohort, 2 of 14 identified SNPs (rs76779889 and rs7083961) in C-terminal Binding Proteins 2 gene were associated with reclassification risk. The associations of rs76779889 with different endpoints were: D'Amico high versus low, odds ratio [95% confidence interval (CI)] = 2.89 (1.32-6.34), P = 0.008; BCR, hazard ratio (HR) (95% CI) = 2.88 (1.42-5.85), P = 0.003; and reclassification, HR (95% CI) = 2.83 (1.40-5.74), P = 0.004. For rs7083961, the corresponding risk estimates were: D'Amico high versus low, odds ratio (95% CI) = 1.69 (1.12-2.57), P = 0.013; BCR, HR (95% CI) = 1.87 (1.15-3.02), P = 0.011 and reclassification, HR (95% CI) = 1.72 (1.09-2.72), P = 0.020. There were cumulative effects of these two SNPs on modulating these endpoints.

CONCLUSION

Genetic variants in EMT pathway may influence the risks of localized PCa's aggressiveness, BCR and disease reclassification, suggesting their potential role in the assessment and management of localized PCa.

Adherence to the Mediterranean diet and grade group progression in localized prostate cancer: An active surveillance cohort

BACKGROUND

The Mediterranean diet (MD) may be beneficial for men with localized prostate cancer (PCa) on active surveillance (AS) because of its anti-inflammatory, antilipidemic, and chemopreventive properties. This study prospectively investigated adherence to the MD with Gleason score progression and explored associations by diabetes status, statin use, and other factors.

METHODS

Men with newly diagnosed PCa on an AS protocol (n = 410) completed a baseline food frequency questionnaire, and the MD score was calculated across 9 energy-adjusted food groups. Cox proportional hazards models were fit to evaluate multivariable-adjusted associations of the MD score with progression-free survival; progression was defined as an increase in the Gleason grade group (GG) score over a biennial monitoring regimen.

RESULTS

In this cohort, 15% of the men were diabetic, 44% of the men used statins, and 76 men progressed (median follow-up, 36 months). After adjustments for clinical factors, higher adherence to the MD was associated with a lower risk of GG progression among all men (hazard ratio [HR] per 1-unit increase in MD score, 0.88; 95% confidence interval [CI], 0.77-1.01), non-White men (HR per 1-unit increase in MD score, 0.64; 95% CI, 0.45-0.92; P for interaction = .07), and men without diabetes (HR per 1-unit increase in MD score, 0.82; 95% CI, 0.71-0.96; P for interaction = .03). When joint effects of the MD score and statin use were examined, a similar risk reduction was observed among men with high MD scores who did not use statins in comparison with men with low/moderate MD scores with no statin use.

CONCLUSIONS

The MD is associated with a lower risk of GG progression in men on AS, and this is consistent with prior reports about the MD and reduced cancer morbidity and mortality.

The Association of Periprostatic Fat and Grade Group Progression in Men with Localized Prostate Cancer on Active Surveillance

PURPOSE

Evidence suggests that visceral fat quantity may be associated with post-prostatectomy outcomes and risk of prostate cancer related death. We evaluated whether increased fat volume, normalized to prostate size, is associated with decreased risk of disease progression.

MATERIALS AND METHODS

Patients enrolled on a prospective active surveillance trial for at least 6 months who had magnetic resonance imaging within 2 years of enrollment were eligible. The surveillance protocol included a standardized followup regimen consisting of biennial prostate specific antigen and examination and yearly biopsy. Clinicopathological characteristics were collected at baseline. Three fat measurements were taken using prostate magnetic resonance imaging, including subcutaneous, linear periprostatic (pubic symphysis to prostate) and volumetrically defined periprostatic. Progression was defined as increase in Gleason grade group. Multivariable Cox proportional hazards models were used to evaluate fat volumes normalized by prostate size (stratified into tertiles).

RESULTS

A total of 175 patients were included in the study. Average age was 62.5 years (SD 7.4) and average prostate specific antigen was 5.4 ng/dl (SD 3.9). Median followup was 42 months (IQR 18-60) and 50 patients (28.6%) had progression. Compared to the lowest tertile, the highest tertile of volumetric periprostatic fat measurement (HR 2.63, 95% CI 1.23-5.60, p=0.01) and linear periprostatic fat measurement (HR 2.30, 95% CI 1.01-5.22, p=0.05) were associated with worsened progression-free survival, while subcutaneous fat measurement (p=0.97) was not. Importantly, the model did not substantively change when accounting for patient body mass index and other factors.

CONCLUSIONS

Increased periprostatic fat volume, normalized to prostate size, may be associated with shortened progression-free survival in men with prostate cancer on active surveillance.

Association Between African American Race and Clinical Outcomes in Men Treated for Low-Risk Prostate Cancer With Active Surveillance

IMPORTANCE

There is concern that African American men with low-risk prostate cancer may harbor more aggressive disease than non-Hispanic White men. Therefore, it is unclear whether active surveillance is a safe option for African American men.

OBJECTIVE

To compare clinical outcomes of African American and non-Hispanic White men with low-risk prostate cancer managed with active surveillance.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study in the US Veterans Health Administration Health Care System of African American and non-Hispanic White men diagnosed with low-risk prostate cancer between January 1, 2001, and December 31, 2015, and managed with active surveillance. The date of final follow-up was March 31, 2020.

EXPOSURES

Active surveillance was defined as no definitive treatment within the first year of diagnosis and at least 1 additional surveillance biopsy.

MAIN OUTCOMES AND MEASURES

Progression to at least intermediate-risk, definitive treatment, metastasis, prostate cancer-specific mortality, and all-cause mortality.

RESULTS

The cohort included 8726 men, including 2280 African American men (26.1%) (median age, 63.2 years) and 6446 non-Hispanic White men (73.9%) (median age, 65.5 years), and the median follow-up was 7.6 years (interquartile range, 5.7-9.9; range, 0.2-19.2). Among African American men and non-Hispanic White men, respectively, the 10-year cumulative incidence of disease progression was 59.9% vs 48.3% (difference, 11.6% [95% CI, 9.2% to 13.9%); P < .001); of receipt of definitive treatment, 54.8% vs 41.4% (difference, 13.4% [95% CI, 11.0% to 15.7%]; P < .001); of metastasis, 1.5% vs 1.4% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .49); of prostate cancer-specific mortality, 1.1% vs 1.0% (difference, 0.1% [95% CI, -0.4% to 0.6%]; P = .82); and of all-cause mortality, 22.4% vs 23.5% (difference, 1.1% [95% CI, -0.9% to 3.1%]; P = 0.09).

CONCLUSIONS AND RELEVANCE

In this retrospective cohort study of men with low-risk prostate cancer followed up for a median of 7.6 years, African American men, compared with non-Hispanic White men, had a statistically significant increased 10-year cumulative incidence of disease progression and definitive treatment, but not metastasis or prostate cancer-specific mortality. Longer-term follow-up is needed to better assess the mortality risk.

Caveolin-1-mediated sphingolipid oncometabolism underlies a metabolic vulnerability of prostate cancer

Plasma and tumor caveolin-1 (Cav-1) are linked with disease progression in prostate cancer. Here we report that metabolomic profiling of longitudinal plasmas from a prospective cohort of 491 active surveillance (AS) participants indicates prominent elevations in plasma sphingolipids in AS progressors that, together with plasma Cav-1, yield a prognostic signature for disease progression. Mechanistic studies of the underlying tumor supportive onco-metabolism reveal coordinated activities through which Cav-1 enables rewiring of cancer cell lipid metabolism towards a program of 1) exogenous sphingolipid scavenging independent of cholesterol, 2) increased cancer cell catabolism of sphingomyelins to ceramide derivatives and 3) altered ceramide metabolism that results in increased glycosphingolipid synthesis and efflux of Cav-1-sphingolipid particles containing mitochondrial proteins and lipids. We also demonstrate, using a prostate cancer syngeneic RM-9 mouse model and established cell lines, that this Cav-1-sphingolipid program evidences a metabolic vulnerability that is targetable to induce lethal mitophagy as an anti-tumor therapy.

Determining Clinically Based Factors Associated With Reclassification in the Pre-MRI Era using a Large Prospective Active Surveillance Cohort

OBJECTIVE

To report biopsy-related and oncologic outcomes in a large prospective active surveillance cohort that was initiated in the premagnetic resonance imaging era and to additionally identify clinical factors associated with disease reclassification in order to inform future studies designed to improve enrollment and follow-up on active surveillance.

METHODS

Patients were prospectively enrolled at a single institution from 2006 to 2014 and followed until 2016. Men with Gleason 6 or 7 disease were eligible, and those with >6 months follow-up were included in the analysis. Patients were risk stratified based on clinical/pathologic criteria, including based on a combination of baseline and confirmatory biopsy tumor characteristics. Reclassification-free survival, based on tumor volume increase or Gleason score increase, was analyzed using multivariable Cox proportional hazards models.

RESULTS

Of 825 enrolled patients, 682 met inclusion criteria. Median follow-up was 40 months (range 6.6-126.8). Disease was reclassified in 249 (36.5%), and 157 (23.0%) underwent treatment. A single positive core with a negative confirmatory biopsy was significantly associated with time to reclassification (median not met vs 43 months, log rank test P <.001). Composite tumor length, defined as the combined tumor length between baseline and confirmatory biopsies, was associated with shorter Gleason upgrade-free survival (hazard ratio 1.24, 95% confidence interval 1.11-1.40, P <.001) in multivariable analysis.

CONCLUSION

Baseline stratification using clinical factors including tumor length may refine risk stratification and offer the foundation on which new systems that incorporate modalities such as magnetic resonance imaging may be based.

African American Race is Not Associated with Risk of Reclassification during Active Surveillance: Results from the Canary Prostate Cancer Active Surveillance Study

PURPOSE

In a large, prospective, multi-institutional active surveillance cohort we evaluated whether African American men are at higher risk for reclassification.

MATERIALS AND METHODS

The Canary PASS (Prostate Active Surveillance Study) is a protocol driven, active surveillance cohort with a prespecified prostate specific antigen and surveillance biopsy regimen. Men included in this study had Gleason Grade Group 1 or 2 disease at diagnosis and fewer than 5 years between diagnosis and enrollment, and had undergone 1 or more surveillance biopsies. The reclassification risk, defined as an increase in the Gleason score on subsequent biopsy, was compared between African American and Caucasian American men using Cox proportional hazards models. In the subset of men who underwent delayed prostatectomy the rate of adverse pathology findings, defined as pT3a or greater disease, or Gleason Grade Group 3 or greater, was compared in African American and Caucasian American men.

RESULTS

Of the 1,315 men 89 (7%) were African American and 1,226 (93%) were Caucasian American. There was no difference in the treatment rate in African American and Caucasian American men. In multivariate models African American race was not associated with the risk of reclassification (HR 1.16, 95% CI 0.78-1.72). Of the 441 men who underwent prostatectomy after a period of active surveillance the rate of adverse pathology was similar in those who were African American and Caucasian American (46% vs 47%, p=0.99).

CONCLUSIONS

Of men on active surveillance who followed a standardized protocol of regular prostate specific antigen testing and biopsy those who were African American were not at increased risk for pathological reclassification while on active surveillance, or for adverse pathology findings at prostatectomy. Active surveillance appears to be an appropriate management strategy for African American men with favorable risk prostate cancer.

Active surveillance for prostate and thyroid cancers: evolution in clinical paradigms and lessons learned

The adverse effects of overdiagnosis and overtreatment observed in men with clinically insignificant prostate cancers after the introduction of prostate-specific antigen-based screening are now being observed in those with thyroid cancer, owing to the introduction of new imaging technologies. Thus, the evolving paradigm of active surveillance in prostate and thyroid cancers might be valuable in informing the development of future active surveillance protocols. The lessons learned from active surveillance and their implications include the need to minimize the use of broad, population-based screening programmes that do not incorporate patient education and the need for individualized or shared decision-making, which can decrease the extent of overtreatment. Furthermore, from the experience in patients with prostate cancer, we have learned that consensus is required regarding the optimal selection of patients for active surveillance, using more-specific evidence-based methods for stratifying patients by risk. In this Review, we describe the epidemiology, pathology and screening guidelines for the management of patients with prostate and thyroid cancers; the evidence of overdiagnosis and overtreatment; and provide overviews of existing international active surveillance protocols.

Coffee, Caffeine Metabolism Genotype and Disease Progression in Patients with Localized Prostate Cancer Managed with Active Surveillance

PURPOSE

Active surveillance is increasingly used as a management strategy for localized prostate cancer. Coffee intake has been associated with a lower prostate cancer incidence. We assessed whether coffee was associated with disease progression in men on active surveillance.

MATERIALS AND METHODS

A total of 411 patients with newly diagnosed Gleason score 6 or 7 prostate cancer were enrolled on a prospective active surveillance protocol for at least 6 months and completed a baseline dietary assessment. The active surveillance protocol included a biennial monitoring regimen with disease progression defined as an increase in the Gleason score. Cox proportional hazards models were used to evaluate associations of coffee intake with progression-free survival. We also evaluated patient genotype in the caffeine metabolism related single nucleotide polymorphism rs762551.

RESULTS

Median followup was 36 months (range 6 to 126) and the Gleason score progressed in 76 of the 411 patients (18.5%). Compared to 0 cups per day, in the multivariable model adjusting for prostate specific antigen, patient age and tumor length, less than 1 cup (HR 0.85, 95% CI 0.40-1.71), 1 to 1.9 cups (HR 0.64, 95% CI 0.29-1.43), 2 to 3.9 cups (HR 0.71, 95% CI 0.35-1.47) and 4 cups or more (HR 1.67, 95% CI 0.81-3.45) were not significantly associated with progression-free survival (p for nonlinearity = 0.01). Patients with low/moderate coffee intake and the AA fast caffeine metabolizer genotype were less likely to experience grade progression than nonconsumers (HR 0.36, 95% CI 0.15-0.88, p = 0.03).

CONCLUSIONS

Low to moderate coffee intake appears safe in men on active surveillance of localized prostate cancer. Further work is needed to determine whether high consumption is associated with shorter progression-free survival in sensitive groups.

Diet quality and Gleason grade progression among localised prostate cancer patients on active surveillance

Background

High diet quality may support a metabolic and anti-inflammatory state less conducive to tumour progression. We prospectively investigated diet quality in relation to Gleason grade progression among localised prostate cancer patients on active surveillance, a clinical management strategy of disease monitoring and delayed intervention.

Methods

Men with newly diagnosed Gleason score 6 or 7 prostate cancer enroled on a biennial monitoring regimen. Patients completed a food frequency questionnaire (FFQ) at baseline (n = 411) and first 6-month follow-up (n = 263). Cox proportional hazards models were fitted to evaluate multivariable-adjusted associations of diet quality [defined via the Healthy Eating Index (HEI)-2015] with Gleason grade progression.

Results

After a median follow-up of 36 months, 76 men progressed. Following adjustment for clinicopathologic factors, we observed a suggestive inverse association between baseline diet quality and Gleason grade progression [hazard ratio (HR) and 95% confidence interval (CI) for the highest vs. the lowest HEI-2015 tertile: 0.59 (0.32–1.08); P_trend = 0.06]. We observed no associations with diet quality at 6-month follow-up, nor change in diet quality from baseline.

Conclusions

In localised prostate cancer patients on surveillance, higher diet quality or conformance with United States dietary guidelines at enrolment may lower risk of Gleason grade progression, though additional confirmatory research is needed.

Genetic associations of T cell cancer immune response with tumor aggressiveness in localized prostate cancer patients and disease reclassification in an active surveillance cohort

Determining prostate cancer (PCa) aggressiveness and reclassification are critical events during the treatment of localized disease and for patients undergoing active surveillance (AS). Since T cells play major roles in cancer surveillance and elimination, we aimed to identify genetic biomarkers related to T cell cancer immune response which are predictive of aggressiveness and reclassification risks in localized PCa. The genotypes of 3,586 single nucleotide polymorphisms (SNPs) from T cell cancer immune response pathways were analyzed in 1762 patients with localized disease and 393 who elected AS. The aggressiveness of PCa was defined according to pathological Gleason score (GS) and D'Amico criteria. PCa reclassification was defined according to changes in GS or tumor characteristics during subsequent surveillance biopsies. Functional characterization and analysis of immune phenotypes were also performed. In the localized PCa cohort, seven SNPs were significantly associated with the risk of aggressive disease. In the AS cohort, another eight SNPs were identified as predictors for aggressiveness and reclassification. Rs1687016 of PSMB8 was the most significant predictor of reclassification. Cumulative analysis showed that a genetic score based on the identified SNPs could significantly predict risk of D'Amico high risk disease (P-trend = 2.4E-09), GS4 + 3 disease (P-trend = 1.3E-04), biochemical recurrence (P-trend = 0.01) and reclassification (P-trend = 0.01). In addition, the rs34309 variant was associated with functional somatic mutations in the PI3K/PTEN/AKT/MTOR pathway and tumor lymphocyte infiltration. Our study provides plausible evidence that genetic variations in T cell cancer immune response can influence risks of aggressiveness and reclassification in localized PCa, which may lead to additional biological insight into these outcomes. Abbreviations: PCa, prostate cancer; AS, active surveillance; GS, Gleason score; PSA, prostate specific antigen; TCGA, The Cancer Genome Atlas; SNP, single nucleotide polymorphisms; UFG, unfavorable genotype.

Focal therapy for localized prostate cancer: is there a "middle ground" between active surveillance and definitive treatment?

In recent years, it has come a long way in the diagnosis, treatment, and follow-up of prostate cancer. Beside this, it was argued that definitive treatments could cause overtreatment, particularly in the very low, low, and favorable risk group. When alternative treatment and follow-up methods are being considered for this group of patients, active surveillance is seen as a good alternative for patients with very low and low-risk groups in this era. However, it has become necessary to find other alternatives for patients in the favorable risk group or patients who cannot adopt active follow-up. In the light of technological developments, the concept of focal therapy was introduced with the intensification of research to treat only the lesioned area instead of treating the entire organ for prostate lesions though there are not many publications about many of them yet. According to the initial results, it was understood that the results could be good if the appropriate focal therapy technique was applied to the appropriate patient. Thus, focal therapies have begun to find their "middle ground" place between definitive therapies and active follow-up.

Cost and efficacy comparison of five prostate biopsy modalities: a platform for integrating cost into novel-platform comparative research

BACKGROUND

The cornerstone of prostate cancer diagnosis remains the transrectal ultrasound-guided biopsy (TRUS-BX), which most frequently occurs in the office setting under local anesthesia. However, there are now other techniques of prostate biopsy aimed at improving outcomes such as patient comfort, significant cancer detection, and infectious complications. The purpose of the present study is to compare the cost and efficacy outcomes of five different approaches.

METHODS

We compared the comprehensive costs of a random sample size of 20-30 cases from each of the following: (1) local anesthesia TRUS-BX (reference), (2) sedation TRUS-BX, (3) general anesthesia transperineal template biopsy (TP), (4) sedation MRI-TRUS fusion biopsy (FB), and (5) sedation in-bore MRI biopsy (IB-MRI). Cost categories included pre-procedure, anesthesia pharmacy and recovery, and the technical/professional costs from urology, radiology, and pathology services. For procedure outcomes, we compared the larger cohorts of TRUS-BX, TP, and FB in terms of indication, cancer yield, and downstream decision impact.

RESULTS

Compared with standard TRUS-BX, the total costs of sedation TRUS-BX, TP, FB, and IB-MRI increased significantly ×1.9 (90%), ×2.5 (153%), ×2.5 (150%), and ×2.2 (125%), respectively (p < 0.001). Although there was no statistical difference between the total costs of TP, FB, and IB-MRI, these costs were significantly higher than those of TRUS-BX under either local anesthesia or sedation (p < 0.05). The cost of TRUS-BX under sedation was significantly higher than that of TRUS-BX under local anesthesia (p < 0.001). Compared to TRUS-BX, more significant cancers were detected in FB (16% vs. 36%) and TP (16% vs. 34%) groups (p < 0.001).

CONCLUSIONS

Compared with standard TRUS-BX, the additions of imaging, sedation anesthesia, and transperineal template increase costs significantly, and can be considered along with known improvements in accuracy and side effects. Ongoing efforts to combine imaging and transperineal biopsy, especially in an outpatient/local anesthesia setting may lead to a higher cost/benefit.

Baseline and longitudinal plasma caveolin-1 level as a biomarker in active surveillance for early-stage prostate cancer

OBJECTIVES

To evaluate the role of caveolin-1 (Cav-1) as a predictor of disease reclassification (DR) in men with early prostate cancer undergoing active surveillance (AS).

PATIENTS AND METHODS

We analysed archived plasma samples prospectively collected from patients with early prostate cancer in a single-institution AS study. Of 825 patients enrolled, 542 had ≥1 year of follow-up. Baseline and longitudinal plasma Cav-1 levels were measured using an enzyme-linked immunosorbent assay. Tumour volume or Gleason grade increases were criteria for DR. Logistic regression analyses were used to assess associations between clinicopathological characteristics and reclassification risk.

RESULTS

In 542 patients, 480 (88.6%) had stage cT1c disease, 542 (100.0%) had a median prostate-specific antigen level of 4.1 ng/mL, and 531 (98.0%) had a median Cancer of the Prostate Risk Assessment score of 1. In all, 473 (87.3%) had a Gleason score of 3+3. After a median of 3.1 years of follow-up, disease was reclassified in 163 patients (30.1%). The mean baseline Cav-1 level was 2.2 ± 8.5 ng/mL and the median 0.2 ng/mL (range, 0-85.5 ng/mL). In univariate analysis, baseline Cav-1 was a significant predictor for risk of DR (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.24-2.65; P = 0.002). In multivariate analysis, with adjustments for age, tumour length, group risk stratification and number of positive cores, reclassification risk associated with Cav-1 remained significant (OR 1.91, 95% CI 1.28-2.84; P = 0.001).

CONCLUSION

Baseline plasma Cav-1 level was an independent predictor of disease classification. New methods for refining AS and intervention may result.

Risk score predicts high-grade prostate cancer in DNA-methylation positive, histopathologically negative biopsies

BACKGROUND

Prostate cancer (PCa) diagnosis is challenging because efforts for effective, timely treatment of men with significant cancer typically result in over-diagnosis and repeat biopsies. The presence or absence of epigenetic aberrations, more specifically DNA-methylation of GSTP1, RASSF1, and APC in histopathologically negative prostate core biopsies has resulted in an increased negative predictive value (NPV) of ∼90% and thus could lead to a reduction of unnecessary repeat biopsies. Here, it is investigated whether, in methylation-positive men, DNA-methylation intensities could help to identify those men harboring high-grade (Gleason score ≥7) PCa, resulting in an improved positive predictive value.

METHODS

Two cohorts, consisting of men with histopathologically negative index biopsies, followed by a positive or negative repeat biopsy, were combined. EpiScore, a methylation intensity algorithm was developed in methylation-positive men, using area under the curve of the receiver operating characteristic as metric for performance. Next, a risk score was developed combining EpiScore with traditional clinical risk factors to further improve the identification of high-grade (Gleason Score ≥7) cancer.

RESULTS

Compared to other risk factors, detection of DNA-methylation in histopathologically negative biopsies was the most significant and important predictor of high-grade cancer, resulting in a NPV of 96%. In methylation-positive men, EpiScore was significantly higher for those with high-grade cancer detected upon repeat biopsy, compared to those with either no or low-grade cancer. The risk score resulted in further improvement of patient risk stratification and was a significantly better predictor compared to currently used metrics as PSA and the prostate cancer prevention trial (PCPT) risk calculator (RC). A decision curve analysis indicated strong clinical utility for the risk score as decision-making tool for repeat biopsy.

CONCLUSIONS

Low DNA-methylation levels in PCa-negative biopsies led to a NPV of 96% for high-grade cancer. The risk score, comprising DNA-methylation intensity and traditional clinical risk factors, improved the identification of men with high-grade cancer, with a maximum avoidance of unnecessary repeat biopsies. This risk score resulted in better patient risk stratification and significantly outperformed current risk prediction models such as PCPTRC and PSA. The risk score could help to identify patients with histopathologically negative biopsies harboring high-grade PCa. Prostate 76:1078-1087, 2016. © 2016 The Authors. The Prostate Published by Wiley Periodicals, Inc.

Genetic variants of the Wnt signaling pathway as predictors of aggressive disease and reclassification in men with early stage prostate cancer on active surveillance

Little is known about the genetic predictors of prostate cancer aggressiveness and reclassification in men with localized prostate cancer undergoing active surveillance. The Wnt signaling pathway is important for prostate cancer development and progression. Identifying genetic variants associated with prostate cancer aggressiveness and reclassification may have a potential role in the management of localized patients. In this study, we used a three-phase design. In phases I and II prostate cancer patient cohort, 578 single nucleotide polymorphisms (SNPs) from 45 genes of the Wnt signaling pathway were analyzed in 1762 localized prostate cancer patients. Twelve SNPs from four regions were significantly associated with aggressive disease, among which, three linked SNPs in CSNK1A1 at 5q32 (represented by rs752822) may differentiate GS 4+3 from GS 3+4 patients (OR = 1.44, 95% CI = 1.12-1.87, P = 4.76×10(-3)). In phase III active surveillance (AS) cohort, genotyping of rs752822 (candidate from phases I and II) and previously identified rs2735839 were determined in 494 GS ≤7 patients. We found a significant association between rs2735839 and prostate cancer reclassification in the AS cohort (AG + AA versus GG, HR = 1.59, 95% CI = 1.11-2.28, P = 0.012) and a suggestive association of rs752822. Jointly, rs752822 and rs2735839 showed good potentials in risk-stratifying GS 7 patients and predicting disease reclassification (OR = 2.71, 95% CI = 1.62-4.51, P = 1×10(-4) in phase II; HR = 1.89, 95% CI = 1.13-3.18, P = 0.016 in phase III). In summary, rs752822 and rs2735839 may assist in risk-stratifying GS 7 patients and predict prostate cancer reclassification. The significant associations were independent from GS, T stage and PSA levels at baseline.

The implications of ageing and life expectancy in prostate cancer treatment

In patients diagnosed with prostate cancer, the selection of treatment, including the type of therapy and its aggressiveness, is often based on a patient's age and life expectancy. Life expectancy estimates are too often calculated solely on the patient's chronological age, overlooking comorbid conditions and their severity, which can greatly affect life expectancy. If, in addition to chronological age, comorbid conditions are used to assess a patient's life expectancy, the most appropriate treatment options are more likely to be selected. Older, healthy patients might be able to tolerate more aggressive treatment than would be administered on the basis of their age alone, and younger patients with numerous comorbid conditions could avoid harsh therapy that might not be appropriate given their current state of health. The key idea to consider in treatment selection is what a patient's quality of life would be like with or without a particular treatment option. In an era of precision medicine, decisions regarding the provision of health care should be made rationally and on the basis of objective estimates of the threat of disease and the benefits and costs of intervention and within the context of the patient's characteristics and desires.

[Active surveillance for low-risk prostate cancer]

Autopsy studies have confirmed the high prevalence of latent prostate cancer; however, only a certain portion of patients require definite treatment. Active surveillance is one of the treatment options which, according to national and international guidelines, should be offered to patients with newly diagnosed low-risk prostate cancer. Prostate cancer-specific survival is high in these patients; therefore, curative treatment, such as radical prostatectomy, external beam radiotherapy and brachytherapy may be initially deferred in order to avoid therapy-related side effects. In order to qualify for active surveillance, strict inclusion criteria have to be met; nevertheless, the reliable identification of low-risk prostate cancer patients is not always possible. Patients under active surveillance are followed up regularly with prostate-specific antigen (PSA) testing, digital rectal examination (DRE) and repeat prostate biopsies. Due to the heterogeneity of primary prostate tumors precise molecular diagnostic techniques could allow individualized treatment strategies in the future.