The watchman

Long-Term Outcomes in Patients Using Protocol-Directed Active Surveillance for Prostate Cancer

Importance

Outcomes from protocol-directed active surveillance for favorable-risk prostate cancers are needed to support decision-making.

Objective

To characterize the long-term oncological outcomes of patients receiving active surveillance in a multicenter, protocol-directed cohort.

Design, Setting, and Participants

The Canary Prostate Active Surveillance Study (PASS) is a prospective cohort study initiated in 2008. A cohort of 2155 men with favorable-risk prostate cancer and no prior treatment were enrolled at 10 North American centers through August 2022.

Exposure

Active surveillance for prostate cancer.

Main Outcomes and Measures

Cumulative incidence of biopsy grade reclassification, treatment, metastasis, prostate cancer mortality, overall mortality, and recurrence after treatment in patients treated after the first or subsequent surveillance biopsies.

Results

Among 2155 patients with localized prostate cancer, the median follow-up was 7.2 years, median age was 63 years, 83% were White, 7% were Black, 90% were diagnosed with grade group 1 cancer, and median prostate-specific antigen (PSA) was 5.2 ng/mL. Ten years after diagnosis, the incidence of biopsy grade reclassification and treatment were 43% (95% CI, 40%-45%) and 49% (95% CI, 47%-52%), respectively. There were 425 and 396 patients treated after confirmatory or subsequent surveillance biopsies (median of 1.5 and 4.6 years after diagnosis, respectively) and the 5-year rates of recurrence were 11% (95% CI, 7%-15%) and 8% (95% CI, 5%-11%), respectively. Progression to metastatic cancer occurred in 21 participants and there were 3 prostate cancer-related deaths. The estimated rates of metastasis or prostate cancer-specific mortality at 10 years after diagnosis were 1.4% (95% CI, 0.7%-2%) and 0.1% (95% CI, 0%-0.4%), respectively; overall mortality in the same time period was 5.1% (95% CI, 3.8%-6.4%).

Conclusions and Relevance

In this study, 10 years after diagnosis, 49% of men remained free of progression or treatment, less than 2% developed metastatic disease, and less than 1% died of their disease. Later progression and treatment during surveillance were not associated with worse outcomes. These results demonstrate active surveillance as an effective management strategy for patients diagnosed with favorable-risk prostate cancer.

Effects of Androgen Deprivation Therapy on Prostate Cancer Outcomes According to Competing Event Risk: Secondary Analysis of a Phase 3 Randomised Trial

BACKGROUND

Previous studies indicate that the benefit of short-term androgen deprivation therapy (ADT) with radiotherapy (RT) for prostate cancer depends on competing risks.

OBJECTIVE

To determine whether a quantitative method to stratify patients by risk for competing events (omega score) could identify subgroups that selectively benefit from ADT.

DESIGN, SETTING, AND PARTICIPANTS

An ancillary analysis of NRG/RTOG 9408 phase 3 trial (NCT00002597) involving 1945 prostate cancer patients was conducted.

INTERVENTION

Short-term ADT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We applied generalised competing event regression models incorporating age, performance status, comorbidity, T category, Gleason score (GS), and prostate-specific antigen (PSA), to stratify patients according to relative hazards for primary cancer-related events (distant metastasis or prostate cancer death) versus competing noncancer mortality. We tested interactions between ADT and subgroups defined by standard risk criteria versus relative risk (RR) using the omega score.

RESULTS AND LIMITATIONS

T2b, higher GS, and higher PSA were associated with an increased RR for cancer-related versus competing mortality events (a higher omega score); increased age and comorbidity were associated with a decreased omega score. Of 996 patients with low-risk/favourable intermediate-risk (FIR) disease, 286 (28.7%) had a high omega score (≥0.314). Of 768 patients with unfavourable intermediate-risk disease, 175 (22.8%) had a low omega score. The overall discordance in risk classification was 26.1%. Both standard criteria and omega score identified significant interactions for the effect of ADT on cancer-related events and late mortality in low- versus high-risk subgroups. Within the low-risk/FIR subgroup, a higher omega score identified patients in whom ADT significantly reduced cancer events and improved event-free survival. Limitations are the need for external/prospective validation and lower RT doses than contemporary standards.

CONCLUSIONS

Stratification based on competing event risk is useful for identifying prostate cancer patients who selectively benefit from ADT.

PATIENT SUMMARY

We analysed the effectiveness of androgen deprivation therapy (ADT) for localised prostate cancer among patients, defined by the relative risk (RR) for cancer versus noncancer events. Among patients with traditional low-risk/favourable intermediate-risk disease, those with a higher RR benefitted from short-term ADT.

National Trends in Management of Newly Diagnosed Prostate Cancer

BACKGROUND

Deciding whether to treat or conservatively manage patients with prostate cancer is challenging. Recent changes in guidelines, advances in treatment technologies, and policy can influence decision making surrounding management, particularly for those for whom the decision to treat is discretionary. Contemporary trends in management of newly diagnosed prostate cancer are unclear.

METHODS

Using national Medicare data, men with newly diagnosed prostate cancer were identified between 2014 and 2019. Patients were classified by 5- and 10-year noncancer mortality risk. Multinomial logistic regression models were fit to assess adjusted trends in management over time. The primary outcome was management of prostate cancer: local treatment (inclusive of surgery, radiation, brachytherapy, or cryotherapy), hormone therapy, or observation.

RESULTS

Local treatment was the most common form of management and stable across years (68%). Use of observation increased (21%-23%, P < .001) and use of hormone therapy decreased (11%-8%, P < 0.001). After stratifying by 10-year non-cancer mortality risk, observation increased among men with low (22.3%-26.1%, P < .001) and moderate (19.9%-23.5%, P < .001) mortality risk. Conversely, use of treatment increased among those with high (62.8%-68.0%, P = .004) and very high (45.5%-54.1%, P < .001) risk of noncancer mortality. These trends were similar across groups when stratified by 5-year noncancer mortality risk.

CONCLUSION

Nationally, use of local treatment remains common and was stable throughout the study period. However, while local treatment declined among men with a lower risk of noncancer mortality, it increased among men with a higher risk of non-cancer mortality.

Perceived barriers to the adoption of active surveillance in low-risk prostate cancer: a qualitative analysis of community and academic urologists

BACKGROUND

Clinical practice guidelines recommend active surveillance as the preferred treatment option for low-risk prostate cancer, but only a minority of eligible men receive active surveillance, and practice variation is substantial. The aim of this study is to describe barriers to urologists' recommendation of active surveillance in low-risk prostate cancer and explore variation of barriers by setting.

METHODS

We conducted semi-structured interviews among 22 practicing urologists, evenly distributed between academic and community practice. We coded barriers to active surveillance according to a conceptual model of determinants of treatment quality to identify potential opportunities for intervention.

RESULTS

Community and academic urologists were generally in agreement on factors influencing active surveillance. Urologists perceived patient-level factors to have the greatest influence on recommendations, particularly tumor pathology, patient age, and judgements about the patient's ability to adhere to follow-up protocols. They also noted cross-cutting clinical barriers, including concerns about the adequacy of biopsy samples, inconsistent protocols to guide active surveillance, and side effects of biopsy procedures. Urologists had differing opinions on the impact of environmental factors, such as financial disincentives and fear of litigation.

CONCLUSIONS

Despite national and international recommendations, both academic and community urologists note a variety of barriers to implementing active surveillance in low risk prostate cancer. These barriers will need to be specifically addressed in efforts to help urologists offer active surveillance more consistently.

Navigate: a study protocol for a randomised controlled trial of an online treatment decision aid for men with low-risk prostate cancer and their partners

BACKGROUND

Active surveillance (AS) is the disease management option of choice for low-risk prostate cancer. Despite this, men with low-risk prostate cancer (LRPC) find management decisions distressing and confusing. We developed Navigate, an online decision aid to help men and their partners make management decisions consistent with their values. The aims are to evaluate the impact of Navigate on uptake of AS; decision-making preparedness; decisional conflict, regret and satisfaction; quality of illness communication; and prostate cancer-specific quality of life and anxiety. In addition, the healthcare cost impact, cost-effectiveness and patterns of use of Navigate will be assessed. This paper describes the study protocol.

METHODS

Three hundred four men and their partners are randomly assigned one-to-one to Navigate or to the control arm. Randomisation is electronically generated and stratified by site. Navigate is an online decision aid that presents up-to-date, unbiased information on LRPC tailored to Australian men and their partners including each management option and potential side-effects, and an interactive values clarification exercise. Participants in the control arm will be directed to the website of Australia's peak national body for prostate cancer. Eligible patients will be men within 3 months of being diagnosed with LRPC, aged 18 years or older, and who are yet to make a treatment decision, who are deemed eligible for AS by their treating clinician and who have Internet access and sufficient English to participate. The primary outcome is self-reported uptake of AS as the first-line management option. Secondary outcomes include self-reported preparedness for decision-making; decisional conflict, regret and satisfaction; quality of illness communication; and prostate cancer-specific quality of life. Uptake of AS 1 month after consent will be determined through patient self-report. Men and their partners will complete study outcome measures before randomisation and 1, 3 and 6 months after study consent.

DISCUSSION

The Navigate online decision aid has the potential to increase the choice of AS in LRPC, avoiding or delaying unnecessary radical treatments and associated side effects. In addition, Navigate is likely to reduce patients' and partners' confusion and distress in management decision-making and increase their quality of life.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trial Registry ACTRN12616001665426 . Registered on 2 December 2016. All items from the WHO Trial Registration Data set can be found in this manuscript.

Study protocol: a lifestyle intervention for African American and Hispanic prostate cancer survivors on active surveillance and their partners

Background

Prostate cancer is the most commonly diagnosed cancer in both African American and Hispanic men. Active surveillance is a treatment option for low- or very low-risk prostate cancer survivors, and lifestyle interventions have been found to reduce the disease progression and improve the quality of life for both survivors and their partners. To date, no lifestyle interventions that specifically target African American or Hispanic men and their partners exist. This protocol describes a study that tests the feasibility of a randomized controlled trial, a lifestyle intervention developed to enhance healthy lifestyle and quality of life among African American and Hispanic men on active surveillance and their partners.

Methods

A mixed-method study, including a two-arm randomized controlled trial (n = 30 dyads in the intervention arm and n = 10 dyads in the control arm) and in-depth interviews, will be conducted. Intervention arm participants will receive bi-weekly health coaching calls (a total of 12 calls based on Motivational Interviewing), as well as physical activity-specific (e.g., power point slides, print materials about physical activity, and activity trackers for self-monitoring) and nutrition-specific education (e.g., two nutrition counseling sessions from a registered dietitian, print materials about nutrition, and food intake recording for self-monitoring) over 6 months. All participants will be assessed at baseline, month 3, and month 6. Blood will be collected at baseline and month 6 from the prostate cancer survivors. Finally, in-depth interviews will be conducted with subsamples (up to n = 15 dyads in the intervention arm and up to n = 5 dyads in the control arm) at baseline and months 3 and 6 to conduct a process evaluation and further refine the intervention.

Discussion

If effective, the intervention may have a higher health impact compared with a typical lifestyle intervention targeting only survivors (or partners), as it improves both survivors’ (tertiary prevention) and partners’ health (primary prevention). Results from this study will provide important information regarding recruiting racial/ethnic minority cancer survivors and their partners. Lessons learned from this study will be used to apply for a large-scale grant to test the impact of the dyadic intervention in a fully powered sample.

Trial registration

ClinicalTrials.gov (NCT No. 03575832) registered on 3 July 2018.

Utilization of Multiparametric MRI of Prostate in Patients under Consideration for or Already in Active Surveillance: Correlation with Imaging Guided Target Biopsy

This study sought to assess the value of multiparametric magnetic resonance image (mp-MRI) in patients with a prostate cancer (PCa) Gleason score of 6 or less under consideration for or already in active surveillance and to determine the rate of upgrading by target biopsy. Three hundred and fifty-four consecutive men with an initial transrectal ultrasound-guided (TRUS) biopsy-confirmed PCa Gleason score of 6 or less under clinical consideration for or already in active surveillance underwent mp-MRI and were retrospectively reviewed. One hundred and nineteen of 354 patients had cancer-suspicious regions (CSRs) at mp-MRI. Each CSR was assigned a Prostate Imaging Reporting and Data System (PI-RADS) score based on PI-RADS v2. One hundred and eight of 119 patients underwent confirmatory imaging-guided biopsy for CSRs. Pathology results including Gleason score (GS) and percentage of specimens positive for PCa were recorded. Associations between PI-RADS scores and findings at target biopsy were evaluated using logistic regression. At target biopsy, 81 of 108 patients had PCa (75%). Among them, 77 patients had upgrading (22%, 77 of 354 patients). One hundred and forty-six CSRs in 108 patients had PI-RADS 3 n = 28, 4 n = 66, and 5 n = 52. The upgraded rate for each category of CSR was for PI-RADS 3 (5 of 28, 18%), 4 (47 of 66, 71%) and 5 (49 of 52, 94%). Using logistic regression analysis, differences in PI-RADS scores from 3 to 5 are significantly associated with the probability of disease upgrade (20%, 73%, and 96% for PI-RADS score of 3, 4, and 5, respectively). Adding mp-MRI to patients under consideration for or already in active surveillance helps to identify undiagnosed PCa of a higher GS or higher volume resulting in upgrading in 22%.

17-Gene Genomic Prostate Score Test Results in the Canary Prostate Active Surveillance Study (PASS) Cohort

PURPOSE

The 17-gene Oncotype DX Genomic Prostate Score (GPS) test predicts adverse pathology (AP) in patients with low-risk prostate cancer treated with immediate surgery. We evaluated the GPS test as a predictor of outcomes in a multicenter active surveillance cohort.

MATERIALS AND METHODS

Diagnostic biopsy tissue was obtained from men enrolled at 8 sites in the Canary Prostate Active Surveillance Study. The primary endpoint was AP (Gleason Grade Group [GG] ≥ 3, ≥ pT3a) in men who underwent radical prostatectomy (RP) after initial surveillance. Multivariable regression models for interval-censored data were used to evaluate the association between AP and GPS. Inverse probability of censoring weighting was applied to adjust for informative censoring. Predictiveness curves were used to evaluate how models stratified risk of AP. Association between GPS and time to upgrade on surveillance biopsy was evaluated using Cox proportional hazards models.

RESULTS

GPS results were obtained for 432 men (median follow-up, 4.6 years); 101 underwent RP after a median 2.1 years of surveillance, and 52 had AP. A total of 167 men (39%) upgraded at a subsequent biopsy. GPS was significantly associated with AP when adjusted for diagnostic GG (hazards ratio [HR]/5 GPS units, 1.18; 95% CI, 1.04 to 1.44; P = .030), but not when also adjusted for prostate-specific antigen density (PSAD; HR, 1.85; 95% CI, 0.99 to 4.19; P = .066). Models containing PSAD and GG, or PSAD, GG, and GPS may stratify risk better than a model with GPS and GG. No association was observed between GPS and subsequent biopsy upgrade (P = .48).

CONCLUSION

In our study, the independent association of GPS with AP after initial active surveillance was not statistically significant, and there was no association with upgrading in surveillance biopsy. Adding GPS to a model containing PSAD and diagnostic GG did not significantly improve stratification of risk for AP over the clinical variables alone.

Elevated Tumor Lactate and Efflux in High-grade Prostate Cancer demonstrated by Hyperpolarized 13C Magnetic Resonance Spectroscopy of Prostate Tissue Slice Cultures

Non-invasive assessment of the biological aggressiveness of prostate cancer (PCa) is needed for men with localized disease. Hyperpolarized (HP) ¹³C magnetic resonance (MR) spectroscopy is a powerful approach to image metabolism, specifically the conversion of HP [1-¹³C]pyruvate to [1-¹³C]lactate, catalyzed by lactate dehydrogenase (LDH). Significant increase in tumor lactate was measured in high-grade PCa relative to benign and low-grade cancer, suggesting that HP ¹³C MR could distinguish low-risk (Gleason score ≤3 + 4) from high-risk (Gleason score ≥4 + 3) PCa. To test this and the ability of HP ¹³C MR to detect these metabolic changes, we cultured prostate tissues in an MR-compatible bioreactor under continuous perfusion. ³¹P spectra demonstrated good viability and dynamic HP ¹³C-pyruvate MR demonstrated that high-grade PCa had significantly increased lactate efflux compared to low-grade PCa and benign prostate tissue. These metabolic differences are attributed to significantly increased LDHA expression and LDH activity, as well as significantly increased monocarboxylate transporter 4 (MCT4) expression in high- versus low- grade PCa. Moreover, lactate efflux, LDH activity, and MCT4 expression were not different between low-grade PCa and benign prostate tissues, indicating that these metabolic alterations are specific for high-grade disease. These distinctive metabolic alterations can be used to differentiate high-grade PCa from low-grade PCa and benign prostate tissues using clinically translatable HP [1-¹³C]pyruvate MR.

Why men with a low-risk prostate cancer select and stay on active surveillance: A qualitative study

Objective

Active surveillance (AS) is an increasingly utilized strategy for monitoring men with low-risk prostate cancer (PCa) that allows them to defer active treatment (AT) in the absence of cancer progression. Studies have explored reasons for selecting AS and for then switching to AT, but less is known about men’s experiences being on AS. We interviewed men to determine the clinical and psychological factors associated with selecting and adhering to AS protocols.

Methods

We conducted semi-structured interviews with men with a low-risk PCa at two academic medical centers. Subjects had either been on AS for ≥ 1 year or had opted for AT after a period of AS. We used an iterative, content-driven approach to analyze the interviews and to identify themes.

Results

We enrolled 21 subjects, mean age 70.4 years, 3 racial/ethnic minorities, and 16 still on AS. Men recognized the favorable prognosis of their cancer (some had sought second opinions when initially offered AT), valued avoiding treatment complications, were reassured that close monitoring would identify progression early enough to be successfully treated, and trusted their urologists. Although men reported feeling anxious around the time of surveillance testing, those who switched to AT did so based only on evidence of cancer progression.

Conclusions

Our selected sample was comfortable being on AS because they understood and valued the rationale for this approach. However, this highlights the importance of ensuring that men newly diagnosed with a low-risk PCa are provided sufficient information about prognosis and treatment options to make informed decisions.

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.

Performance of PCA3 and TMPRSS2:ERG urinary biomarkers in prediction of biopsy outcome in the Canary Prostate Active Surveillance Study (PASS)

BACKGROUND

For men on active surveillance for prostate cancer, biomarkers may improve prediction of reclassification to higher grade or volume cancer. This study examined the association of urinary PCA3 and TMPRSS2:ERG (T2:ERG) with biopsy-based reclassification.

METHODS

Urine was collected at baseline, 6, 12, and 24 months in the multi-institutional Canary Prostate Active Surveillance Study (PASS), and PCA3 and T2:ERG levels were quantitated. Reclassification was an increase in Gleason score or ratio of biopsy cores with cancer to ≥34%. The association of biomarker scores, adjusted for common clinical variables, with short- and long-term reclassification was evaluated. Discriminatory capacity of models with clinical variables alone or with biomarkers was assessed using receiver operating characteristic (ROC) curves and decision curve analysis (DCA).

RESULTS

Seven hundred and eighty-two men contributed 2069 urine specimens. After adjusting for PSA, prostate size, and ratio of biopsy cores with cancer, PCA3 but not T2:ERG was associated with short-term reclassification at the first surveillance biopsy (OR = 1.3; 95% CI 1.0-1.7, p = 0.02). The addition of PCA3 to a model with clinical variables improved area under the curve from 0.743 to 0.753 and increased net benefit minimally. After adjusting for clinical variables, neither marker nor marker kinetics was associated with time to reclassification in subsequent biopsies.

CONCLUSIONS

PCA3 but not T2:ERG was associated with cancer reclassification in the first surveillance biopsy but has negligible improvement over clinical variables alone in ROC or DCA analyses. Neither marker was associated with reclassification in subsequent biopsies.

Offsetting Expression Profiles of Prognostic Markers in Prostate Tumor vs. Its Microenvironment

Diagnosis of the presence of tumors and subsequent prognosis based on tumor microenvironment becomes more clinically practical because tumor-adjacent tissues are easy to collect and they are more genetically homogeneous. The purpose of this study was to identify new prognostic markers in prostate stroma that are near the tumor. We have demonstrated the prognostic features of FGFR1, FRS2, S6K1, LDHB, MYPT1, and P-LDHA in prostate tumors using tissue microarrays (TMAs) which consist of 241 patient samples from Massachusetts General Hospital (MGH). In this study, we investigated these six markers in the tumor microenvironment using an Aperio Imagescope system in the same TMAs. The joint prognostic power of markers was further evaluated and classified using a new algorithm named Weighted Dichotomizing. The classifier was verified via rigorous 10-fold cross validation. Statistical analysis of the protein expression indicated that in tumor-adjacent stroma FGFR1 and MYPT1 were significantly correlated with patient outcomes and LDHB showed the outcome-association tendency. More interestingly, these correlations were completely opposite regarding tumor tissue as previously reported. The results suggest that prognostic testing should utilize either tumor-enriched tissue or stroma with distinct signature profiles rather than using mixture of both tissue types. The new classifier based on stroma tissue has potential value in the clinical management of prostate cancer patients.

Randomized trial evaluating the role of weight loss in overweight and obese men with early stage prostate Cancer on active surveillance: Rationale and design of the Prostate Cancer Active Lifestyle Study (PALS)

Active surveillance (AS) is increasingly used to monitor patients with low-risk prostate cancer; however, approximately 50% of AS patients experience disease reclassification requiring definitive treatment and little is known about patient characteristics that modify the risk of reclassification. Obesity may be one of the major contributing factors. The Prostate Cancer Active Lifestyle Study (PALS) is a clinical trial evaluating the impact of weight loss among overweight/obese (Body Mass Index (BMI) ≥ 25 kg/m2) men with clinically localized prostate cancer on AS. Two hundred participants will be randomized to either the PALS intervention, a 6-month structured diet and exercise program adapted from the Diabetes Prevention Program followed by 6 months of maintenance, or control (general diet and physical activity guidelines delivered in a single session). The PALS intervention involves one-on-one instruction with a registered dietitian and exercise physiologist to achieve the study goal of loss of 7% of baseline weight. Participation is coordinated so that the 6-month time point coincides with the participants' standard-of-care AS prostate biopsy. Primary outcomes will evaluate the intervention effects on circulating and tissue markers of glucose and insulin regulation, health-related quality of life and pathologic upgrading on follow-up prostate biopsies. Additional analyses will determine whether changes in weight and glucose regulation can be sustained for 6 months after the end of instruction. Findings from this trial may have wide reaching implications for men diagnosed with clinically-localized prostate cancer by providing an active lifestyle-based approach to improve prostate cancer patient outcomes.

The Quality of Life among Men Receiving Active Surveillance for Prostate Cancer: An Integrative Review

Prostate cancer is very common among men in the United States. The current literature on active surveillance (AS) suggests that it is a promising treatment option for men with low-risk prostate cancer. The purpose of this manuscript is to provide a thorough integrative review regarding the effects of AS on the quality of life (QoL) of men with prostate cancer. Utilizing a methodological strategy, electronic databases were reviewed for empirical articles during the time frame of January 2006 to December 2016. A total of 37 articles met the inclusion criteria wherein 20 focused on the QoL among men only receiving AS and 16 reported QoL among men undergoing AS and other forms of treatment for prostate cancer. The review highlights the purpose, common instruments, race and ethnicity, and strengths and limitations of each article. The majority of articles indicated low levels of anxiety and depression and decreased incidences of bladder, bowel and sexual functioning among men undergoing AS in comparison to men who received other treatment modalities. The results indicated that additional research is needed to determine the QoL among men receiving AS on a longitudinal basis. The results support previous literature that indicated the positive impact of AS on low-risk prostate cancer.

The Diverse Genomic Landscape of Clinically Low-risk Prostate Cancer

BACKGROUND

Among men with clinically low-risk prostate cancer, we have previously documented heterogeneity in terms of clinical characteristics and genomic risk scores.

OBJECTIVE

To further study the underlying tumor biology of this patient population, by interrogating broader patterns of gene expression among men with clinically low-risk tumors.

DESIGN, SETTING, AND PARTICIPANTS

Prostate biopsies from 427 patients considered potentially suitable for active surveillance underwent central pathology review and genome-wide expression profiling. These cases were compared with 1290 higher-risk biopsy cases with diverse clinical features from a prospective genomic registry.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Average genomic risk (AGR) was determined from 18 published prognostic signatures, and MSigDB hallmark gene sets were analyzed using bootstrapped clustering methods. These sets were examined in relation to clinical variables and pathological and biochemical outcomes using multivariable regression analysis.

RESULTS AND LIMITATIONS

A total of 408 (96%) biopsies passed RNA quality control. Based on AGR quartiles defined by the high-risk multicenter cases, the University of California, San Francisco (UCSF) low-risk patients were distributed across the quartiles as 219 (54%), 107 (26%), 61 (15%), and 21 (5%). Unsupervised clustering analysis of the hallmark gene set scores revealed three clusters, which were enriched for the previously described PAM50 luminal A, luminal B, and basal subtypes. AGR, but not the clusters, was associated with both pathological (odds ratio 1.34, 95% confidence interval [CI] 1.14-1.58) and biochemical outcomes (hazard ratio 1.53, 95% CI 1.19-1.93). These results may underestimate within-prostate genomic heterogeneity.

CONCLUSIONS

Prostate cancers that are homogeneously low risk by traditional characteristics demonstrate substantial diversity at the level of genomic expression. Molecular substratification of low-risk prostate cancer will yield a better understanding of its divergent biology and, in the future may help personalize treatment recommendations.

PATIENT SUMMARY

We studied the genomic characteristics of tumors from men diagnosed with low-risk prostate cancer. We found three main subtypes of prostate cancer with divergent tumor biology, similar to what has previously been found in women with breast cancer. In addition, we found that genomic risk scores were associated with worse pathology findings and prostate-specific antigen recurrence after surgery. These results suggest even greater genomic diversity among low-risk patients than has previously been documented with more limited signatures.

The Movember Foundation's GAP3 cohort: a profile of the largest global prostate cancer active surveillance database to date

OBJECTIVES

The Movember Foundation launched the Global Action Plan Prostate Cancer Active Surveillance (GAP3) initiative to create a global consensus on the selection and monitoring of men with low-risk prostate cancer (PCa) on active surveillance (AS). The aim of this study is to present data on inclusion and follow-up for AS in this unique global AS database.

PATIENTS AND METHODS

Between 2014 and 2016, the database was created by combining patient data from 25 established AS cohorts worldwide (USA, Canada, Australasia, UK and Europe). Data on a total of 15 101 patients were included. Descriptive statistics were used to report patients' clinical and demographic characteristics at the time of PCa diagnosis, clinical follow-up, discontinuation of AS and subsequent treatment. Cumulative incidence curves were used to report discontinuation rates over time.

RESULTS

At diagnosis, the median (interquartile range [IQR]) patient age was 65 (60-70) years and the median prostate-specific antigen level was 5.4 (4.0-7.3) ng/mL. Most patients had clinical stage T1 disease (71.8%), a biopsy Gleason score of 6 (88.8%) and one tumour-positive biopsy core (60.3%). Patients on AS had a median follow-up time of 2.2 (1.0-5.0) years. After 5, 10 and 15 years of follow-up, respectively, 58%, 39% and 23% of patients were still on AS. The current version of GAP3 has limited data on magnetic resonance imaging (MRI), quality of life and genomic testing.

CONCLUSIONS

GAP3 is the largest worldwide collaboration integrating patient data from men with PCa on AS. The results will allow individual patients and clinicians to have greater confidence in the personalized decision to either delay or proceed with active treatment. Longer follow-up and the evaluation of MRI, new genomic markers and patient-related outcomes will result in even more valuable data and eventually in better patient outcomes.

Active Surveillance Versus Watchful Waiting for Localized Prostate Cancer: A Model to Inform Decisions

BACKGROUND

An increasing proportion of prostate cancer is being managed conservatively. However, there are no randomized trials or consensus regarding the optimal follow-up strategy.

OBJECTIVE

To compare life expectancy and quality of life between watchful waiting (WW) versus different strategies of active surveillance (AS).

DESIGN, SETTING, AND PARTICIPANTS

A Markov model was created for US men starting at age 50, diagnosed with localized prostate cancer who chose conservative management by WW or AS using different testing protocols (prostate-specific antigen every 3-6 mo, biopsy every 1-5 yr, or magnetic resonance imaging based). Transition probabilities and utilities were obtained from the literature.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary outcomes were life years and quality-adjusted life years (QALYs). Secondary outcomes include radical treatment, metastasis, and prostate cancer death.

RESULTS AND LIMITATIONS

All AS strategies yielded more life years compared with WW. Lifetime risks of prostate cancer death and metastasis were, respectively, 5.42% and 6.40% with AS versus 8.72% and 10.30% with WW. AS yielded more QALYs than WW except in cohorts age >65 yr at diagnosis, or when treatment-related complications were long term. The preferred follow-up strategy was also sensitive to whether people value short-term over long-term benefits (time preference). Depending on the AS protocol, 30-41% underwent radical treatment within 10 yr. Extending the surveillance biopsy interval from 1 to 5 yr reduced life years slightly, with a 0.26 difference in QALYs.

CONCLUSIONS

AS extends life more than WW, particularly for men with higher-risk features, but this is partly offset by the decrement in quality of life since many men eventually receive treatment.

PATIENT SUMMARY

More intensive active surveillance protocols extend life more than watchful waiting, but this is partly offset by decrements in quality of life from subsequent treatment.

Best practice guidance for the use of strategies to improve retention in randomized trials developed from two consensus workshops

Objectives

To develop best practice guidance for the use of retention strategies in randomized clinical trials (RCTs).

Study Design and Setting

Consensus development workshops conducted at two UK Clinical Trials Units. Sixty-six statisticians, clinicians, RCT coordinators, research scientists, research assistants, and data managers associated with RCTs participated. The consensus development workshops were based on the consensus development conference method used to develop best practice for treatment of medical conditions. Workshops commenced with a presentation of the evidence for incentives, communication, questionnaire format, behavioral, case management, and methodological retention strategies identified by a Cochrane review and associated qualitative study. Three simultaneous group discussions followed focused on (1) how convinced the workshop participants were by the evidence for retention strategies, (2) barriers to the use of effective retention strategies, (3) types of RCT follow-up that retention strategies could be used for, and (4) strategies for future research. Summaries of each group discussion were fed back to the workshop. Coded content for both workshops was compared for agreement and disagreement. Agreed consensus on best practice guidance for retention was identified.

Results

Workshop participants agreed best practice guidance for the use of small financial incentives to improve response to postal questionnaires in RCTs. Use of second-class post was thought to be adequate for postal communication with RCT participants. The most relevant validated questionnaire was considered best practice for collecting RCT data. Barriers identified for the use of effective retention strategies were: the small improvements seen in questionnaire response for the addition of monetary incentives, and perceptions among trialists that some communication strategies are outdated. Furthermore, there was resistance to change existing retention practices thought to be effective. Face-to-face and electronic follow-up technologies were identified as retention strategies for further research.

Conclusions

We developed best practice guidance for the use of retention strategies in RCTs and identified potential barriers to the use of effective strategies. The extent of agreement on best practice is limited by the variability in the currently available evidence. This guidance will need updating as new retention strategies are developed and evaluated.

Is suspicious upstaging on multiparametric magnetic resonance imaging useful in improving the reliability of Prostate Cancer Research International Active Surveillance (PRIAS) criteria? Use of the K-CaP registry

BACKGROUND AND OBJECTIVE

To evaluate the clinical effects of suspicious upstaging on multiparametric magnetic resonance imaging (mpMRI) for improving the quality of Prostate Cancer Research International Active Surveillance (PRIAS) criteria.

MATERIAL AND METHODS

A total of 363 patients with low-risk prostate cancer (PCa) were selected from the K-CaP registry (the multicenter Korean PCa Database). Patients were divided into 2 groups according to the results of mpMRI (with or without suspicious upstaging). The variables for predicting significant PCa, defined as locally advanced PCa, Gleason score≥7, or tumor volume>0.5cc or all of these, and adverse PCa, defined as locally advanced PCa, Gleason score≥7 (4+3), or tumor volume>2.5cc or all of these, were assessed.

RESULTS

The mpMRI led to "suspicious" upstaging in 56 patients (15.4%). Significant PCa (98.2% vs. 74.6%, P<0.001) and adverse PCa (85.7% vs. 32.6%, P<0.001) were more common in patients with suspicious upstaging. The sensitivity/specificity of mpMRI for significant PCa and adverse PCa were 25.4%/98.2% and 32.4%/96.3%, respectively. On multivariate analyses, suspicious upstaging on mpMRI (odds ratio: 15.82, P = 0.007) was a predictor for significant PCa in addition to PRIAS criteria and age at diagnosis. In addition, suspicious upstaging on mpMRI (odds ratio: 11.11, P<0.001) was a significant predictor for adverse PCa in addition to PRIAS criteria, age at diagnosis, and body mass index.

CONCLUSION

Along with the PRIAS criteria, suspicious upstaging on mpMRI is a potent diagnostic tool for distinguishing patients suitable for active surveillance among patients with low-risk PCa.

Qualitative study on decision-making by prostate cancer physicians during active surveillance

OBJECTIVE

To explore and identify factors that influence physicians' decisions while monitoring patients with prostate cancer on active surveillance (AS).

SUBJECTS AND METHODS

A purposive sampling strategy was used to identify physicians treating prostate cancer from diverse clinical backgrounds and geographic areas across the USA. We conducted 24 in-depth interviews from July to December 2015, until thematic saturation was reached. The Applied Thematic Analysis framework was used to guide data collection and analysis. Interview transcripts were reviewed and coded independently by two researchers. Matrix analysis and NVivo software were used for organization and further analysis.

RESULTS

Eight key themes emerged to explain variation in AS monitoring: (i) physician comfort with AS; (ii) protocol selection; (iii) beliefs about the utility and quality of testing; (iv) years of experience and exposure to AS during training; (v) concerns about inflicting 'harm'; (vi) patient characteristics; (vii) patient preferences; and (viii) financial incentives.

CONCLUSION

These qualitative data reveal which factors influence physicians who manage patients on AS. There is tension between providing standardized care while also considering individual patients' needs and health status. Additional education on AS is needed during urology training and continuing medical education. Future research is needed to empirically understand whether any specific protocol is superior to tailored, individualized care.

Emerging minimally invasive procedures for focal treatment of organ-confined prostate cancer

Prostate cancer is the most common malignancy amongst American men. However, the majority of prostate cancer diagnoses are of low risk, organ-confined disease. Many men elect to undergo definitive treatment, but may benefit from focal therapy to maintain continence and potency. This review reports the mechanism of action and outcomes of emerging focal therapies for prostate cancer. We report the mechanism of action of focal cryotherapy, high intensity focused ultrasound, focal laser ablation, and irreversible electroporation. In addition, we reviewed the largest studies available reporting rates of urinary incontinence, erectile dysfunction, biochemical recurrence-free survival (ASTRO), and post-operative adverse events for each procedure. Each treatment modality stated has a unique mechanism in the ablation of cancerous cells. Genito-urinary symptoms following these studies report incontinence and erectile dysfunction rates ranging from 0-15% and 0-53%, respectively. Biochemical disease-free survival was reported using the ASTRO definition. Some treatment modalities lack the necessary follow-up to determine effectiveness in cancer control. No focal therapy studies reported serious adverse events. These minimally invasive procedures are feasible in a clinical setting and show promising functional and disease control results with short to medium-term follow-up. However, each treatment requires additional robust prospective studies as well as its own unique domain to determine biochemical recurrence free survival to properly determine their role in treatment of organ-confined prostate cancer.

Targeted proteomics identifies liquid-biopsy signatures for extracapsular prostate cancer

Biomarkers are rapidly gaining importance in personalized medicine. Although numerous molecular signatures have been developed over the past decade, there is a lack of overlap and many biomarkers fail to validate in independent patient cohorts and hence are not useful for clinical application. For these reasons, identification of novel and robust biomarkers remains a formidable challenge. We combine targeted proteomics with computational biology to discover robust proteomic signatures for prostate cancer. Quantitative proteomics conducted in expressed prostatic secretions from men with extraprostatic and organ-confined prostate cancers identified 133 differentially expressed proteins. Using synthetic peptides, we evaluate them by targeted proteomics in a 74-patient cohort of expressed prostatic secretions in urine. We quantify a panel of 34 candidates in an independent 207-patient cohort. We apply machine-learning approaches to develop clinical predictive models for prostate cancer diagnosis and prognosis. Our results demonstrate that computationally guided proteomics can discover highly accurate non-invasive biomarkers.

Proteomic technologies are capable of identifying thousands of proteins in biological samples, but biomarker applications are lagging. Here the authors use Multiple Reaction Monitoring Mass Spectrometry to delineate peptide signatures that accurately distinguish between defined prostate cancer patient risk groups.

Treatment Preferences for Active Surveillance versus Active Treatment among Men with Low-Risk Prostate Cancer

BACKGROUND

Due to the concerns about the overtreatment of low-risk prostate cancer, active surveillance (AS) is now a recommended alternative to the active treatments (AT) of surgery and radiotherapy. However, AS is not widely utilized, partially due to psychological and decision-making factors associated with treatment preferences.

METHODS

In a longitudinal cohort study, we conducted pretreatment telephone interviews (N = 1,140, 69.3% participation) with newly diagnosed, low-risk prostate cancer patients (PSA ≤ 10, Gleason ≤ 6) from Kaiser Permanente Northern California. We assessed psychological and decision-making variables, and treatment preference [AS, AT, and No Preference (NP)].

RESULTS

Men were 61.5 (SD, 7.3) years old, 24 days (median) after diagnosis, and 81.1% white. Treatment preferences were: 39.3% AS, 30.9% AT, and 29.7% NP. Multinomial logistic regression revealed that men preferring AS (vs. AT) were older (OR, 1.64; CI, 1.07-2.51), more educated (OR, 2.05; CI, 1.12-3.74), had greater prostate cancer knowledge (OR, 1.77; CI, 1.43-2.18) and greater awareness of having low-risk cancer (OR, 3.97; CI, 1.96-8.06), but also were less certain about their treatment preference (OR, 0.57; CI, 0.41-0.8), had greater prostate cancer anxiety (OR, 1.22; CI, 1.003-1.48), and preferred a shared treatment decision (OR, 2.34; CI, 1.37-3.99). Similarly, men preferring NP (vs. AT) were less certain about treatment preference, preferred a shared decision, and had greater knowledge.

CONCLUSIONS

Although a substantial proportion of men preferred AS, this was associated with anxiety and uncertainty, suggesting that this may be a difficult choice.

IMPACT

Increasing the appropriate use of AS for low-risk prostate cancer will require additional reassurance and information, and reaching men almost immediately after diagnosis while the decision-making is ongoing. Cancer Epidemiol Biomarkers Prev; 25(8); 1240-50. ©2016 AACR.

Sociodemographic and Clinical Predictors of Switching to Active Treatment among a Large, Ethnically Diverse Cohort of Men with Low Risk Prostate Cancer on Observational Management

PURPOSE

We determined the clinical and sociodemographic predictors of beginning active treatment in an ethnically diverse population of men with low risk prostate cancer initially on observational treatment.

MATERIALS AND METHODS

We retrospectively studied men diagnosed with low risk prostate cancer between 2004 and 2012 at Kaiser Permanente Northern California who did not receive any treatment within the first year of diagnosis and had at least 2 years of followup. We used Cox proportional hazards regression models to determine factors associated with time from diagnosis to active treatment.

RESULTS

We identified 2,228 eligible men who were initially on observation, of whom 27% began active treatment during followup at a median of 2.9 years. NonHispanic black men were marginally more likely to begin active treatment than nonHispanic white men independent of baseline and followup clinical measures (HR 1.3, 95% CI 1.0-1.7). Among men who remained on observation nonHispanic black men were rebiopsied within 24 months of diagnosis at a slightly lower rate than nonHispanic white men (HR 0.70, 95% CI 0.6-1.0). Gleason grade progression (HR 3.3, 95% CI 2.7-4.1) and PSA doubling time less than 48 months (HR 2.9, 95% CI 2.3-3.7) were associated with initiation of active treatment independent of race.

CONCLUSIONS

Sociodemographic factors such as ethnicity and education may independently influence the patient decision to pursue active treatment and serial biopsies during active surveillance. These factors are important for further studies of prostate cancer treatment decision making.

Radiotherapy planning using MRI

The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.

The Significance of Accurate Determination of Gleason Score for Therapeutic Options and Prognosis of Prostate Cancer

The Gleason score (GS) to date remains one of the most reliable prognostic predictors in prostate cancer (PCa). However, the majority of studies supporting its prognostic relevance were performed prior to its modification by the International Society of Urological Pathology (ISUP) in 2005. Furthermore, the combination of Gleason grading and nuclear/nucleolar subgrading (Helpap score) has been shown to essentially improve grading concordance between biopsy and radical prostatectomy (RP) specimens. This prompted us to investigate the modified GS and combigrading (Gleason/Helpap score) in association with clinicopathological features, biochemical recurrence (BCR), and survival. Core needle biopsies and corresponding RP specimens from 580 patients diagnosed with PCa between 2005 and 2010 were evaluated. According to the modified GS, the comparison between biopsy and RP samples resulted in an upgrading from GS 6 to GS 7a and GS 7b in 65% and 19%, respectively. Combigrading further resulted in an upgrading from low grade (GS 6/2a) to intermediate grade PCa (GS 6/2b) in 11.1% and from intermediate grade (GS 6/2b) to high grade PCa (GS 7b/2b) in 22.6%. Overall, well-differentiated PCa (GS 6/2a) was detected in 2.8% of RP specimens, while intermediate grade (GS 6/2b and GS 7a/2b) and high grade cancers (≥ GS 7b) accounted for 39.5% and 57.4% of cases, respectively. At a mean follow-up of 3.9 years, BCR was observed in 17.6% of patients with intermediate (9.8%) or high grade PCa (30.2%), while PSA relapse did not occur in GS 6/2a PCa. In conclusion, adding nuclear/nucleolar subgrading to the modified GS allowed for a more accurate distinction between low and intermediate grade PCa, therefore offering a valuable tool for the identification of patients eligible for active surveillance (AS).

Fifteen-year Outcomes Following Conservative Management Among Men Aged 65 Years or Older with Localized Prostate Cancer

BACKGROUND

To understand the threat posed by localized prostate cancer and the potential impact of surgery or radiation, patients and healthcare providers require information on long-term outcomes following conservative management.

OBJECTIVE

To describe 15-yr survival outcomes and cancer therapy utilization among men 65 years and older managed conservatively for newly diagnosed localized prostate cancer.

DESIGN, SETTINGS, AND PARTICIPANTS

This is a population-based cohort study with participants living in predefined geographic areas covered by the Surveillance, Epidemiology, and End Results program. The study includes 31 137 Medicare patients aged ≥65 yr diagnosed with localized prostate cancer in 1992-2009 who initially received conservative management (no surgery, radiotherapy, cryotherapy, or androgen deprivation therapy [ADT]). All patients were followed until death or December 31, 2009 (for prostate cancer-specific mortality [PCSM]) and December 31, 2011 (for overall mortality).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Competing-risk analyses were used to examine PCSM, overall mortality, and utilization of cancer therapies.

RESULTS AND LIMITATIONS

The 15-yr risk of PCSM for men aged 65-74 yr diagnosed with screening-detected prostate cancer was 5.7% (95% confidence interval [CI] 3.7-8.0%) for T1c Gleason 5-7 and 22% (95% CI 16-35%) for Gleason 8-10 disease. After 15 yr of follow-up, 24% (95% CI 21-27%) of men aged 65-74 yr with screening-detected Gleason 5-7 cancer received ADT. The corresponding result for men with Gleason 8-10 cancer was 38% (95% CI 32-44%). The major study limitations are the lack of data for men aged <65 yr and detailed clinical information associated with secondary cancer therapy.

CONCLUSIONS

The 15-yr outcomes following conservative management of newly diagnosed Gleason 5-7 prostate cancer among men aged ≥65 yr are excellent. Men with Gleason 8-10 disease managed conservatively face a significant risk of PCSM.

PATIENT SUMMARY

We examined the long-term survival outcomes for a large group of patients diagnosed with localized prostate cancer who did not have surgery, radiotherapy, cryotherapy, or androgen deprivation therapy in the first 6 mo after cancer diagnosis. We found that the 15-yr disease-specific survival is excellent for men diagnosed with Gleason 5-7 disease. The data support conservative management as a reasonable choice for elderly patients with low-grade localized prostate cancer.

An Increase in Gleason 6 Tumor Volume While on Active Surveillance Portends a Greater Risk of Grade Reclassification with Further Followup

PURPOSE

We evaluated the relative risk of later grade reclassification and outcomes of patients in whom high volume Gleason 6 prostate cancer develops while on active surveillance.

MATERIALS AND METHODS

A prospectively maintained database was used to identify patients on active surveillance between 1998 and 2013. Tumor volume was assessed based on the number of positive cores and proportion of core involvement. The chi-square and Fisher exact tests were used for analysis as appropriate. The primary end point was the development of grade reclassification, defined as grade only and/or grade and volume at the event biopsy.

RESULTS

A total of 555 men met the study inclusion criteria. Mean followup was 46 months. Overall 70 patients demonstrated an increase in tumor volume at or after biopsy 2. Compared to those men never experiencing volume or grade reclassification, prostate specific antigen at diagnosis was not significantly different (p=0.95), but median prostate volume was smaller in patients who demonstrated volume reclassification (p <0.001). The incidence of pure volume reclassification was 6.8%, 6.1% and 7.8% at biopsy 2, 3 and 4, respectively. Men with volume reclassification were more likely to experience later grade reclassification than those without at 33.3% vs 9.3%, respectively (p <0.0001).

CONCLUSIONS

While Gleason 6 prostate cancer has a favorable natural history, it appears that patients on active surveillance who experience volume reclassification are at substantially higher risk for grade reclassification. Thus, urologists should pay close attention to tumor core involvement, and monitoring should be adjusted accordingly for early volume reclassification in younger men and those in good health.

Intermediate and Longer-Term Outcomes From a Prospective Active-Surveillance Program for Favorable-Risk Prostate Cancer

PURPOSE

To assess long-term outcomes of men with favorable-risk prostate cancer in a prospective, active-surveillance program.

METHODS

Curative intervention was recommended for disease reclassification to higher cancer grade or volume on prostate biopsy. Primary outcomes were overall, cancer-specific, and metastasis-free survival. Secondary outcomes were the cumulative incidence of reclassification and curative intervention. Factors associated with grade reclassification and curative intervention were evaluated in a Cox proportional hazards model.

RESULTS

A total of 1,298 men (median age, 66 years) with a median follow-up of 5 years (range, 0.01 to 18.00 years) contributed 6,766 person-years of follow-up since 1995. Overall, cancer-specific, and metastasis-free survival rates were 93%, 99.9%, and 99.4%, respectively, at 10 years and 69%, 99.9%, and 99.4%, respectively, at 15 years. The cumulative incidence of grade reclassification was 26% at 10 years and was 31% at 15 years; cumulative incidence of curative intervention was 50% at 10 years and was 57% at 15 years. The median treatment-free survival was 8.5 years (range, 0.01 to 18 years). Factors associated with grade reclassification were older age (hazard ratio [HR], 1.03 for each additional year; 95% CI, 1.01 to 1.06), prostate-specific antigen density (HR, 1.21 per 0.1 unit increase; 95% CI, 1.12 to 1.46), and greater number of positive biopsy cores (HR, 1.47 for each additional positive core; 95% CI, 1.26 to 1.69). Factors associated with intervention were prostate-specific antigen density (HR, 1.38 per 0.1 unit increase; 95% CI, 1.22 to 1.56) and a greater number of positive biopsy cores (HR, 1.35 for one additional positive core; 95% CI, 1.19 to 1.53).

CONCLUSION

Men with favorable-risk prostate cancer should be informed of the low likelihood of harm from their diagnosis and should be encouraged to consider surveillance rather than curative intervention.

Prostate MRI can reduce overdiagnosis and overtreatment of prostate cancer

The contemporary management of prostate cancer (PCa) has been criticized as fostering overdetection and overtreatment of indolent disease. In particular, the historical inability to identify those men with an elevated PSA who truly warrant biopsy, and, for those needing biopsy, to localize aggressive tumors within the prostate, has contributed to suboptimal diagnosis and treatment strategies. This article describes how modern multi-parametric MRI of the prostate addresses such challenges and reduces both overdiagnosis and overtreatment. The central role of diffusion-weighted imaging (DWI) in contributing to MRI's current impact is described. Prostate MRI incorporating DWI achieves higher sensitivity than standard systematic biopsy for intermediate-to-high risk tumor, while having lower sensitivity for low-grade tumors that are unlikely to impact longevity. Particular applications of prostate MRI that are explored include selection of a subset of men with clinical suspicion of PCa to undergo biopsy as well as reliable confirmation of only low-risk disease in active surveillance patients. Various challenges to redefining the standard of care to incorporate solely MRI-targeted cores, without concomitant standard systematic cores, are identified. These include needs for further technical optimization of current systems for performing MRI-targeted biopsies, enhanced education and expertise in prostate MRI among radiologists, greater standardization in prostate MRI reporting across centers, and recognition of the roles of pre-biopsy MRI and MRI-targeted biopsy by payers. Ultimately, it is hoped that the medical community in the United States will embrace prostate MRI and MRI-targeted biopsy, allowing all patients with known or suspected prostate cancer to benefit from this approach.

Are biomarkers evaluated in biopsy specimens predictive of prostate cancer aggressiveness?

PURPOSE

To evaluate biomarkers involved in biological pathways for prostate cancer (PCa) progression, measured in biopsy specimens, in order to distinguish patients at higher risk for fatal PCa and thus improve the initial management of disease.

METHODS

Retrospective case-control study. In 129 PCa patients who underwent ultrasound-guided needle prostate biopsy and subsequent radical prostatectomy from 1987 to 1999 at the University Hospital of Careggi, we evaluated: (1) mRNA expression of the serine 2 (TMPRSS2): erythroblastosis virus E26 oncogene homolog (ERG); (2) expression of matrix metalloproteinases (MMP)-2 and 9 (epithelial and stromal); (3) expression of androgen receptor; (4) expression of prognostic marker Ki67 (MIB1); (5) presence and typing of human papilloma virus; (6) DNA methylation of CpG islands of several genes involved in PCa progression.

RESULTS

The cohort consists of 38 cases (patients with PCa and died of PCa within 10 years from diagnosis) and 91 controls (patients with PCa but alive 10 years after diagnosis). Gleason bioptic score, epithelial MMP expression and SERPINB5 methylation correlated with statistically significant increase in death risk OR. Compared with patients with high level of MMP, patients with low level of MMP had OR for specific death 4.78 times higher (p = 0.0066). After adjustment for age and Gleason score, none of the investigated biomarkers showed increased OR for PCa death.

CONCLUSIONS

Our preliminary results suggest that evaluation, in prostate biopsy specimens, of a panel of biomarkers known to be involved in PCa progression is poorly indicative of tumor outcome.

Recepteur d'origine nantais (RON), more than a kinase: Role in castrate-resistant prostate cancer

Prostate cancer (PCA) is the second leading cause of cancer-related deaths in men in the United States. It is natural for a hormone-driven malignancy such as prostate cancer that androgen deprivation therapy (ADT) would be the preferred treatment for clinical disease management. However, after initial treatment response a vast majority of patients develop metastatic castrate-resistant prostate cancer (CRPC), which is fatal. While great headway has been made to understand the possible mechanisms that drive castrate-resistant disease, a bonafide cure remains elusive. Reactivation of androgen receptor (AR) signaling partly contributes to the emergence of CRPC. Here we briefly examine some of the known mechanisms of AR reactivation including intratumoral synthesis of androgens, modulation of AR coregulators, and AR variants with constitutive activity as well as activation of receptor tyrosine kinases. We primarily focus on the emerging dual function of the receptor tyrosine kinase (recepteur d'origine nantais; RON) as a traditional tyrosine kinase and transcription factor. We further discuss activation of RON as an alternate mechanism in the development of CRPC and available therapeutic approaches for clinical management of CRPC by combined inhibition of RON and AR.