Comparing Prostate Specific Antigen Triggers for Intervention in Men With Stable Prostate Cancer on Active Surveillance

Clinical Implications of Basic Research: Exploring the Transformative Potential of Spatial 'Omics in Uro-oncology

New spatial molecular technologies are poised to transform our understanding and treatment of urological cancers. By mapping the spatial molecular architecture of tumours, these platforms uncover the complex heterogeneity within and around individual malignancies, offering novel insights into disease development, progression, diagnosis, and treatment. They enable tracking of clonal phylogenetics in situ and immune-cell interactions in the tumour microenvironment. A whole transcriptome/genome/proteome-level spatial analysis is hypothesis generating, particularly in the areas of risk stratification and precision medicine. Current challenges include reagent costs, harmonisation of protocols, and computational demands. Nonetheless, the evolving landscape of the technology and evolving machine learning applications have the potential to overcome these barriers, pushing towards a future of personalised cancer therapy, leveraging detailed spatial cellular and molecular data. PATIENT SUMMARY: Tumours are complex and contain many different components. Although we have been able to observe some of these differences visually under the microscope, until recently, we have not been able to observe the genetic changes that underpin cancer development. Scientists are now able to explore molecular/genetic differences using approaches such as "spatial transcriptomics" and "spatial proteomics", which allow them to see genetic and cellular variation across a region of normal and cancerous tissue without destroying the tissue architecture. Currently, these technologies are limited by high associated costs, and a need for powerful and complex computational analysis workflows. Future advancements and results through these new technologies may assist patients and their doctors as they make decisions about treating their cancer.

Association Between Oncotype DX Genomic Prostate Score and Adverse Tumor Pathology After Radical Prostatectomy

BACKGROUND

The Oncotype DX assay is a clinically validated 17-gene genomic assay that provides a genomic prostate score (GPS; scale 0-100) measuring the heterogeneous nature of prostate tumors. The test is performed on prostate tissue collected during biopsy. There is a lack of data on the association between the GPS and tumor pathology after radical prostatectomy (RP).

OBJECTIVE

To investigate the association between GPS and final pathology, including extraprostatic extension (EPE), positive surgical margin (PSM), and seminal vesicle invasion (SVI).

DESIGN, SETTING, AND PARTICIPANTS

Data for the 749 patients who underwent Oncotype DX assay and RP at a referral prostate cancer center between 2015 and 2019 were retrospectively assessed to evaluate the association between GPS and unfavorable pathology parameters.

INTERVENTION

After a GPS genetic test, patients underwent robotic RP performed by the same surgeon.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable logistic regression analyses were performed to assess the association between GPS and EPE, PSM, and SVI. The models were adjusted for age, clinical stage, prostate-specific antigen (PSA) level, Gleason score, and time between the genomic assay and surgery. The median time between Oncotype DX assay and surgery was 176 d (interquartile range [IQR] 141-226). The median age was 63 yr (IQR 58-68), median GPS was 29 (IQR 21-39), and median PSA was 5.7 ng/ml (IQR 4.6-7.7). In multivariable analyses assessing the odds ratio (OR) per 20-point change in GPS, GPS was an independent predictor of EPE (OR 1.8, 95% confidence interval [CI] 1.4-2.3) and SVI (OR 2.1, 95% CI 1.3-3.4). In addition, when patients were grouped by GPS quartile, the percentage of cases with EPE and SVI increased with the GPS quartile.

CONCLUSIONS

We provide evidence that the Oncotype DX GPS is significantly associated with adverse pathology after RP. Specifically, the risk of EPE and SVI increases with the GPS. Therefore, use of the Oncotype DX GPS may help clinicians to improve preoperative patient counseling and develop surgical strategies for patients with a higher chance of EPE or unfavorable pathological features.

PATIENT SUMMARY

We studied whether the score for a prostate genetic test was associated with prostate cancer pathology findings for patients who had their prostate removed. We found that the risk of prostate cancer spread outside the gland and to the seminal vesicle increases with higher test scores. These findings may help surgeons in counseling patients on surgical options for prostate cancer.

Influence of Sociodemographic Factors on Definitive Intervention Among Low-risk Active Surveillance Patients

OBJECTIVES

To investigate sociodemographic factors influencing decision of initially active surveillance (AS) prostate cancer (CaP) patients to opt for definitive therapy, and, specifically, choice of radical prostatectomy (RP) versus radiation therapy (XRT).

METHODS

The Surveillance, Epidemiology, and End Results (SEER) Prostate with Watchful Waiting database was used to identify AS patients diagnosed with NCCN low-risk CaP between 2010 and 2015. We sought to determine predictors of treatment type using multivariable logistic regression analyses.

RESULTS

Out of 32,874 men included, 21,255 (64.7%) underwent delayed treatment, with 3,751 (17.6%) and 17,463 (82.2%) opting for RP and XRT, respectively. Patients who were married (Odds Ratio [OR]: 1.18, P <.001), insured (OR 2.94, P <.001), of higher socioeconomic status (OR 1.67 for highest vs lowest, P <.01), and residing in a Southeastern or Midwestern region (ORs 1.26 and 1.22 vs Northeast, respectively, P <.01) were significantly more likely to undergo definitive intervention. A significant interaction between patient race and marital/socioeconomic statuses on the decision-making process was identified. Decision for XRT (vs RP) was more likely in older (OR 11.6 for 70-79 vs 50-59 years, P <.01), unmarried (OR 1.89, P <.01), African American (OR 1.41, P .018), and higher socioeconomic status (OR 1.54 for highest versus lowest quartile, P <.01) patients.

CONCLUSION

The majority of patients initially treated with AS underwent delayed treatment. After accounting for pathologic characteristics, the interaction of sociodemographic factors including race, socioeconomic status, marital status, insurance status, and region of residence are significantly associated with the likelihood of undergoing definitive therapy.

Update and optimization of active surveillance in prostate cancer in 2021

INTRODUCTION AND OBJECTIVES

Within the paradigm shift of the last decade in the management of prostate cancer (PCa), perhaps the most relevant event has been the emergence of active surveillance (AS) as a mandatory strategy in low-risk disease. We carry out a critical review of the clinical, pathological and radiological improvements that allow optimizing AS in 2021.

MATERIAL AND METHODS

Critical narrative review of the literature on improvement issues and controversial aspects of AS.

RESULTS

Adequate use of traditional criteria, optimized by enhanced biopsy and calculation of the prostate volume technique thanks to multiparametric magnetic resonance imaging (mpMRI) allow a better selection of patients for AS. This management should not be limited to patients under 60years of age, and patients with intermediate-risk PCa should be carefully selected to be included. Biopsies are still required in the follow-up, which can be personalized according to risk patterns. The pathologist must identify the cribriform or intraductal histology on biopsies in order to exclude these patients from AS, in the same way as with patients with alterations in DNA repair genes.

CONCLUSIONS

Controversial indications such as the inclusion of patients from intermediate-risk groups, or the transition to active treatment due to exclusive progression in tumor volume, should be further optimized. It is possible that the future competition of tissue biomarkers, the refinement of objective parameters of mpMRI and the validation of PSA kinetics calculators may sub-stratify risk groups.

Contemporary approach to active surveillance for favorable risk prostate cancer

The approach to favorable risk prostate cancer known as “active surveillance” was first described explicitly in 2002. This was a report of 250 patients managed with a strategy of expectant management, with serial prostate-specific antigen and periodic biopsy, and radical intervention advised for patients who were re-classified as higher risk. This was initiated as a prospective clinical trial, complete with informed consent, beginning in 2007. Thus, there are now 20 years of experience with this approach, which has become widely adopted around the world. In this chapter, we will summarize the biological basis for active surveillance, review the experience to date of the Toronto and Hopkins groups which have reported 15-year outcomes, describe the current approach to active surveillance in patients with Gleason score 3 + 3 or selected patients with Gleason score 3 + 4 with a low percentage of Gleason pattern 4 who may also be candidates, enhanced by the use of magnetic resonance imaging, and forecast future directions.

Active surveillance for low-risk prostate cancer

PURPOSE OF REVIEW

The approach of active surveillance for low-risk prostate cancer has evolved in many ways since its introduction 20 years ago. There is a great deal of ongoing research addressing the molecular genetics and clinical outcome of low-risk disease, the use of MRI and biomarkers, and the role of lifestyle and dietary modifications. The major developments in the field are reviewed in this article.

RECENT FINDINGS

Low risk and many cases of low-intermediate risk prostate cancer are indolent, have little or no metastatic potential, and do not pose a threat to the patient in his lifetime. These are termed clinically insignificant. Studies over the last 20 years have advanced our understanding of who these patients are, and promoted the use of conservative management in such individuals. A key component of this approach is the early identification of those patients who have been misattributed as having low-risk disease, who in fact harbor higher risk disease and are likely to benefit from definitive therapy. This represents about 30% of newly diagnosed low-risk patients. A further small proportion of patients with low-risk disease demonstrate biological progression to higher grade disease. Extent of Gleason 6 on biopsy, Prostate Specific Antigen density, and race are predictors for the likelihood of coexistent higher grade cancer.

SUMMARY

The results of active surveillance, embodying conservative management with selective, delayed intervention for the subset who are reclassified as higher risk over time based on repeat biopsy, imaging, or biomarker results, have shown that this approach is safe in the intermediate to long term, with a 0.5-3% cancer-specific mortality at 10-15 years. Further refinement incorporating MRI and targeted biopsies is the subject of intensive research at the moment, and promises to improve the safety and precision of conservative management.

Current Management Strategy for Active Surveillance in Prostate Cancer

PURPOSE OF REVIEW

Active surveillance has been increasingly utilized as a strategy for the management of favorable-risk, localized prostate cancer. In this review, we describe contemporary management strategies of active surveillance, with a focus on traditional stratification schemes, new prognostic tools, and patient outcomes.

RECENT FINDINGS

Patient selection, follow-up strategy, and indication for delayed intervention for active surveillance remain centered around PSA, digital rectal exam, and biopsy findings. Novel tools which include imaging, biomarkers, and genetic assays have been investigated as potential prognostic adjuncts; however, their role in active surveillance remains institutionally dependent. Although 30-50% of patients on active surveillance ultimately undergo delayed treatment, the vast majority will remain free of metastasis with a low risk of dying from prostate cancer. The optimal method for patient selection into active surveillance is unknown; however, cancer-specific mortality rates remain excellent. New prognostication tools are promising, and long-term prospective, randomized data regarding their use in active surveillance will be beneficial.

New Strategies in Prostate Cancer: Prostate-Specific Membrane Antigen (PSMA) Ligands for Diagnosis and Therapy

Key issues for prostate cancer patients are the detection of recurrent disease and the treatment of metastasized cancer. Early detection is a major challenge for all conventional imaging modalities. Furthermore, therapy of patients with hormone-resistant tumor lesions presents a major clinical challenge. Because the prostate-specific membrane antigen (PSMA) is frequently overexpressed in prostate cancer, several PSMA-targeting molecules are under development to detect and treat metastatic castration-resistant prostate cancer (mCRPC). mCRPC represents a situation where cure is no longer achievable and novel therapeutic approaches for palliation and increase of survival are needed. In this article, we discuss the recent development for noninvasive detection of recurrent disease and therapy of mCRPC with corresponding PSMA-targeted radioligands.

Ablative therapy for people with localised prostate cancer: a systematic review and economic evaluation

BACKGROUND

For people with localised prostate cancer, active treatments are effective but have significant side effects. Minimally invasive treatments that destroy (or ablate) either the entire gland or the part of the prostate with cancer may be as effective and cause less side effects at an acceptable cost. Such therapies include cryotherapy, high-intensity focused ultrasound (HIFU) and brachytherapy, among others.

OBJECTIVES

This study aimed to determine the relative clinical effectiveness and cost-effectiveness of ablative therapies compared with radical prostatectomy (RP), external beam radiotherapy (EBRT) and active surveillance (AS) for primary treatment of localised prostate cancer, and compared with RP for salvage treatment of localised prostate cancer which has recurred after initial treatment with EBRT.

DATA SOURCES

MEDLINE (1946 to March week 3, 2013), MEDLINE In-Process & Other Non-Indexed Citations (29 March 2013), EMBASE (1974 to week 13, 2013), Bioscience Information Service (BIOSIS) (1956 to 1 April 2013), Science Citation Index (1970 to 1 April 2013), Cochrane Central Register of Controlled Trials (CENTRAL) (issue 3, 2013), Cochrane Database of Systematic Reviews (CDSR) (issue 3, 2013), Database of Abstracts of Reviews of Effects (DARE) (inception to March 2013) and Health Technology Assessment (HTA) (inception to March 2013) databases were searched. Costs were obtained from NHS sources.

REVIEW METHODS

Evidence was drawn from randomised controlled trials (RCTs) and non-RCTs, and from case series for the ablative procedures only, in people with localised prostate cancer. For primary therapy, the ablative therapies were cryotherapy, HIFU, brachytherapy and other ablative therapies. The comparators were AS, RP and EBRT. For salvage therapy, the ablative therapies were cryotherapy and HIFU. The comparator was RP. Outcomes were cancer related, adverse effects (functional and procedural) and quality of life. Two reviewers extracted data and carried out quality assessment. Meta-analysis used a Bayesian indirect mixed-treatment comparison. Data were incorporated into an individual simulation Markov model to estimate cost-effectiveness.

RESULTS

The searches identified 121 studies for inclusion in the review of patients undergoing primary treatment and nine studies for the review of salvage treatment. Cryotherapy [3995 patients; 14 case series, 1 RCT and 4 non-randomised comparative studies (NRCSs)], HIFU (4000 patients; 20 case series, 1 NRCS) and brachytherapy (26,129 patients; 2 RCTs, 38 NRCSs) studies provided limited data for meta-analyses. All studies were considered at high risk of bias. There was no robust evidence that mortality (4-year survival 93% for cryotherapy, 99% for HIFU, 91% for EBRT) or other cancer-specific outcomes differed between treatments. For functional and quality-of-life outcomes, the paucity of data prevented any definitive conclusions from being made, although data on incontinence rates and erectile dysfunction for all ablative procedures were generally numerically lower than for non-ablative procedures. The safety profiles were comparable with existing treatments. Studies reporting the use of focal cryotherapy suggested that incontinence rates may be better than for whole-gland treatment. Data on AS, salvage treatment and other ablative therapies were too limited. The cost-effectiveness analysis confirmed the uncertainty from the clinical review and that there is no technology which appears superior, on the basis of current evidence, in terms of average cost-effectiveness. The probabilistic sensitivity analyses suggest that a number of ablative techniques are worthy of further research.

LIMITATIONS

The main limitations were the quantity and quality of the data available on cancer-related outcomes and dysfunction.

CONCLUSIONS

The findings indicate that there is insufficient evidence to form any clear recommendations on the use of ablative therapies in order to influence current clinical practice. Research efforts in the use of ablative therapies in the management of prostate cancer should now be concentrated on the performance of RCTs and the generation of standardised outcomes.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002461.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Metastatic Prostate Cancer in Men Initially Treated with Active Surveillance

PURPOSE

Active surveillance is an approach to low and low intermediate risk prostate cancer that is designed to decrease overtreatment. Despite close monitoring a small subset of patients progress to metastatic disease. We analyzed the clinical and pathological correlates of surveillance in patients who eventually experienced metastasis.

MATERIALS AND METHODS

This was a single center, prospective cohort study. Eligible patients were treated with an expectant approach. The main outcome measure was metastasis-free survival. Predictive factors for metastasis were identified.

RESULTS

Metastasis developed in 30 of 980 patients, of whom 211 were classified at intermediate risk, including 14 who progressed to metastatic disease. Median followup was 6.3 years, median age was 70 years, median prostate specific antigen was 6.2 ng/ml and median time to metastasis was 8.9 years. Metastases developed in bone in 18 patients (60%) and in lymph nodes in 13 (43%). Prostate specific antigen doubling time less than 3 years (HR 3.7, 95% CI 1.4-9.4, p = 0.0006), Gleason score 7 (HR 3.0, 95% CI 1.2-7.3, p = 0.0018) and a total of 3 or more positive cores (HR 2.7, 95% CI 1.1-6.8, p = 0.0028) were independent predictors of metastasis. Although the intermediate risk group was at higher risk for metastasis, those with Gleason score 6 and prostate specific antigen greater than 10 ng/ml were not at increased risk for metastasis. Metastasis developed in only 2 patients with Gleason score 6 and neither had surgical pathology grading.

CONCLUSION

Active surveillance appears safe in patients at low risk and in select patients at intermediate risk, particularly those with Gleason score 6 and prostate specific antigen greater than 10 ng/ml. Patients with elements of Gleason pattern 4 on diagnostic biopsy are at increased risk for eventual metastasis when treated with an initial conservative approach.

Factors Influencing Selection of Active Surveillance for Localized Prostate Cancer

OBJECTIVE

To determine how well demographic and clinical factors predict the initiation of Active Surveillance (AS).

METHODS

AS has been suggested as a way to reduce overtreatment of men who have prostate cancer; however, factors associated with the decision to choose AS are poorly quantified. Using the Michigan Urological Surgery Improvement Collaborative registry, we identified 2977 men with prostate cancer who made treatment decisions from January 1, 2012, through December 31, 2013. We used chi-square and Wilcoxon tests to examine the association between factors and initiation of AS. Logistic regression models were fit for D'Amico risk categories. Measures of model discrimination and calibration were estimated, including area under the curve (AUC) and Brier score (BS).

RESULTS

Patient age, Gleason score, clinical T-stage, urology practice, and tumor volume (greatest percent of a core involved with cancer and proportion of positive cores) were associated with the decision to choose AS in the intermediate-risk cohort (AUC = 0.875, BS = 0.07) and the complete cohort (AUC = 0.89, BS = 0.10). Patient age, urology practice, and tumor volume were significant in the low-risk cohort (AUC = 0.71, BS = 0.22). The addition of urology practice increased AUC in the low-risk cohort from 0.71 to 0.76 and reduced BS from 0.22 to 0.21.

CONCLUSION

The urology practice at which a patient is seen is an important predictor for whether patients will initiate AS. Predictions were least accurate for low-risk patients, suggesting that factors such as patient preference play a role in treatment decisions.

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

OBJECTIVES

To determine the frequency of disease reclassification and to identify clinicopathological variables associated with it in patients with favourable-risk prostate cancer undergoing active surveillance (AS).

PATIENTS AND METHODS

We assessed 191 men, selected by what may be the most stringent criteria used in AS studies yet conducted, who were enrolled in a prospective cohort AS trial. Clinicopathological characteristics were analysed in a multivariate Cox proportional hazards regression model. Key features were an extended biopsy with a single core positive for Gleason score (GS) 3 + 3 (<3 mm) or 3 + 4 (<2 mm) and a prostate-specific antigen (PSA) level <4 ng/mL (adjusted for prostate volume). Biopsies were repeated every 1-2 years and clinical evaluations every 6 months. Disease was reclassified when PSA level increased by 30% from baseline, or when biopsy tumour length increased beyond the enrolment criteria, more than one positive core was detected or any grade increased to a dominant 4 pattern or any 5 pattern.

RESULTS

Disease was reclassified in 32 patients (16.8%) including upgrading to GS 4 + 3 in five patients (2.6%). The median (interquartile range) follow-up time among survivors was 3 (1.9-4.6) years. Overall, 13 of the 32 (40.6%) had incremental increases in GS. Tumour length (hazard ratio 2.95, 95% confidence interval [CI] 1.34-6.46; P = 0.007) and older age (hazard ratio 1.05, 95% CI 1.00-1.09; P = 0.05) were identified as significant and marginally significant predictors of disease reclassification, respectively. Disease remained stable in 83.2% of patients.

CONCLUSION

The need persists for improvements in risk stratification and predictive indicators of cancer progression.

Active surveillance and focal therapy for low-intermediate risk prostate cancer

Low risk and many cases of low-intermediate risk prostate cancer, are indolent, have little or no metastatic potential, and are not life threatening. Major advances have been made in understanding who these patients are, and in encouraging the use of conservative management in such individuals. Conservative management incorporates the early identification of those 'low risk' patients who harbor higher risk disease, and benefit from definitive therapy. Based on the current algorithm of PSA followed by systematic biopsy, this represents about 30% of newly diagnosed low risk patients. A further small proportion of patients with low risk disease demonstrate biological progression to higher grade disease. Men with lower risk disease can defer treatment, usually for life. Men with higher risk disease that can be localized to a relatively small volume of the prostate may be candidates for focal, prostate sparing therapy. The results of active surveillance, embodying conservative management with selective delayed intervention for the subset who are re-classified as higher risk over time based on repeat biopsy, imaging, or biomarker results, have shown that this approach is safe in the intermediate to long term, with a 1-5% cancer specific mortality at 15 years. Further refinement of the surveillance approach is ongoing, incorporating MRI, targeted biopsies, and molecular biomarkers.

Long-term follow-up of a large active surveillance cohort of patients with prostate cancer

PURPOSE

Active surveillance is increasingly accepted as a treatment option for favorable-risk prostate cancer. Long-term follow-up has been lacking. In this study, we report the long-term outcome of a large active surveillance protocol in men with favorable-risk prostate cancer.

PATIENTS AND METHODS

In a prospective single-arm cohort study carried out at a single academic health sciences center, 993 men with favorable- or intermediate-risk prostate cancer were managed with an initial expectant approach. Intervention was offered for a prostate-specific antigen (PSA) doubling time of less than 3 years, Gleason score progression, or unequivocal clinical progression. Main outcome measures were overall and disease-specific survival, rate of treatment, and PSA failure rate in the treated patients.

RESULTS

Among the 819 survivors, the median follow-up time from the first biopsy is 6.4 years (range, 0.2 to 19.8 years). One hundred forty-nine (15%) of 993 patients died, and 844 patients are alive (censored rate, 85.0%). There were 15 deaths (1.5%) from prostate cancer. The 10- and 15-year actuarial cause-specific survival rates were 98.1% and 94.3%, respectively. An additional 13 patients (1.3%) developed metastatic disease and are alive with confirmed metastases (n = 9) or have died of other causes (n = 4). At 5, 10, and 15 years, 75.7%, 63.5%, and 55.0% of patients remained untreated and on surveillance. The cumulative hazard ratio for nonprostate-to-prostate cancer mortality was 9.2:1.

CONCLUSION

Active surveillance for favorable-risk prostate cancer is feasible and seems safe in the 15-year time frame. In our cohort, 2.8% of patients have developed metastatic disease, and 1.5% have died of prostate cancer. This mortality rate is consistent with expected mortality in favorable-risk patients managed with initial definitive intervention.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

CONTEXT

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

OBJECTIVE

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

PATIENT SUMMARY

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

The critical role of the pathologist in determining eligibility for active surveillance as a management option in patients with prostate cancer: consensus statement with recommendations supported by the College of American Pathologists, International Society of Urological Pathology, Association of Directors of Anatomic and Surgical Pathology, the New Zealand Society of Pathologists, and the Prostate Cancer Foundation

CONTEXT

Prostate cancer remains a significant public health problem. Recent publications of randomized trials and the US Preventive Services Task Force recommendations have drawn attention to overtreatment of localized, low-risk prostate cancer. Active surveillance, in which patients undergo regular visits with serum prostate-specific antigen tests and repeat prostate biopsies, rather than aggressive treatment with curative intent, may address overtreatment of low-risk prostate cancer. It is apparent that a greater awareness of the critical role of pathologists in determining eligibility for active surveillance is needed.

OBJECTIVES

To review the state of current knowledge about the role of active surveillance in the management of prostate cancer and to provide a multidisciplinary report focusing on pathologic parameters important to the successful identification of patients likely to succeed with active surveillance, to determine the role of molecular tests in increasing the safety of active surveillance, and to provide future directions.

DESIGN

Systematic review of literature on active surveillance for low-risk prostate cancer, pathologic parameters important for appropriate stratification, and issues regarding interobserver reproducibility. Expert panels were created to delineate the fundamental questions confronting the clinical and pathologic aspects of management of men on active surveillance.

RESULTS

Expert panelists identified pathologic parameters important for management and the related diagnostic and reporting issues. Consensus recommendations were generated where appropriate.

CONCLUSIONS

Active surveillance is an important management option for men with low-risk prostate cancer. Vital to this process is the critical role pathologic parameters have in identifying appropriate candidates for active surveillance. These findings need to be reproducible and consistently reported by surgical pathologists with accurate pathology reporting.

Extended followup and risk factors for disease reclassification in a large active surveillance cohort for localized prostate cancer

PURPOSE

Active surveillance to manage prostate cancer provides an alternative to immediate treatment in men with low risk prostate cancer. We report updated outcomes from a long-standing active surveillance cohort and factors associated with reclassification.

MATERIALS AND METHODS

We retrospectively reviewed data on all men enrolled in the active surveillance cohort at our institution with at least 6 months of followup between 1990 and 2013. Surveillance consisted of quarterly prostate specific antigen testing, repeat imaging with transrectal ultrasound at provider discretion and periodic repeat prostate biopsies. Factors associated with repeat biopsy reclassification and local treatment were determined by multivariate Cox proportional hazards regression. We also analyzed the association of prostate specific antigen density and outcomes stratified by prostate size.

RESULTS

A total of 810 men who consented to participate in the research cohort were followed on active surveillance for a median of 60 months. Of these men 556 (69%) met strict criteria for active surveillance. Five-year overall survival was 98%, treatment-free survival was 60% and biopsy reclassification-free survival was 40%. There were no prostate cancer related deaths. On multivariate analysis prostate specific antigen density was positively associated with the risk of biopsy reclassification and treatment while the number of biopsies and time between biopsies were inversely associated with the 2 outcomes (each p <0.01). When stratified by prostate volume, prostate specific antigen density remained significantly associated with biopsy reclassification for all strata but prostate specific antigen density was only significantly associated with treatment in men with a smaller prostate.

CONCLUSIONS

Significant prostate cancer related morbidity and mortality remained rare at intermediate followup. Prostate specific antigen density was independently associated with biopsy reclassification and treatment while on active surveillance.

Management of low risk prostate cancer-active surveillance and focal therapy

Low-risk prostate cancer, defined as Gleason Score 6 or less with PSA <10 ng/ml, is diagnosed in about half of men undergoing screening. Approximately 30% of men diagnosed with low-risk disease harbour high-grade cancer that is unrepresented on the biopsy. Moreover, a small percentage of low-grade cancers have molecular alterations that result in progression to aggressive disease. Favourable-risk prostate cancer should be managed with close follow up. Active surveillance is appropriate for most patients with low-risk disease, and radical treatment should be reserved for cases in which higher-risk disease is identified. In turn, focal therapy aims to preserve tissue and function in men who have been diagnosed with localized disease, and should be offered to men with higher risk disease at baseline, as an alternative to whole-gland radiation or surgery, or when the patient transitions from low-risk to higher-risk disease. The two strategies should be viewed as complementary elements of care that can be applied in a risk-stratified manner. In this Review, we discuss the rationale and current status of active surveillance-which constitutes a standard of care in most evidence-based guidelines-and comment on whether and when focal therapy should complement it in those men wishing to continue a tissue-preserving strategy.

Imaging and Markers as Novel Diagnostic Tools in Detecting Insignificant Prostate Cancer: A Critical Overview

Recent therapeutic advances for managing low-risk prostate cancer include the active surveillance and focal treatment. However, locating a tumor and detecting its volume by adequate sampling is still problematic. Development of predictive biomarkers guiding individual therapeutic choices remains an ongoing challenge. At the same time, prostate cancer magnetic resonance imaging is gaining increasing importance for prostate diagnostics. The high morphological resolution of T2-weighted imaging and functional MRI methods may increase the specificity and sensitivity of diagnostics. Also, recent studies founded an ability of novel biomarkers to identify clinically insignificant prostate cancer, risk of progression, and association with poor differentiation and, therefore, with clinical significance. Probably, the above mentioned methods would improve tumor characterization in terms of its volume, aggressiveness, and focality. In this review, we attempted to evaluate the applications of novel imaging techniques and biomarkers in assessing the significance of the prostate cancer.

Active surveillance for prostate cancer: overview and update

Low-risk prostate cancer: How I would treat it? Overtreatment of many conditions diagnosed by screening has become increasingly recognized as a contemporary malady associated with modern medicine's efforts at earlier detection. The diagnosis of low-grade prostate cancer clearly qualifies as an example of potential overdiagnosis and overtreatment. Active surveillance for low-risk prostate cancer is an attempt to reduce the overtreatment of the disease. The approach involves initial expectant management rather than immediate therapy. Curative treatment is deferred while the patient is monitored and offered for evidence of risk reclassification to a more aggressive form of the disease. The basis for this approach is substantial evidence confirming the long natural history of most prostate cancers. The objective is to balance the risks of overtreatment and associated adverse quality of life effects, against the risk of progression of disease and a missed opportunity for curative therapy. Low-risk prostate cancer is more accurately viewed as one of several risk factors for the patient harboring higher-grade disease, rather than a life-threatening condition. This approach is similar to that taken historically for so-called precancerous conditions, such as PIN or ASAP, where patients were managed with close follow-up but without radical intervention unless clear evidence of more aggressive disease is identified. Active surveillance is increasingly viewed as the management of choice for patients with very low-risk (low-grade, low-volume prostate cancer) and low-risk (low-grade but higher volume) disease.

Active surveillance for favorable-risk prostate cancer: background, patient selection, triggers for intervention, and outcomes

With the advent of increasingly sensitive and widely used diagnostic testing, cancer overdiagnosis in particular has emerged as a problem in multiple organ sites. This has the greatest ramifications in the case of prostate cancer because of the very high incidence of latent prostate cancer in aging men, the availability of the prostate-specific antigen (PSA) test, and the long-term effects of definitive therapy. The condition of most men with favorable-risk prostate cancer is far removed from the consequences of a rampaging, aggressive disease. Most of these men are not destined to die of their disease, even in the absence of treatment. Unfortunately, most of these patients are treated radically and are exposed to the risk of significant side effects. Therefore, a selective approach to treatment is appealing. The concept is to identify the subset that harbor more aggressive disease early enough that curative therapy is still a possibility, thereby allowing the others to enjoy improved quality of life, free from the side effects of treatment. This review article summarizes the evidence supporting active surveillance, and the current approach to this management strategy, including the roles of serial biopsy, PSA kinetics, and MR imaging.

Active surveillance for low-risk prostate cancer

Active surveillance for localized prostate cancer entails initial expectant management rather than immediate therapy, with "curative-intent" treatment deferred until there is evidence that the patient is at increased risk for disease progression. This is a response to the clearly documented risks of over diagnosis and overtreatment of low-risk prostate cancer, which in most cases poses little or no threat to the patient. It is based upon the prolonged natural history of prostate cancer and is an attempt to balance the risks and side effects of overtreatment against the possibility of disease progression and a lost opportunity for cure. Low-risk prostate cancer is more accurately viewed as one of multiple risk factors for the presence of higher grade prostate cancer. Like atypical small acinar proliferation, (ASAP), it may be managed with close follow up but without radical intervention, unless there is clear evidence of more aggressive disease.

Active surveillance in prostate cancer: patient selection and triggers for intervention

PURPOSE OF REVIEW

The long-term safety and effectiveness of active surveillance depends on our ability to select appropriate patients and trigger delayed treatment in those who need it, whereas avoiding intervention in those who do not. In this review, we will consider how recent advances have influenced patient selection for active surveillance and review the range of different intervention triggers that have been proposed.

RECENT FINDINGS

Several large surveillance cohort studies have been reported recently showing excellent medium-term outcomes in well selected patients, with approximately a third of patients going on to have deferred treatment. Debate continues on the most appropriate eligibility criteria for active surveillance and what triggers for intervention should be used. There is growing interest in the role of transperineal template biopsies and multiparametric MRI, both for patient selection and in identifying triggers for intervention.

SUMMARY

Active surveillance is a well tolerated treatment option in well selected groups of patients. There is no 'one size fits all' set of criteria for patient selection or triggers for intervention but decisions can be guided by information from histology, prostate-specific antigen kinetics and imaging.

Robotic transperineal prostate biopsy: pilot clinical study

OBJECTIVE

To develope a robot (BioXbot) that performs mapping transperineal prostate biopsy (PB) with two perineal skin punctures under ultrasound guidance. Our pilot study's clinical endpoints were complications and its technical endpoints were the duration for each phase.

METHODS

This institution review board-approved prospective clinical trial included patients with indications for PB. Two urologists performed these PBs. In the lithotomy position and under general anesthesia, the transrectal biplane ultrasound probe acquired transverse images of the prostate gland. The urologist defined its boundaries and planned the biopsy. It guided the PB in 3 axes, passing through a single perineal skin puncture for each prostate side. After each biopsy, it automatically moved to the next position. The steps were repeated on the contralateral side.

RESULTS

Our 20 patients had a mean prostate-specific antigen of 8.4 ± 4.9 ng/mL. Two patients had 2 previous biopsies, whereas the rest had one. The mean number of biopsies taken was 28.5 ± 6.2 in a mean total procedure time of 32.5 ± 3.2 minutes. We detected 3 patients with prostate cancer with Gleason score 3 + 3. Two patients required brief bladder catheterization after their biopsy. Their prostate volumes were >50 mL and the number of biopsies taken was >30 cores. There was no mechanical failure, sepsis, bleeding per-rectal, or perineal hematoma.

CONCLUSION

This pilot study demonstrated BioXbot's safety and feasibility as a biopsy platform. It can potentially be used for image-guided PB and focal therapy.