Reasons for Discontinuing Active Surveillance: Assessment of 21 Centres in 12 Countries in the Movember GAP3 Consortium

Has Active Surveillance for Prostate Cancer Become Safer? Lessons Learned from a Global Clinical Registry

BACKGROUND AND OBJECTIVE

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men around the world with low-risk prostate cancer (or in selected cases intermediate-risk disease). Here, we report on the safety and acceptability of AS, and treatment outcomes for low- and intermediate-risk tumours over time in 14 623 men with follow-up of over 6 yr.

METHODS

Clinical data from 26 999 men on AS from 25 cohorts in 15 countries have been collected in an international database from 2000 onwards.

KEY FINDINGS AND LIMITATIONS

Across our predefined four time periods of 4 yr each (covering the period 2000-2016), there was no significant change in overall survival (OS). However, metastasis-free survival (MFS) rates have improved since the second period and were excellent (>99%). Treatment-free survival rates for earlier periods showed a slightly more rapid shift to radical treatment. Over time, there was a constant proportion of 5% of men for whom anxiety was registered as the reason for treatment alteration. There was, however, also a subset of 10-15% in whom treatment was changed, for which no apparent reason was available. In a subset of men (10-15%), tumour progression was the trigger for treatment. In men who opted for radical treatment, surgery was the most common treatment modality. In those men who underwent radical treatment, 90% were free from biochemical recurrence at 5 yr after treatment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our study confirms that AS was a safe management option over the full duration in this large multicentre cohort with long-term follow-up, given the 84.1% OS and 99.4% MFS at 10 yr. The probability of treatment at 10 yr was 20% in men with initial low-risk tumours and 31% in men with intermediate-risk tumours. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

PATIENT SUMMARY

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men with prostate cancer around the world. In this report, we show the long-term safety of following AS for men with low- and intermediate-risk prostate cancer. Our study confirms AS as a safe management option for low- and intermediate-risk prostate cancer. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

Irreversible Electroporation for the Focal Treatment of Prostate Cancer: A Systematic Review

PURPOSE

Irreversible electroporation (IRE) is a promising alternative treatment for low-intermediate-risk localized prostate cancer. In this systematic review we aim to evaluate the safety profile and functional and oncological outcomes of this new technique.

MATERIALS AND METHODS

A systematic review of the literature was performed on PubMed, EMBASE, and Scopus up to 24 August 2023. Nineteen studies were analyzed, including 12 prospective studies and 7 retrospective studies. A total of 1,452 patients underwent IRE as the sole primary treatment modality.

RESULTS

The in-field clinically significant prostate cancer rate was reported between 0%-15.6% in the repeat biopsy. The retreatment rate was reported from 8% to 36.6%. The 3 years failure-free survival was presented between 90%-96.8%. The post-operative pad-free rate ranged between 96.7%-100%. Greater heterogeneity exists considering the change in erectile function. The most common reported complications were urinary tract infection and hematuria. Major complications were rare.

CONCLUSIONS

These results underline that IRE achieves favorable oncological control with an excellent safety profile, in the meantime preserving patients' urinary and erectile function.

Do health professionals know about overdiagnosis in screening, and how are they dealing with it? A mixed-methods systematic scoping review

INTRODUCTION

Medical screening is a major driver of overdiagnosis, which should be considered when making an informed screening decision. Health professionals (HPs) often initiate screening and are therefore responsible for informing eligible screening participants about the benefits and harms of screening. However, little is known about HPs' knowledge of overdiagnosis and whether they are prepared to inform screening candidates about this risk and enable people to make an informed screening decision.

METHODS

This is a systematic review of studies examining HPs' knowledge and perception of overdiagnosis, whether it affects their position on offering screening, and their willingness to inform screening candidates about overdiagnosis. We conducted systematic searches in MEDLINE, Embase, Web of Science, Scopus, CINAHL, and PsycArticles without language restrictions. Two authors analysed the qualitative and quantitative data separately. Confidence in the findings of the qualitative data was assessed using the GRADE-CERQual approach.

RESULTS

We included 23 publications after screening 9786 records. No studies directly examined HPs' knowledge of overdiagnosis. HPs' perceptions of overdiagnosis varied widely, from considering it a significant harm to seeing it as negligible. This seems linked to their overall beliefs about the benefits and harms of screening and to their position on offering screening, which varies from discouraging to actively promoting it. HPs also hold diverging approaches to informing screening candidates about overdiagnosis, from providing detailed explanations to limited or no information.

CONCLUSION

There is a lack of research on HPs' knowledge of overdiagnosis, however, HPs who do know about overdiagnosis attribute substantially different levels of harm to it. This seems intertwined with their overall beliefs about the benefits of screening, their position towards offering screening, and their willingness to inform screening candidates about overdiagnosis. This has important implications for the public's right to evidence-based information and compromises an individual's right to make an informed screening decision.

The 5-year results of the Stratified Cancer Active Surveillance programme for men with prostate cancer

OBJECTIVES

To report 5-year outcomes from the STRATified CANcer Surveillance (STRATCANS) programme based on progression risks using National Institute for Health and Clinical Excellence (NICE) Cambridge Prognostic Group (CPG) at diagnosis, prostate specific antigen density and magnetic resonance imaging (MRI) visibility.

PATIENTS AND METHODS

Men with CPG1 and CPG2 disease selecting active surveillance (AS) were included into STRATCANS and allocated to one of three increasing follow-up intensities. Outcome measures were: (i) treatment for CPG≥3 progression (main outcome), (ii) any treatment, (iii) conversion to watchful waiting (WW), (iv) patient self-attrition, and (v) mortality.

RESULTS

A total of 297 men (median age 66.0 years) were reviewed. The median (interquartile range, mean) follow-up for men still on AS was 4.9 (2.7-7.6, 5.3) years. In the cohort, 38.0% were CPG2 and 25.0% Grade Group (GG) 2 at AS entry. Overall, 214/297 (72.1%) remained treatment free: 158 (53.1%) were still on AS, 17 (5.7%) died of other causes, and 39 (13.1%) progressed to WW/discharge. Only 10 (3.4%) left AS from anxiety. There were no cancer deaths or metastatic events. In all, 80 men (26.9%) converted to treatment due to biopsy/MRI progression but only 35 (11.7%) of these reached CPG≥3 disease. Treatment for CPG≥3 occurred in 7.6% of CPG1 and 18.5% of CPG2 disease and 9.9% of GG1 and 17.5% of GG2 disease. By STRATCANS tier, treatment for CPG≥3 disease was 4.7% in STRATCANS 1, 12.9% in STRATCANS 2, and 27.4% in STRATCANS 3 (P < 0.001). STRATCANS had an area under the curve (AUC) of 0.74 for predicting CPG≥3 progression out-performing stratification by GG (AUC 0.64), CPG (0.69) and Likert score (0.51) alone or a combination of MRI visibility and GG (0.64). Longitudinal data have allowed further refinement of the STRATCANS schedule.

CONCLUSIONS

The STRATCANS 5-year outcomes demonstrate that a simple risk stratified surveillance using a prognostically meaningful endpoint is safe, durable, has low treatment rates, high patient compliance and appropriately tailors monitoring based on risks of progression. A website and implementation toolkit are now available.

Unsupervised self-organising map classification of Raman spectra from prostate cell lines uncovers substratified prostate cancer disease states

Prostate cancer is a disease which poses an interesting clinical question: Should it be treated? Only a small subset of prostate cancers are aggressive and require removal and treatment to prevent metastatic spread. However, conventional diagnostics remain challenged to risk-stratify such patients; hence, new methods of approach to biomolecularly sub-classify the disease are needed. Here we use an unsupervised self-organising map approach to analyse live-cell Raman spectroscopy data obtained from prostate cell-lines; our aim is to exemplify this method to sub-stratify, at the single-cell-level, the cancer disease state using high-dimensional datasets with minimal preprocessing. The results demonstrate a new sub-clustering of the prostate cancer cell-line into two groups-protein-rich and lipid-rich sub-cellular components-which we believe to be mechanistically linked. This finding shows the potential for unsupervised machine learning to discover distinct disease-state features for more accurate characterisation of highly heterogeneous prostate cancer. Applications may lead to more targeted diagnoses, prognoses and clinical treatment decisions via molecularly-informed stratification that would benefit patients. A method that could discover distinct disease-state features that are mechanistically linked could also assist in the development of more effective broad-spectrum treatments that simultaneously target linked disease-state processes.

Time trends for the use of active surveillance and deferred treatment for localised prostate cancer in Sweden: a nationwide study

OBJECTIVE

Active surveillance (AS) is recommended for low-risk and some favourable intermediate-risk prostate cancers, but criteria for AS and deferred treatment have changed over time. We assessed time trends for the use of AS and deferred treatment.

MATERIAL AND METHODS

Nationwide Swedish register study of 76,191 men diagnosed with low- or intermediate-risk localised prostate cancer from 2008 to 2020. This study presents the proportion of men starting on AS, their clinical characteristics and proportion having deferred treatment. Cox regression was used to calculate hazard ratios for deferred treatment. Subgroup analyses were performed for men < 60 years with Charlson Comorbidity Index 0.

RESULTS

Overall use of AS increased from 2008-2010 to 2017-2020: any low-risk: 40% to 81%, very low-risk disease: 57% to 91%, other low-risk: 37% to 77% and intermediate-risk: 16% to 20%. The relative increase in the use of AS in men < 60 years with Charlson Comorbidity Index 0 was similar to, or greater than, the increase overall. A total of 28,211 men started on AS. The crude proportions of men receiving deferred treatment were relatively stable over time; 2017-2020: very low-risk disease 8%, other low-risk 16% and intermediate-risk 23%. After adjustment for clinical characteristics, deferred treatment within 2 years decreased over time for very low-risk, was stable for other low-risk and increased for intermediate-risk cancer.

CONCLUSIONS

The use of AS greatly increased over time, not least amongst younger healthy men, whereas the use of deferred treatment was relatively stable. AS has been increasingly accepted as a safe approach for localised, favourable-risk prostate cancer.

Is MRI ready to replace biopsy during active surveillance?

Active surveillance (AS) is a conservative management option recommended for patients diagnosed with low-risk prostate cancer (PCa) and selected cases with intermediate-risk PCa. The adoption of prostate MRI in the primary diagnostic setting has sparked interest in its application during AS. This review aims to examine the role and performance of multiparametric MRI (mpMRI) across the entire AS pathway, from initial stratification to follow-up, also relative to the utilization of the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) criteria. Given the high negative predictive value of mpMRI in detecting clinically significant PCa (csPCa), robust evidence supports its use in patient selection and risk stratification at the time of diagnosis or confirmatory biopsy. However, conflicting results have been observed when using MRI in evaluating disease progression during follow-up. Key areas requiring clarification include addressing the clinical significance of MRI-negative csPCa, optimizing MRI quality, determining the role of biparametric MRI (bpMRI) or mpMRI protocols, and integrating artificial intelligence (AI) for improved performance. CLINICAL RELEVANCE STATEMENT: MRI plays an essential role in the selection, stratification, and follow up of patients in active surveillance (AS) for prostate cancer. However, owing to existing limitations, it cannot fully replace biopsies in the context of AS. KEY POINTS: Multiparametric MRI (mpMRI) has become a crucial tool in active surveillance (AS) for prostate cancer (PCa). Conflicting results have been observed regarding multiparametric MRI efficacy in assessing disease progression. Standardizing MRI-guided protocols will be critical in addressing current limitations in active surveillance for prostate cancer.

Projected Outcomes of Reduced-Biopsy Management of Grade Group 1 Prostate Cancer: Implications for Relabeling

BACKGROUND

Implications of relabeling grade group (GG) 1 prostate cancer as non-cancer will depend on the recommended active surveillance (AS) strategy. Whether relabeling should prompt de-intensifying, PSA-based active monitoring approaches is unclear. We investigated outcomes of biopsy-based AS strategies vs PSA-based active monitoring for GG1 diagnoses under different patient adherence rates.

METHODS

We analyzed longitudinal PSA levels and time to GG ≥ 2 reclassification among 850 patients diagnosed with GG1 disease from the Canary Prostate Active Surveillance Study (2008-2013). We then simulated 20,000 patients over 12 years, comparing GG ≥ 2 detection under biennial biopsy against three PSA-based strategies:(1) PSA: biopsy for PSA change ≥20%/year, (2) PSA+MRI: MRI for PSA change ≥20%/year and biopsy for PI-RADS ≥3, and (3) Predicted risk: biopsy for predicted upgrading risk ≥10%.

RESULTS

Under biennial biopsies and 20% dropout to active treatment, 17% of patients had a > 2-year delay in GG ≥ 2 detection. The PSA strategy reduced biopsies by 39% but delayed detection in 32% of patients. The PSA+MRI strategy cut biopsies by 52%, with a 34% delay. The predicted risk strategy reduced biopsies by 31%, with only an 8% delay. These findings are robust to biopsy sensitivity and confirmatory biopsy.

CONCLUSIONS

PSA-based active monitoring could substantially reduce biopsy frequency; however, a precision strategy based on an individual upgrading risk is most likely to minimize delays in disease progression detection. This strategy may be preferred if AS is deintensified under relabeling, provided patient adherence remains unaffected.

Surveillance after Focal Therapy - a Comprehensive Review

BACKGROUND

to date, no standardized, evidence-based follow-up schemes exist for the monitoring of patients who underwent focal therapy (FT) and expert centers rely mainly on their own experience and/or institutional protocols. We aimed to perform a comprehensive review of the most advantageous follow-up strategies and their rationale after FT for prostate cancer (PCa).

METHODS

a narrative review of the literature was conducted to investigate different follow-up protocols of FT for PCa. Outcomes of interest were post-ablation oncological and functional outcomes and complications.

RESULTS

Oncological success after FT was generally defined as the biopsy-confirmed absence of clinically significant PCa in the treated zone. De novo PCa in the untreated area usually reflects an inaccurate patient selection and should be treated as primary PCa. During follow-up, oncological outcomes should be evaluated with periodic PSA, multiparametric MRI and prostate biopsy. The use of PSA derivatives and new biomarkers is still controversial and therefore not recommended. The first MRI after FT should be performed between 6-12 months to avoid ablation-related artifacts and diagnostic delay in case of FT failure. Other imaging modalities, such as PSMA PET/CT scan, are promising but still need to be validated in the post-FT setting. A 12-month "for-protocol" prostate biopsy, including targeted and systematic biopsy, was generally considered the preferred biopsy method to rule out tumor persistence/recurrence. Subsequent mpMRIs and biopsies should follow a risk-adapted approach depending on the clinical scenario. Functional outcomes should be periodically assessed using validated questionnaires within the first year, when typically recover to a new baseline. Complications, despite uncommon, should be strictly monitored mainly in the first month.

CONCLUSIONS

FT follow-up is a multifaceted process involving clinical, radiological, and histological assessment. Studies evaluating the impact of different follow-up strategies and ideal timings are needed to produce standardized protocols following FT.

Biparametric MRI in prostate cancer during active surveillance: is it safe?

Active surveillance (AS) is the preferred option for patients presenting with low-intermediate-risk prostate cancer. MRI now plays a crucial role for baseline assessment and ongoing monitoring of AS. The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) recommendations aid radiological assessment of progression; however, current guidelines do not advise on MRI protocols nor on frequency. Biparametric (bp) imaging without contrast administration offers advantages such as reduced costs and increased throughput, with similar outcomes to multiparametric (mp) MRI shown in the biopsy naïve setting. In AS follow-up, the paradigm shifts from MRI lesion detection to assessment of progression, and patients have the further safety net of continuing clinical surveillance. As such, bpMRI may be appropriate in clinically stable patients on routine AS follow-up pathways; however, there is currently limited published evidence for this approach. It should be noted that mpMRI may be mandated in certain patients and potentially offers additional advantages, including improving image quality, new lesion detection, and staging accuracy. Recently developed AI solutions have enabled higher quality and faster scanning protocols, which may help mitigate against disadvantages of bpMRI. In this article, we explore the current role of MRI in AS and address the need for contrast-enhanced sequences. CLINICAL RELEVANCE STATEMENT: Active surveillance is the preferred plan for patients with lower-risk prostate cancer, and MRI plays a crucial role in patient selection and monitoring; however, current guidelines do not currently recommend how or when to perform MRI in follow-up. KEY POINTS: Noncontrast biparametric MRI has reduced costs and increased throughput and may be appropriate for monitoring stable patients. Multiparametric MRI may be mandated in certain patients, and contrast potentially offers additional advantages. AI solutions enable higher quality, faster scanning protocols, and could mitigate the disadvantages of biparametric imaging.

From Screening to Mortality Reduction: An Overview of Empirical Data on the Patient Journey in European Randomized Study of Screening for Prostate Cancer Rotterdam After 21 Years of Follow-up and a Reflection on Quality of Life

BACKGROUND

Previous research quantified the effect of prostate-specific antigen (PSA)-based prostate cancer (PCa) screening on quality-adjusted life years using 11-yr follow-up data from the European Randomized Study of Screening for Prostate Cancer (ERSPC) extrapolated by the Microsimulation Screening Analysis (MISCAN). ERSPC data now matured to 21 yr of follow-up.

OBJECTIVE

To provide an overview of the effect of PSA-based screening on tumour characteristics and PCa treatment using long-term, detailed, empirical ERSPC data.

DESIGN, SETTING, AND PARTICIPANTS

Men were included from the ERSPC Rotterdam who were randomised to a PSA-based screening (S) or control (C) arm.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

We assessed the effects of PSA-based screening on the number of PCa diagnoses, tumour characteristics, treatments, and cumulative incidence of disease progression. We also evaluated the changes in tumour characteristics and treatments over time for both study arms.

RESULTS AND LIMITATIONS

Among PCa patients in the S-arm, fewer patients were diagnosed with advanced tumour stages (T3/T4: 12% vs 23%; relative risk [RR] = 0.50; 95% confidence interval [CI] 0.44-0.57), less disease progression was observed, and less secondary treatment (30% vs 48%; RR = 0.61; 95% CI 0.57-0.66; p < 0.001) and less palliative treatment were needed (21% vs 55%; RR = 0.38; 95% CI 0.35-0.42) than among those in the C-arm. This was at the cost of overdiagnosis and increased local treatments (eg, radical prostatectomy: 32% vs 14%; RR = 2.18; 95% CI 1.92-2.48). Over time, the number of local treatments decreased, whereas expectant management strategies increased. The RRs of treatments were slightly different from those of the MISCAN.

CONCLUSIONS

After 21 yr of follow-up, empirical data of the ERSPC showed that PSA-based screening reduces advanced PCa stages, disease progression, and extensive treatments at the cost of more overdiagnosis and probably more overtreatment. Our data showed reduced local treatments and increased expectant management strategies over time.

PATIENT SUMMARY

Prostate-specific antigen-based screening reduces the number of invasive prostate cancer treatments needed, however, at the cost of more overdiagnosis and probably more overtreatment. Limiting these costs remains crucial to benefit optimally from prostate cancer screening.

[68Ga]Ga‑PSMA‑617 PET-based radiomics model to identify candidates for active surveillance amongst patients with GGG 1-2 prostate cancer at biopsy

PURPOSE

To develop a radiomics-based model using [68Ga]Ga-PSMA PET/CT to predict postoperative adverse pathology (AP) in patients with biopsy Gleason Grade Group (GGG) 1-2 prostate cancer (PCa), assisting in the selection of patients for active surveillance (AS).

METHODS

A total of 75 men with biopsy GGG 1-2 PCa who underwent radical prostatectomy (RP) were enrolled. The patients were randomly divided into a training group (70%) and a testing group (30%). Radiomics features of entire prostate were extracted from the [68Ga]Ga-PSMA PET scans and selected using the minimum redundancy maximum relevance algorithm and the least absolute shrinkage and selection operator regression model. Logistic regression analyses were conducted to construct the prediction models. Receiver operating characteristic (ROC) curve, decision curve analysis (DCA), and calibration curve were employed to evaluate the diagnostic value, clinical utility, and predictive accuracy of the models, respectively.

RESULTS

Among the 75 patients, 30 had AP confirmed by RP. The clinical model showed an area under the curve (AUC) of 0.821 (0.695-0.947) in the training set and 0.795 (0.603-0.987) in the testing set. The radiomics model achieved AUC values of 0.830 (0.720-0.941) in the training set and 0.829 (0.624-1.000) in the testing set. The combined model, which incorporated the Radiomics score (Radscore) and free prostate-specific antigen (FPSA)/total prostate-specific antigen (TPSA), demonstrated higher diagnostic efficacy than both the clinical and radiomics models, with AUC values of 0.875 (0.780-0.970) in the training set and 0.872 (0.678-1.000) in the testing set. DCA showed that the net benefits of the combined model and radiomics model exceeded those of the clinical model.

CONCLUSION

The combined model shows potential in stratifying men with biopsy GGG 1-2 PCa based on the presence of AP at final pathology and outperforms models based solely on clinical or radiomics features. It may be expected to aid urologists in better selecting suitable patients for AS.

Evolution of European prostate cancer screening protocols and summary of ongoing trials

Population-based organised repeated screening for prostate cancer has been found to reduce disease-specific mortality, but with substantial overdiagnosis leading to overtreatment. Although only very few countries have implemented a screening programme on a national level, individual prostate-specific antigen (PSA) testing is common. This opportunistic testing may have little favourable impact, while stressing the side-effects. The classic early detection protocols as were state-of-the-art in the 1990s applied a PSA and digital rectal examination threshold for sextant systematic prostate biopsy, with a fixed interval for re-testing, and limited indication for expectant management. In the three decades since these trials were started, different important improvements have become available in the cascade of screening, indication for biopsy, and treatment. The main developed aspects include: better identification of individuals at risk (using early/baseline PSA, family history, and/or genetic profile), individualised re-testing interval, optimised and individualised starting and stopping age, with gradual invitation at a fixed age rather than invitation of a wider range of age groups, risk stratification for biopsy (using PSA density, risk calculator, magnetic resonance imaging, serum and urine biomarkers, or combinations/sequences), targeted biopsy, transperineal biopsy approach, active surveillance for low-risk prostate cancer, and improved staging of disease. All these developments are suggested to decrease the side-effects of screening, while at least maintaining the advantages, but Level 1 evidence is lacking. The knowledge gained and new developments on early detection are being tested in different prospective screening trials throughout Europe. In addition, the European Union-funded PRostate cancer Awareness and Initiative for Screening in the European Union (PRAISE-U) project will compare and evaluate different screening pilots throughout Europe. Implementation and sustainability will also be addressed. Modern screening approaches may reduce the burden of the second most frequent cause of cancer-related death in European males, while minimising side-effects. Also, less efficacious opportunistic early detection may be indirectly reduced.

Determinants of active surveillance uptake in a diverse population-based cohort of men with low-risk prostate cancer: The Treatment Options in Prostate Cancer Study (TOPCS)

BACKGROUND

Active surveillance (AS) is the preferred strategy for low-risk prostate cancer (LRPC); however, limited data on determinants of AS adoption exist, particularly among Black men.

METHODS

Black and White newly diagnosed (from January 2014 through June 2017) patients with LRPC ≤75 years of age were identified through metro-Detroit and Georgia population-based cancer registries and completed a survey evaluating factors influencing AS uptake.

RESULTS

Among 1688 study participants, 57% chose AS (51% of Black participants, 61% of White) over definitive treatment. In the unadjusted analysis, patient factors associated with initial AS uptake included older age, White race, and higher education. However, after adjusting for covariates, none of these factors was significant predictors of AS uptake. The strongest determinant of AS uptake was the AS recommendation by a urologist (adjusted prevalence ratio, 6.59, 95% CI, 4.84-8.97). Other factors associated with the decision to undergo AS included a shared patient-physician treatment decision, greater prostate cancer knowledge, and residence in metro-Detroit compared with Georgia. Conversely, men whose decision was strongly influenced by the desire to achieve "cure" or "live longer" with treatment and those who perceived their LRPC diagnosis as more serious were less likely to choose AS.

CONCLUSIONS

In this contemporary sample, the majority of patients with newly diagnosed LRPC chose AS. Although the input from their urologists was highly influential, several patient decisional and psychological factors were independently associated with AS uptake. These data shed new light on potentially modifiable factors that can help further increase AS uptake among patients with LRPC.

Medium-term follow up of active surveillance for early prostate cancer at a non-academic institution

OBJECTIVES

To report oncological outcomes of active surveillance (AS) at a single non-academic institution adopting the standardised Prostate Cancer Research International Active Surveillance (PRIAS) protocol.

PATIENTS AND METHODS

Competing risk analyses estimated the incidence of overall mortality, metastases, conversion to treatment, and grade reclassification. The incidence of reclassification and adverse pathological findings at radical prostatectomy were compared between patients fulfilling all PRIAS inclusion criteria vs those not fulfilling at least one.

RESULTS

We analysed 341 men with Grade Group 1 prostate cancer (PCa) followed on AS between 2010 and 2022. There were no PCa deaths, two patients developed distant metastases and were alive at the end of the study period. The 10-year cumulative incidence of metastases was 1.9% (95% confidence interval [CI] 0.33-6.4%). A total of 111 men were reclassified, and 127 underwent definitive treatment. Men not fulfilling at least one PRIAS inclusion criteria (n = 43) had a higher incidence of reclassification (subdistribution hazards ratio 1.73, 95% CI 1.07-2.81; P = 0.03), but similar rates of adverse pathological findings at radical prostatectomy.

CONCLUSION

Metastases in men on AS at a non-academic institution are as rare as those reported in established international cohorts. Men followed without stringent inclusion criteria should be counselled about the higher incidence of reclassification and reassured they can expect rates of adverse pathological findings comparable to those fulfilling all criteria. Therefore, AS should be proposed to all men with low-grade PCa regardless of whether they are followed at academic institutions or smaller community hospitals.

A prospective cohort of men with localized prostate cancer on active surveillance protocol in Hong Kong, China: what did we learn?

This study aimed to report the outcomes of active surveillance (AS) in the management of low-risk prostate cancer (PCa). It recruited 87 men who were prospectively followed up according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol with local adaptation at SH Ho Urology Centre, Prince of Wales Hospital, Hong Kong, China. We investigated the predictors of disease progression and found that baseline prostate-specific antigen density (PSAD) and the presence of the highest Prostate Imaging-Reporting and Data System (PI-RADS) score 5 lesion on magnetic resonance imaging (MRI) are significantly correlated with disease progression. Moreover, men with PSAD >0.2 ng ml -2 or PI-RADS 4 or 5 lesions had significantly worse upgrading-free survival compared to those with PSAD ≤0.2 ng ml -2 and PI-RADS 2 or 3 lesions. The study concludes that AS is a safe and effective management strategy for selected patients to defer radical treatment and that most disease progression can be detected after the first repeated biopsy. The combination of PSAD >0.2 ng ml -2 and PI-RADS 4 or 5 lesions may serve as a useful predictor of early disease progression and provide a guide to optimize follow-up protocols for men in different risk groups.

Applications of Urinary Extracellular Vesicles in the Diagnosis and Active Surveillance of Prostate Cancer

Prostate cancer is the most common non-cutaneous cancer among men in the UK, causing significant health and economic burdens. Diagnosis and risk prognostication can be challenging due to the genetic and clinical heterogeneity of prostate cancer as well as uncertainties in our knowledge of the underlying biology and natural history of disease development. Urinary extracellular vesicles (EVs) are microscopic, lipid bilayer defined particles released by cells that carry a variety of molecular cargoes including nucleic acids, proteins and other molecules. Urine is a plentiful source of prostate-derived EVs. In this narrative review, we summarise the evidence on the function of urinary EVs and their applications in the evolving field of prostate cancer diagnostics and active surveillance. EVs are implicated in the development of all hallmarks of prostate cancer, and this knowledge has been applied to the development of multiple diagnostic tests, which are largely based on RNA and miRNA. Common gene probes included in multi-probe tests include PCA3 and ERG, and the miRNAs miR-21 and miR-141. The next decade will likely bring further improvements in the diagnostic accuracy of biomarkers as well as insights into molecular biological mechanisms of action that can be translated into opportunities in precision uro-oncology.

Shifting the paradigm in the management of early prostate cancer

Outcomes from active surveillance have clearly shown that it is the optimal method of managing many early prostate cancers. Yet, clinician training and healthcare systems are still primarily focused on the "need to treat". This comment explores the challenges and resource issues in future implementation of high-quality surveillance programmes.

Using active surveillance for Gleason 7 (3+4) prostate cancer: A narrative review

The interest in broadening the application of active surveillance (AS) has been increasing, encompassing patients who may not strictly adhere to the conventional criteria for low-risk prostate cancer (PCa), particularly those diagnosed with small-volume Gleason grade group 2 disease. Nonetheless, accurately identifying individuals with low intermediate-risk PCa who can safely undergo AS without facing disease progression remains a challenge.This review aims to delve into the progression of this evolving trend specifically within this cohort of men, while also examining strategies aimed at minimizing irreversible disease advancement. Additionally, we address the criteria for patient selection, recommended followup schedules, and the indicators prompting intervention.

Prospective comparison of restriction spectrum imaging and non-invasive biomarkers to predict upgrading on active surveillance prostate biopsy

BACKGROUND

Protocol-based active surveillance (AS) biopsies have led to poor compliance. To move to risk-based protocols, more accurate imaging biomarkers are needed to predict upgrading on AS prostate biopsy. We compared restriction spectrum imaging (RSI-MRI) generated signal maps as a biomarker to other available non-invasive biomarkers to predict upgrading or reclassification on an AS biopsy.

METHODS

We prospectively enrolled men on prostate cancer AS undergoing repeat biopsy from January 2016 to June 2019 to obtain an MRI and biomarkers to predict upgrading. Subjects underwent a prostate multiparametric MRI and a short duration, diffusion-weighted enhanced MRI called RSI to generate a restricted signal map along with evaluation of 30 biomarkers (14 clinico-epidemiologic features, 9 molecular biomarkers, and 7 radiologic-associated features). Our primary outcome was upgrading or reclassification on subsequent AS prostate biopsy. Statistical analysis included operating characteristic improvement using AUROC and AUPRC.

RESULTS

The individual biomarker with the highest area under the receiver operator characteristic curve (AUC) was RSI-MRI (AUC = 0.84; 95% CI: 0.71-0.96). The best non-imaging biomarker was prostate volume-corrected Prostate Health Index density (PHI, AUC = 0.68; 95% CI: 0.53-0.82). Non-imaging biomarkers had a negligible effect on predicting upgrading at the next biopsy but did improve predictions of overall time to progression in AS.

CONCLUSIONS

RSI-MRI, PIRADS, and PHI could improve the predictive ability to detect upgrading in AS. The strongest predictor of clinically significant prostate cancer on AS biopsy was RSI-MRI signal output.

The PRECISE Recommendations for Prostate MRI in Patients on Active Surveillance for Prostate Cancer: A Critical Review

The Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) recommendations were published in 2016 to standardize the reporting of MRI examinations performed to assess for disease progression in patients on active surveillance for prostate cancer. Although a limited number of studies have reported outcomes from use of PRECISE in clinical practice, the available studies have demonstrated PRECISE to have high pooled NPV but low pooled PPV for predicting progression. Our experience in using PRECISE in clinical practice at two teaching hospitals has highlighted issues with its application and areas requiring clarification. This Clinical Perspective critically appraises PRECISE on the basis of this experience, focusing on the system's key advantages and disadvantages and exploring potential changes to improve the system's utility. These changes include consideration of image quality when applying PRECISE scoring, incorporation of quantitative thresholds for disease progression, adoption of a PRECISE 3F sub-category for progression not qualifying as substantial, and comparisons with both the baseline and most recent prior examinations. Items requiring clarification include derivation of a patient-level score in patients with multiple lesions, intended application of PRECISE score 5 (i.e., if requiring development of disease that is no longer organ-confined), and categorization of new lesions in patients with prior MRI-invisible disease.

Active Surveillance for Prostate Cancer: Past, Current, and Future Trends

In response to the rising incidence of indolent, low-risk prostate cancer (PCa) due to increased prostate-specific antigen (PSA) screening in the 1990s, active surveillance (AS) emerged as a treatment modality to combat overtreatment by delaying or avoiding unnecessary definitive treatment and its associated morbidity. AS consists of regular monitoring of PSA levels, digital rectal exams, medical imaging, and prostate biopsies, so that definitive treatment is only offered when deemed necessary. This paper provides a narrative review of the evolution of AS since its inception and an overview of its current landscape and challenges. Although AS was initially only performed in a study setting, numerous studies have provided evidence for the safety and efficacy of AS which has led guidelines to recommend it as a treatment option for patients with low-risk PCa. For intermediate-risk disease, AS appears to be a viable option for those with favourable clinical characteristics. Over the years, the inclusion criteria, follow-up schedule and triggers for definitive treatment have evolved based on the results of various large AS cohorts. Given the burdensome nature of repeat biopsies, risk-based dynamic monitoring may further reduce overtreatment by avoiding repeat biopsies in selected patients.

Beyond diagnosis: is there a role for radiomics in prostate cancer management?

The role of imaging in pretreatment staging and management of prostate cancer (PCa) is constantly evolving. In the last decade, there has been an ever-growing interest in radiomics as an image analysis approach able to extract objective quantitative features that are missed by human eye. However, most of PCa radiomics studies have been focused on cancer detection and characterisation. With this narrative review we aimed to provide a synopsis of the recently proposed potential applications of radiomics for PCa with a management-based approach, focusing on primary treatments with curative intent and active surveillance as well as highlighting on recurrent disease after primary treatment. Current evidence is encouraging, with radiomics and artificial intelligence appearing as feasible tools to aid physicians in planning PCa management. However, the lack of external independent datasets for validation and prospectively designed studies casts a shadow on the reliability and generalisability of radiomics models, delaying their translation into clinical practice.Key points• Artificial intelligence solutions have been proposed to streamline prostate cancer radiotherapy planning.• Radiomics models could improve risk assessment for radical prostatectomy patient selection.• Delta-radiomics appears promising for the management of patients under active surveillance.• Radiomics might outperform current nomograms for prostate cancer recurrence risk assessment.• Reproducibility of results, methodological and ethical issues must still be faced before clinical implementation.

Time series radiomics for the prediction of prostate cancer progression in patients on active surveillance

Serial MRI is an essential assessment tool in prostate cancer (PCa) patients enrolled on active surveillance (AS). However, it has only moderate sensitivity for predicting histopathological tumour progression at follow-up, which is in part due to the subjective nature of its clinical reporting and variation among centres and readers. In this study, we used a long short-term memory (LSTM) recurrent neural network (RNN) to develop a time series radiomics (TSR) predictive model that analysed longitudinal changes in tumour-derived radiomic features across 297 scans from 76 AS patients, 28 with histopathological PCa progression and 48 with stable disease. Using leave-one-out cross-validation (LOOCV), we found that an LSTM-based model combining TSR and serial PSA density (AUC 0.86 [95% CI: 0.78-0.94]) significantly outperformed a model combining conventional delta-radiomics and delta-PSA density (0.75 [0.64-0.87]; p = 0.048) and achieved comparable performance to expert-performed serial MRI analysis using the Prostate Cancer Radiologic Estimation of Change in Sequential Evaluation (PRECISE) scoring system (0.84 [0.76-0.93]; p = 0.710). The proposed TSR framework, therefore, offers a feasible quantitative tool for standardising serial MRI assessment in PCa AS. It also presents a novel methodological approach to serial image analysis that can be used to support clinical decision-making in multiple scenarios, from continuous disease monitoring to treatment response evaluation. KEY POINTS: •LSTM RNN can be used to predict the outcome of PCa AS using time series changes in tumour-derived radiomic features and PSA density. •Using all available TSR features and serial PSA density yields a significantly better predictive performance compared to using just two time points within the delta-radiomics framework. •The concept of TSR can be applied to other clinical scenarios involving serial imaging, setting out a new field in AI-driven radiology research.

Interaction of MRI and active surveillance in prostate cancer: Time to re-evaluate the active surveillance inclusion criteria

Currently available data from long-running single- and multi-center active surveillance (AS) studies show that AS has excellent cancer-specific survival rates. For AS to be effective the 'right' patients should be selected for which up until 5-to-10 years ago systematic prostate biopsies were used. Because the systematic prostate strategy relies on sampling efficiency for the detection of prostate cancer (PCa), it is subject to sampling error. Due to this sampling error, many of the Gleason 3+3 PCas that were included on AS in the early days and were classified as low-risk, may in fact have had a higher Gleason score. Subsequently, AS-criteria were more strict to overcome or limit the number of men missing the potential window of curability in case their tumor would be reclassified. Five to ten years ago the prostate biopsy landscape changed drastically by the addition of magnetic resonance imaging (MRI) into the diagnostic PCa-care pathway, which has by now trickled down into the EAU guidelines. At the moment, the EAU guidelines recommend performing a (multi-parametric) MRI before prostate biopsy and combine systematic and targeted prostate biopsy when the MRI is positive (i.e. PIRADS ≥3). So because of the introduction of the MRI into the diagnostic PCa-care pathway, literature is showing that more Gleason 3+4 PCas are being diagnosed. But can it not be that the inclusion of MRI into the diagnostic PCa-care pathway causes risk inflation, resulting in men earlier eligible for AS, now being labelled ineligible for AS? Would it not be possible to include these current Gleason 3+4 PCas on AS? The authors hypothesize that the improved accuracy that comes with the introduction of MRI into the diagnostic PCa-care pathway permits to widen both the AS-inclusion and follow-up criteria. Maintaining our inclusion criteria for AS from the systematic biopsy era will unnecessarily and undesirably expose patients to the increased risk of overtreatment. The evidence behind the addition of MRI-targeted biopsies to systematic biopsies calls upon the re-evaluation of the AS inclusion criteria and research from one-size-fits-all protocols used so far, into the direction of more dynamic and individual risk-based AS-approaches.

Pathological Effects of Apalutamide in Lower-risk Prostate Cancer: Results From a Phase II Clinical Trial

PURPOSE

Active surveillance is a safe and effective strategy for men with lower-risk prostate cancer who want to avoid local therapy; however, many patients on active surveillance progress to active treatment (eg, prostatectomy or radiation). We hypothesized that apalutamide would decrease active surveillance attrition rates through downstaging low-grade tumors.

MATERIALS AND METHODS

This was an open-label, single-arm, phase II study testing 90 days of oral apalutamide 240 mg daily in men with low- to intermediate-risk prostate cancer on active surveillance. The primary objective was to determine the percentage of patients with a negative biopsy immediately following treatment. Secondary objectives were to assess long-term clinical outcomes, quality of life, safety, and biomarkers of response/resistance.

RESULTS

Twenty-three patients enrolled and 22 completed 90 days of apalutamide with post-treatment biopsy. Fifteen (65%) had Grade Group 1 disease, and all others had Grade Group 2 disease. Seven (30%) had favorable- to intermediate-risk disease. Of 22 evaluable patients, 13 (59%) had no residual cancer on post-treatment biopsy. The median time to first positive biopsy was 364 days (95% CI: 91-742 days). The impact of apalutamide on quality of life was minimal and transient. Decipher risk classifier revealed a greater number of negative post-treatment biopsies in those with higher baseline genomic risk score (P = .01).

CONCLUSIONS

The negative repeat biopsy rate following 90 days of apalutamide was high in men with prostate cancer followed on active surveillance. Apalutamide was safe, well tolerated, and had minimal impact on quality of life. Randomized studies evaluating the effects of apalutamide in men enrolled on active surveillance are warranted.

Long-term Health-related Quality of Life in Patients on Active Surveillance for Prostate Cancer: A Systematic Review

CONTEXT

Active surveillance (AS) represents the preferred treatment option in patients with low-risk prostate cancer. Optimised patient selection has enabled more patients to be managed with AS for a longer time. Thus, there is growing interest in its effect on long-term quality of life compared with interventional management.

OBJECTIVE

To perform a systematic review evaluating the long-term patient-reported outcomes regarding mental health, and sexual and urinary function in patients on AS.

EVIDENCE ACQUISITION

We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. We included series assessing validated patient-reported outcomes of health-related quality of life, and sexual and urinary function in AS patients followed up for at least 5 yr.

EVIDENCE SYNTHESIS

Our search yielded 1854 citations, including 19 papers involving 3643 patients on AS, 14 651 patients receiving surgery or radiotherapy, and 2478 controls without prostate cancer. In ten studies, major differences were observed in sexual and urinary symptoms between groups, such as better sexual function and fewer irritative urinary symptoms in patients on AS, though overall functional outcomes were comparable. In all studies, health-related quality of life for patients on AS was better than, or similar to, that for patients who had undergone surgery or radiotherapy and comparable with that for individuals without cancer.

CONCLUSIONS

We observed differences in specific functional outcomes between patients on AS and surgery or radiotherapy, ≥5 yr after treatment. Patients on AS reported good quality of life, similar to that in individuals without prostate cancer. AS should continue to be a recommended management strategy for appropriately selected patients.

PATIENT SUMMARY

Active surveillance is an accepted pathway for patients with low-risk localised prostate cancer. Previous literature has shown that it did not negatively affect short-term quality of life. This review finds that long-term quality of life for these patients is similar to that for people without prostate cancer.

Best Current Practice and Research Priorities in Active Surveillance for Prostate Cancer-A Report of a Movember International Consensus Meeting

BACKGROUND

Active surveillance (AS) is recommended for low-risk and some intermediate-risk prostate cancer. Uptake and practice of AS vary significantly across different settings, as does the experience of surveillance-from which tests are offered, and to the levels of psychological support.

OBJECTIVE

To explore the current best practice and determine the most important research priorities in AS for prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

A formal consensus process was followed, with an international expert panel of purposively sampled participants across a range of health care professionals and researchers, and those with lived experience of prostate cancer. Statements regarding the practice of AS and potential research priorities spanning the patient journey from surveillance to initiating treatment were developed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Panel members scored each statement on a Likert scale. The group median score and measure of consensus were presented to participants prior to discussion and rescoring at panel meetings. Current best practice and future research priorities were identified, agreed upon, and finally ranked by panel members.

RESULTS AND LIMITATIONS

There was consensus agreement that best practice includes the use of high-quality magnetic resonance imaging (MRI), which allows digital rectal examination (DRE) to be omitted, that repeat standard biopsy can be omitted when MRI and prostate-specific antigen (PSA) kinetics are stable, and that changes in PSA or DRE should prompt MRI ± biopsy rather than immediate active treatment. The highest ranked research priority was a dynamic, risk-adjusted AS approach, reducing testing for those at the least risk of progression. Improving the tests used in surveillance, ensuring equity of access and experience across different patients and settings, and improving information and communication between and within clinicians and patients were also high priorities. Limitations include the use of a limited number of panel members for practical reasons.

CONCLUSIONS

The current best practice in AS includes the use of high-quality MRI to avoid DRE and as the first assessment for changes in PSA, with omission of repeat standard biopsy when PSA and MRI are stable. Development of a robust, dynamic, risk-adapted approach to surveillance is the highest research priority in AS for prostate cancer.

PATIENT SUMMARY

A diverse group of experts in active surveillance, including a broad range of health care professionals and researchers and those with lived experience of prostate cancer, agreed that best practice includes the use of high-quality magnetic resonance imaging, which can allow digital rectal examination and some biopsies to be omitted. The highest research priority in active surveillance research was identified as the development of a dynamic, risk-adjusted approach.

Developing machine learning algorithms for dynamic estimation of progression during active surveillance for prostate cancer

Active Surveillance (AS) for prostate cancer is a management option that continually monitors early disease and considers intervention if progression occurs. A robust method to incorporate “live” updates of progression risk during follow-up has hitherto been lacking. To address this, we developed a deep learning-based individualised longitudinal survival model using Dynamic-DeepHit-Lite (DDHL) that learns data-driven distribution of time-to-event outcomes. Further refining outputs, we used a reinforcement learning approach (Actor-Critic) for temporal predictive clustering (AC-TPC) to discover groups with similar time-to-event outcomes to support clinical utility. We applied these methods to data from 585 men on AS with longitudinal and comprehensive follow-up (median 4.4 years). Time-dependent C-indices and Brier scores were calculated and compared to Cox regression and landmarking methods. Both Cox and DDHL models including only baseline variables showed comparable C-indices but the DDHL model performance improved with additional follow-up data. With 3 years of data collection and 3 years follow-up the DDHL model had a C-index of 0.79 (±0.11) compared to 0.70 (±0.15) for landmarking Cox and 0.67 (±0.09) for baseline Cox only. Model calibration was good across all models tested. The AC-TPC method further discovered 4 distinct outcome-related temporal clusters with distinct progression trajectories. Those in the lowest risk cluster had negligible progression risk while those in the highest cluster had a 50% risk of progression by 5 years. In summary, we report a novel machine learning approach to inform personalised follow-up during active surveillance which improves predictive power with increasing data input over time.

Active Surveillance for Men Younger than 60 Years or with Intermediate-risk Localized Prostate Cancer. Descriptive Analyses of Clinical Practice in the Movember GAP3 Initiative

Background

Active surveillance (AS) is a management option for men diagnosed with low-risk prostate cancer. Opinions differ on whether it is safe to include young men (≤60 yr) or men with intermediate-risk disease.

Objective

To assess whether reasons for discontinuation, treatment choice after AS, and adverse pathology at radical prostatectomy (RP; N1, or ≥GG3, or ≥pT3) differ for men ≤60 yr or those with European Association of Urology (EAU) intermediate-risk disease from those for men >60 yr or those with EAU low-risk disease.

Design setting and participants

We analyzed data from 5411 men ≤60 yr and 14 959 men >60 yr, 14 064 men with low-risk cancer, and 2441 men with intermediate-risk cancer, originating from the GAP3 database (21 169 patients/27 cohorts worldwide).

Outcome measurements and statistical analysis

Cumulative incidence curves were used to estimate the rates of AS discontinuation and treatment choice.

Results and limitations

The probability of discontinuation of AS due to disease progression at 5 yr was similar for men aged ≤60 yr (22%) and those >60 yr (25%), as well as those of any age with low-risk disease (24%) versus those with intermediate-risk disease (24%). Men with intermediate-risk disease are more prone to discontinue AS without evidence of progression than men with low-risk disease (at 1/5 yr: 5.9%/14.2% vs 2.0%/8.8%). Adverse pathology at RP was observed in 32% of men ≤60 yr compared with 36% of men >60 yr (p = 0.029), and in 34% with low-risk disease compared with 40% with intermediate-risk disease (p = 0.048).

Conclusions

Our descriptive analysis of AS practices worldwide showed that the risk of progression during AS is similar across the age and risk groups studied. The proportion of adverse pathology was higher among men >60 yr than among men ≤60 yr. These results suggest that men ≤60 yr and those with EAU intermediate-risk disease should not be excluded from opting for AS as initial management.

Patient summary

Data from 27 international centers reflecting daily clinical practice suggest that younger men or men with intermediate-risk prostate cancer do not hold greater risk for disease progression during active surveillance.

Why do men with prostate cancer discontinue active surveillance for definitive treatment? A mixed methods investigation

Objectives

To explore the personal and/or medical reasons patients on active surveillance (AS) have, or consider having, further definitive treatment for their prostate cancer. Research suggests up to 50% of patients on AS will discontinue within 5 years, though reasons for discontinuation from the patient's perspective is under‐explored.

Methods

Prostate cancer patients who were or had been on AS for at least 6 months were recruited. A questionnaire assessed reasons for receiving/considering definitive treatment and the extent to which reasons were personal or medical. Clinical information was extracted from a state‐level population registry. A subset of participants were interviewed to further explore questionnaire responses.

Results

One‐hundred and‐three individuals completed the survey; 33 were also interviewed. Fifty‐four survey participants (52%) had discontinued AS for definitive treatment. Common reasons for discontinuation were evidence of disease progression, doctor recommendation, desire to act, and fear of progression. Many participants who considered or had treatment reported weighing medical and personal factors equally in their decision. Interview participants described strongly considering any amount of disease progression and personal factors such as fear of progression, family concerns, and adverse vicarious experiences when deciding whether to pursue treatment.

Conclusion

Both medical and personal factors are considered when deciding whether to discontinue AS. Identifying predictors of discontinuation is essential for informing supportive care services to improve AS management.

A Feasibility Study of the Therapeutic Response and Durability of Short-term Androgen-targeted Therapy in Early Prostate Cancer Managed with Surveillance: The Therapeutics in Active Prostate Surveillance (TAPS01) Study

Background

Active surveillance (AS) is a preferred management option for men with prostate cancer with favourable prognosis. However, nearly half of men on AS switch to treatment within 5 years, so therapeutic strategies to prevent or delay disease progression could be considered. The androgen receptor is the pre-eminent oncogenic driver in prostate cancer.

Objective

To explore image-based tumour responses and the patient impact of short-duration androgen-targeted therapy (ATT) to abrogate disease progression during AS.

Design, setting, and participants

Men on AS with Cambridge Prognostic Group 1 & 2 (low and favourable intermediate risk) prostate cancer and lesions visible on magnetic resonance imaging (MRI) were recruited to an open-label, single-centre, phase 2 feasibility study of short-term ATT (the TAPS01 study).

Intervention

Apalutamide 240 mg was administered for 90 days.

Outcome measurements and statistical analysis

MRI-measured tumour volume (TV), gland volume (GV), and the TV/GV ratio were calculated at baseline, at day 90 (end of treatment), and at 6- and 18-month follow-up. Quality of life metrics were measured at day 0, day 90, and 6 weeks after ATT.

Results and limitations

Eleven patients (40% of eligible men approached) agreed to participate, of whom nine completed treatment. At day 90, the median percentage reduction was −38.2% (range −51.8% to −23.5%) for GV, −54.2% (range −74.1% to −13.8%) for TV, and −27.2% (range −61.5% to −7.5%) for TV/GV (all p < 0.0001). At 6 mo, while GV had returned to baseline (p = 0.95) both TV (−31.9%; p = 0.0007) and TV/GV (−28.7%; p = 0.0009) remained significantly reduced. This reduction was sustained at 18 months (TV −18%, TV/GV −23.8%; p = 0.01). European Organization for Research and Treatment of Cancer QoL core 30-item questionnaire scores for global, physical, role, and social functioning decreased during treatment, but all were recovering by 6 weeks. EQ-VAS scores were unchanged compared to baseline.

Conclusions

TAPS01 has demonstrated feasibility and patient tolerability for short-term ATT in men on AS. Our data suggest a selective and durable antitumour effect in the short term and support a larger-scale randomised trial.

Patient summary

We investigated the feasibility of short-term treatment with an androgen inhibitor to prevent or delay disease progression for men on active surveillance for prostate cancer. Results for a small group of patients show that 90-day treatment led to a sustained decrease in tumour volume over 18 months. The findings warrant a larger clinical trial for this approach, which could allow patients to delay or even avoid longer-term active treatments.

Independent validation of a pre-specified four-kallikrein marker model for prediction of adverse pathology and biochemical recurrence

BACKGROUND

Accurate markers for prostate cancer (PC) risk stratification could aid decision-making for initial management strategies. The 4Kscore has an undefined role in predicting outcomes after radical prostatectomy (RP).

METHODS

We included 1476 patients with 4Kscore measured prior to RP at two institutions. The 4Kscore was assessed for prediction of adverse pathology at RP and biochemical recurrence (BCR) relative to a clinical model. We pre-specified that all analyses would be assessed in biopsy Grade Group 1 (GG1) or 2 (GG2) PC patients, separately.

RESULTS

The 4Kscore increased discrimination for adverse pathology in all patients (delta area under the receiver operative curve (AUC) 0.009, 95% confidence interval (CI) 0.002, 0.016; clinical model AUC 0.767), driven by GG1 (delta AUC 0.040, 95% CI 0.006, 0.073) rather than GG2 patients (delta AUC 0.005, 95% CI -0.012, 0.021). Adding 4Kscore improved prediction of BCR in all patients (delta C-index 0.014, 95% CI 0.007, 0.021; preop-BCR nomogram C-index 0.738), again with larger changes in GG1 than in GG2.

CONCLUSIONS

This study validates prior investigations on the use of 4Kscore in men with biopsy-confirmed PC. Men with GG1 PC and a high 4Kscore may benefit from additional testing to guide treatment selection. Further research is warranted regarding the value of the 4Kscore in men with biopsy GG2 PC.

Unified model involving genomics, magnetic resonance imaging and prostate-specific antigen density outperforms individual co-variables at predicting biopsy upgrading in patients on active surveillance for low risk prostate cancer

BACKGROUND

Active surveillance (AS) is the reference standard treatment for the management of low risk prostate cancer (PCa). Accurate assessment of tumor aggressiveness guides recruitment to AS programs to avoid conservative treatment of intermediate and higher risk patients. Nevertheless, underestimating the disease risk may occur in some patients recruited, with biopsy upgrading and the concomitant potential for delayed treatment.

AIM

To evaluate the accuracy of mpMRI and GPS for the prediction of biopsy upgrading during active surveillance (AS) management of prostate cancer (PCa).

METHOD

A retrospective analysis was performed on 144 patients recruited to AS from October 2013 to December 2020. Median follow was 4.8 (IQR 3.6, 6.3) years. Upgrading was defined as upgrading to biopsy grade group ≥2 on follow up biopsies. Cox proportional hazard regression was used to investigate the effect of PSA density (PSAD), baseline Prostate Imaging-Reporting and Data System (PI-RADS) v2.1 score and GPS on upgrading. Time-to-event outcome, defined as upgrading, was estimated using the Kaplan-Meier method with log-rank test.

RESULTS

Overall rate of upgrading was 31.9% (n = 46). PSAD was higher in the patients who were upgraded (0.12 vs. 0.08 ng/ml2 , p = .005), while no significant difference was present for median GPS in the overall cohort (overall median GPS 21; 22 upgrading vs. 20 no upgrading, p = .2044). On univariable cox proportional hazard regression analysis, the factors associated with increased risk of biopsy upgrading were PSA (HR = 1.30, CI 1.16-1.47, p = <.0001), PSAD (HR = 1.08, CI 1.05-1.12, p = <.0001) and higher PI-RADS score (HR = 3.51, CI 1.56-7.91, p = .0024). On multivariable cox proportional hazard regression analysis, only PSAD (HR = 1.10, CI 1.06-1.14, p = <.001) and high PI-RADS score (HR = 4.11, CI 1.79-9.44, p = .0009) were associated with upgrading. A cox regression model combining these three clinical features (PSAD ≥0.15 ng/ml2 at baseline, PI-RADS Score and GPS) yielded a concordance index of 0.71 for the prediction of upgrading.

CONCLUSION

In this study PSAD has higher accuracy over baseline PI-RADS score and GPS score for the prediction of PCa upgrading during AS. However, combined use of PSAD, GPS and PI-RADS Score yielded the highest predictive ability with a concordance index of 0.71.

Serial changes in tumour measurements and apparent diffusion coefficients in prostate cancer patients on active surveillance with and without histopathological progression

OBJECTIVE

To analyse serial changes in MRI-derived tumour measurements and apparent diffusion coefficient (ADC) values in prostate cancer (PCa) patients on active surveillance (AS) with and without histopathological disease progression.

METHODS

This study included AS patients with biopsy-proven PCa with a minimum of two consecutive MR examinations and at least one repeat targeted biopsy. Tumour volumes, largest axial two-dimensional (2D) surface areas, and maximum diameters were measured on T2 weighted images (T2WI). ADC values were derived from the whole lesions, 2D areas, and small-volume regions of interest (ROIs) where tumours were most conspicuous. Areas under the ROC curve (AUCs) were calculated for combinations of T2WI and ADC parameters with optimal specificity and sensitivity.

RESULTS

60 patients (30 progressors and 30 non-progressors) were included. In progressors, T2WI-derived tumour volume, 2D surface area, and maximum tumour diameter had a median increase of +99.5%,+55.3%, and +21.7% compared to +29.2%,+8.1%, and +6.9% in non-progressors (p < 0.005 for all). Follow-up whole-volume and small-volume ROIs ADC values were significantly reduced in progressors (-11.7% and -9.5%) compared to non-progressors (-6.1% and -1.6%) (p < 0.05 for both). The combined AUC of a relative increase in maximum tumour diameter by 20% and reduction in small-volume ADC by 10% was 0.67.

CONCLUSION

AS patients show significant differences in tumour measurements and ADC values between those with and without histopathological disease progression.

ADVANCES IN KNOWLEDGE

This paper proposes specific clinical cut-offs for T2WI-derived maximum tumour diameter (+20%) and small-volume ADC (-10%) to predict histopathological PCa progression on AS and supplement subjective serial MRI assessment.

Five-year follow-up study of a population-based prospective cohort of men with low-risk prostate cancer: the treatment options in prostate cancer study (TOPCS): study protocol

INTRODUCTION

Active surveillance (AS) is recommended for men with low-risk prostate cancer (LRPC) to reduce overtreatment and to maintain patients' quality of life (QOL). However, whether African American (AA) men can safely undergo AS is controversial due to concerns of more aggressive disease and lack of empirical data on the safety and effectiveness of AS in this population. Withholding of AS may lead to a lost opportunity for improving survivorship in AA men. In this study, peer-reviewed and funded by the US Department of Defense, we will assess whether AS is an equally effective and safe management option for AA as it is for White men with LRPC.

METHODS AND ANALYSIS

The project extends follow-up of a large contemporary population-based cohort of LRPC patients (n=1688) with a high proportion of AA men (~20%) and well-characterised baseline and 2-year follow-up data. The objectives are to (1) determine any racial differences in AS adherence, switch rate from AS to curative treatment and time to treatment over 5 years after diagnosis, (2) compare QOL among AS group and curative treatment group over time, overall and by race and (3) evaluate whether reasons for switching from AS to curative treatment differ by race. Validation of survey responses related to AS follow-up procedures is being conducted through medical record review. We expect to obtain 5-year survey from ~900 (~20% AA) men by the end of this study to have sufficient power. Descriptive and inferential statistical techniques will be used to examine racial differences in AS adherence, effectiveness and QOL.

ETHICS AND DISSEMINATION

The parent and current studies were approved by the Institutional Review Boards at Wayne State University and Emory University. Since it is an observational study, ethical or safety risks are low. We will disseminate our findings to relevant conferences and peer-reviewed journals.

Diagnostic Accuracy of Contemporary Selection Criteria in Prostate Cancer Patients Eligible for Active Surveillance: A Bayesian Network Meta-Analysis

Background

Several active surveillance (AS) criteria have been established to screen insignificant prostate cancer (insigPCa, defined as organ confined, low grade and small volume tumors confirmed by postoperative pathology). However, their comparative diagnostic performance varies. The aim of this study was to compare the diagnostic accuracy of contemporary AS criteria and validate the absolute diagnostic odds ratio (DOR) of optimal AS criteria.

Methods

First, we searched Pubmed and performed a Bayesian network meta-analysis (NMA) to compare the diagnostic accuracy of contemporary AS criteria and obtained a relative ranking. Then, we searched Pubmed again to perform another meta-analysis to validate the absolute DOR of the top-ranked AS criteria derived from the NMA with two endpoints: insigPCa and favorable disease (defined as organ confined, low grade tumors). Subgroup and meta-regression analyses were conducted to identify any potential heterogeneity in the results. Publication bias was evaluated.

Results

Seven eligible retrospective studies with 3,336 participants were identified for the NMA. The diagnostic accuracy of AS criteria ranked from best to worst, was as follows: Epstein Criteria (EC), Yonsei criteria, Prostate Cancer Research International: Active Surveillance (PRIAS), University of Miami (UM), University of California-San Francisco (UCSF), Memorial Sloan-Kettering Cancer Center (MSKCC), and University of Toronto (UT). I² = 50.5%, and sensitivity analysis with different insigPCa definitions supported the robustness of the results. In the subsequent meta-analysis of DOR of EC, insigPCa and favorable disease were identified as endpoints in ten and twenty-two studies, respectively. The pooled DOR for insigPCa and favorable disease were 0.44 (95%CI, 0.31–0.58) and 0.66 (95%CI, 0.61–0.71), respectively. According to a subgroup analysis, the DOR for favorable disease was significantly higher in US institutions than that in other regions. No significant heterogeneity or evidence of publication bias was identified.

Conclusions

Among the seven AS criteria evaluated in this study, EC was optimal for positively identifying insigPCa patients. The pooled diagnostic accuracy of EC was 0.44 for insigPCa and 0.66 when a more liberal endpoint, favorable disease, was used.

Systematic Review Registration

[https://www.crd.york.ac.uk/prospero/], PROSPERO [CRD42020157048].

Hyperpolarised 13C-MRI identifies the emergence of a glycolytic cell population within intermediate-risk human prostate cancer

Hyperpolarised magnetic resonance imaging (HP 13C-MRI) is an emerging clinical technique to detect [1-13C]lactate production in prostate cancer (PCa) following intravenous injection of hyperpolarised [1-13C]pyruvate. Here we differentiate clinically significant PCa from indolent disease in a low/intermediate-risk population by correlating [1-13C]lactate labelling on MRI with the percentage of Gleason pattern 4 (%GP4) disease. Using immunohistochemistry and spatial transcriptomics, we show that HP 13C-MRI predominantly measures metabolism in the epithelial compartment of the tumour, rather than the stroma. MRI-derived tumour [1-13C]lactate labelling correlated with epithelial mRNA expression of the enzyme lactate dehydrogenase (LDHA and LDHB combined), and the ratio of lactate transporter expression between the epithelial and stromal compartments (epithelium-to-stroma MCT4). We observe similar changes in MCT4, LDHA, and LDHB between tumours with primary Gleason patterns 3 and 4 in an independent TCGA cohort. Therefore, HP 13C-MRI can metabolically phenotype clinically significant disease based on underlying metabolic differences in the epithelial and stromal tumour compartments.

Treatment in the absence of disease reclassification among men on active surveillance for prostate cancer

BACKGROUND

Maintaining men on active surveillance for prostate cancer can be challenging. Although most men who eventually undergo treatment have experienced clinical progression, a smaller subset elects treatment in the absence of disease reclassification. This study sought to understand factors associated with treatment in a large, contemporary, prospective cohort.

METHODS

This study identified 1789 men in the Canary Prostate Cancer Active Surveillance Study cohort enrolled as of 2020 with a median follow-up of 5.6 years. Clinical and demographic data as well as information on patient-reported quality of life and urinary symptoms were used in multivariable Cox proportional hazards regression models to identify factors associated with the time to treatment RESULTS: Within 4 years of their diagnosis, 33% of men (95% confidence interval [CI], 30%-35%) underwent treatment, and 10% (95% CI, 9%-12%) were treated in the absence of reclassification. The most significant factor associated with any treatment was an increasing Gleason grade group (adjusted hazard ratio [aHR], 14.5; 95% CI, 11.7-17.9). Urinary quality-of-life scores were associated with treatment without reclassification (aHR comparing "mostly dissatisfied/terrible" with "pleased/mixed," 2.65; 95% CI, 1.54-4.59). In a subset analysis (n = 692), married men, compared with single men, were more likely to undergo treatment in the absence of reclassification (aHR, 2.63; 95% CI, 1.04-6.66).

CONCLUSIONS

A substantial number of men with prostate cancer undergo treatment in the absence of clinical changes in their cancers, and quality-of-life changes and marital status may be important factors in these decisions.

LAY SUMMARY

This analysis of men on active surveillance for prostate cancer shows that approximately 1 in 10 men will decide to be treated within 4 years of their diagnosis even if their cancer is stable. These choices may be related in part to quality-or-life or spousal concerns.

Genetic Factors Associated with Prostate Cancer Conversion from Active Surveillance to Treatment

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

Prostate Cancer Patients Under Active Surveillance with a Suspicious Magnetic Resonance Imaging Finding Are at Increased Risk of Needing Treatment: Results of the Movember Foundation's Global Action Plan Prostate Cancer Active Surveillance (GAP3) Consortium

BACKGROUND

The inclusion criterion for active surveillance (AS) is low- or intermediate-risk prostate cancer. The predictive value of the presence of a suspicious lesion at magnetic resonance imaging (MRI) at the time of inclusion is insufficiently known.

OBJECTIVE

To evaluate the percentage of patients needing active treatment stratified by the presence or absence of a suspicious lesion at baseline MRI.

DESIGN SETTING AND PARTICIPANTS

A retrospective analysis of the data from the multicentric AS GAP3 Consortium database was conducted. The inclusion criteria were men with grade group (GG) 1 or GG 2 prostate cancer combined with prostate-specific antigen <20 ng/ml. We selected a subgroup of patients who had MRI at baseline and for whom MRI results and targeted biopsies were used for AS eligibility. Suspicious MRI was defined as an MRI lesion with Prostate Imaging Reporting and Data System (PI-RADS)/Likert ≥3 and for which targeted biopsies did not exclude the patient for AS.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was treatment free survival (FS). The secondary outcomes were histological GG progression FS and continuation of AS (discontinuation FS).

RESULTS AND LIMITATIONS

The study cohort included 2119 patients (1035 men with nonsuspicious MRI and 1084 with suspicious MRI) with a median follow-up of 23 (12-43) mo. For the whole cohort, 3-yr treatment FS was 71% (95% confidence interval [CI]: 69-74). For nonsuspicious MRI and suspicious MRI groups, 3-yr treatment FS rates were, respectively, 80% (95% CI: 77-83) and 63% (95% CI: 59-66). Active treatment (hazard ratio [HR] = 2.0, p < 0.001), grade progression (HR = 1.9, p < 0.001), and discontinuation of AS (HR = 1.7, p < 0.001) were significantly higher in the suspicious MRI group than in the nonsuspicious MRI group.

CONCLUSIONS

The risks of switching to treatment, histological progression, and AS discontinuation are higher in cases of suspicious MRI at inclusion.

PATIENT SUMMARY

Among men with low- or intermediate-risk prostate cancer who choose active surveillance, those with suspicious magnetic resonance imaging (MRI) at the time of inclusion in active surveillance are more likely to show switch to treatment than men with nonsuspicious MRI.

Comparative performance of MRI-derived PRECISE scores and delta-radiomics models for the prediction of prostate cancer progression in patients on active surveillance

OBJECTIVES

To compare the performance of the PRECISE scoring system against several MRI-derived delta-radiomics models for predicting histopathological prostate cancer (PCa) progression in patients on active surveillance (AS).

METHODS

The study included AS patients with biopsy-proven PCa with a minimum follow-up of 2 years and at least one repeat targeted biopsy. Histopathological progression was defined as grade group progression from diagnostic biopsy. The control group included patients with both radiologically and histopathologically stable disease. PRECISE scores were applied prospectively by four uro-radiologists with 5-16 years' experience. T2WI- and ADC-derived delta-radiomics features were computed using baseline and latest available MRI scans, with the predictive modelling performed using the parenclitic networks (PN), least absolute shrinkage and selection operator (LASSO) logistic regression, and random forests (RF) algorithms. Standard measures of discrimination and areas under the ROC curve (AUCs) were calculated, with AUCs compared using DeLong's test.

RESULTS

The study included 64 patients (27 progressors and 37 non-progressors) with a median follow-up of 46 months. PRECISE scores had the highest specificity (94.7%) and positive predictive value (90.9%), whilst RF had the highest sensitivity (92.6%) and negative predictive value (92.6%) for predicting disease progression. The AUC for PRECISE (84.4%) was non-significantly higher than AUCs of 81.5%, 78.0%, and 80.9% for PN, LASSO regression, and RF, respectively (p = 0.64, 0.43, and 0.57, respectively). No significant differences were observed between AUCs of the three delta-radiomics models (p-value range 0.34-0.77).

CONCLUSIONS

PRECISE and delta-radiomics models achieved comparably good performance for predicting PCa progression in AS patients.

KEY POINTS

• The observed high specificity and PPV of PRECISE are complemented by the high sensitivity and NPV of delta-radiomics, suggesting a possible synergy between the two image assessment approaches. • The comparable performance of delta-radiomics to PRECISE scores applied by expert readers highlights the prospective use of the former as an objective and standardisable quantitative tool for MRI-guided AS follow-up. • The marginally superior performance of parenclitic networks compared to conventional machine learning algorithms warrants its further use in radiomics research.

Factors Associated with Time to Conversion from Active Surveillance to Treatment for Prostate Cancer in a Multi-Institutional Cohort

PURPOSE

We examined the demographic and clinicopathological parameters associated with the time to convert from active surveillance to treatment among men with prostate cancer.

MATERIALS AND METHODS

A multi-institutional cohort of 7,279 patients managed with active surveillance had data and biospecimens collected for germline genetic analyses.

RESULTS

Of 6,775 men included in the analysis, 2,260 (33.4%) converted to treatment at a median followup of 6.7 years. Earlier conversion was associated with higher Gleason grade groups (GG2 vs GG1 adjusted hazard ratio [aHR] 1.57, 95% CI 1.36-1.82; ≥GG3 vs GG1 aHR 1.77, 95% CI 1.29-2.43), serum prostate specific antigen concentrations (aHR per 5 ng/ml increment 1.18, 95% CI 1.11-1.25), tumor stages (cT2 vs cT1 aHR 1.58, 95% CI 1.41-1.77; ≥cT3 vs cT1 aHR 4.36, 95% CI 3.19-5.96) and number of cancerous biopsy cores (3 vs 1-2 cores aHR 1.59, 95% CI 1.37-1.84; ≥4 vs 1-2 cores aHR 3.29, 95% CI 2.94-3.69), and younger age (age continuous per 5-year increase aHR 0.96, 95% CI 0.93-0.99). Patients with high-volume GG1 tumors had a shorter interval to conversion than those with low-volume GG1 tumors and behaved like the higher-risk patients. We found no significant association between the time to conversion and self-reported race or genetic ancestry.

CONCLUSIONS

A shorter time to conversion from active surveillance to treatment was associated with higher-risk clinicopathological tumor features. Furthermore, patients with high-volume GG1 tumors behaved similarly to those with intermediate and high-risk tumors. An exploratory analysis of self-reported race and genetic ancestry revealed no association with the time to conversion.

MRI-derived radiomics model for baseline prediction of prostate cancer progression on active surveillance

Nearly half of patients with prostate cancer (PCa) harbour low- or intermediate-risk disease considered suitable for active surveillance (AS). However, up to 44% of patients discontinue AS within the first five years, highlighting the unmet clinical need for robust baseline risk-stratification tools that enable timely and accurate prediction of tumour progression. In this proof-of-concept study, we sought to investigate the added value of MRI-derived radiomic features to standard-of-care clinical parameters for improving baseline prediction of PCa progression in AS patients. Tumour T2-weighted imaging (T2WI) and apparent diffusion coefficient radiomic features were extracted, with rigorous calibration and pre-processing methods applied to select the most robust features for predictive modelling. Following leave-one-out cross-validation, the addition of T2WI-derived radiomic features to clinical variables alone improved the area under the ROC curve for predicting progression from 0.61 (95% confidence interval [CI] 0.481-0.743) to 0.75 (95% CI 0.64-0.86). These exploratory findings demonstrate the potential benefit of MRI-derived radiomics to add incremental benefit to clinical data only models in the baseline prediction of PCa progression on AS, paving the way for future multicentre studies validating the proposed model and evaluating its impact on clinical outcomes.

Active surveillance for prostate cancer

Many men diagnosed with localized prostate cancer can postpone definitive treatment without raising their risk of metastasis or death from disease. Active surveillance (AS) is a method of monitoring select men, with the option of switching to active treatment upon signs of progression, thereby avoiding the well-known side-effects of surgery and radiotherapy. This review analyzes the data from long-running AS cohorts to determine the safety and efficacy of AS. We conducted a narrative review of recently published data, including 14 articles from 13 AS cohorts. The cohorts used varying inclusion criteria, with reported differences in clinical T stage and Gleason Score (Grade Group), among other features. Some studies (n=5) limited their cohorts to low-risk patients, while others (n=8) also included intermediate-risk patients. The heterogeneity of the cohorts produced mixed results, with the risk of prostate cancer metastasis ranging from 0.1–1.0% at 10 years and the risk of prostate cancer mortality ranging from 0–1.9% at 10 years. However, the majority of studies reported risks of less than 0.5% at 10 years for both metastasis and death. For most cohorts, half of men remained untreated for 5–10 years, with estimates ranging from 37% receiving active treatment in the Toronto cohort to 73% in the Prostate Cancer Research International AS (PRIAS) study. Current data do not support the use of negative magnetic resonance imaging (MRI) to avoid scheduled biopsy. Taken together, the data collected from these AS cohorts suggests that AS is a safe approach for men with low-grade prostate cancer and some men with intermediate risk disease. AS should be more broadly implemented for eligible patients to avoid the decreases in quality of life from undergoing active treatment. Studies expanding the inclusion criteria and further defining a subset of men with favorable intermediate-risk prostate cancer who might safely benefit from AS are needed to assess the long-term outcomes of using AS in intermediate-risk groups.

The clinical impact of strict criteria for active surveillance of prostate cancer in Korean population: Results from a prospective cohort

Purpose

To evaluate the clinical impact of strict selection criteria for active surveillance (AS) of prostate cancer in a Korean population.

Materials and Methods

A single-center, prospectively collected AS cohort from December 2016 to February 2019 was used. Following pre-determined criteria, patients were categorized into “strict AS” and “non-strict AS” groups. Clinicopathological progression-free survival (PFS) and treatment-free survival (TFS) of the two groups were compared using the Kaplan–Meier curve and log-rank test. Age-adjusted hazard ratios for clinicopathological progression was calculated using Cox proportional regression analysis.

Results

Of 54 eligible patients, 25 and 29 were assigned to “strict AS” and “non-strict AS,” respectively. Clinicopathological progression and definitive treatment rates were 24.0% (6 of 25 patients) vs. 51.7% (15 of 29 patients) and 32.0% (8 of 25 patients) vs. 62.1% (18 of 29 patients) in “strict AS” and “non-strict AS” groups. Progress to high-risk cancer (pathologic T3 or surgical Gleason Grade 2 over) in radical prostatectomy was higher in “non-strict AS” than “strict AS”. PFS (mean 34.6±2.9 mo vs. 22.6±2.7 mo; p=0.025) and TFS (mean 31.8±3.2 mo vs. 19.6±2.4 mo; p=0.018) favor the “strict AS” group than “non-strict AS” group. Age-adjusted hazard ratio for clinicopathological progression of strict criteria was 0.36 (95% confidence interval, 0.14–0.94; p=0.04).

Conclusions

PFS and TFS were better in the “strict AS” group than in the “non-strict AS” group. This finding should be informed to relevant patients during decision making and considered in Korean guidelines.

What is the effect of MRI with targeted biopsies on the rate of patients discontinuing active surveillance? A reflection of the use of MRI in the PRIAS study

BACKGROUND

The reduction of overtreatment by active surveillance (AS) is limited in patients with low-risk prostate cancer (PCa) due to high rates of patients switching to radical treatment. MRI improves biopsy accuracy and could therewith affect inclusion in or continuation of AS. We aim to assess the effect of MRI with target biopsies on the total rate of patients discontinuing AS, and in particular discontinuation due to Grade Group (GG) reclassification.

METHODS

Three subpopulations included in the prospective PRIAS study with GG 1 were studied. Group A consists of patients diagnosed before 2009 without MRI before or during AS. Group B consists of patients diagnosed without MRI, but all patients underwent MRI within 6 months after diagnosis. Group C consists of patients who underwent MRI before diagnosis and during follow-up. We used cumulative incidence curves to estimate the rates of discontinuation.

RESULTS

In Group A (n = 500), the cumulative probability of discontinuing AS at 2 years is 27.5%; GG reclassification solely accounted for 6.9% of the discontinuation. In Group B (n = 351) these numbers are 30.9 and 22.8%, and for Group C (n = 435) 24.2 and 13.4%. The three groups were not randomized, however, baseline characteristics are highly comparable.

CONCLUSIONS

Performing an MRI before starting AS reduces the cumulative probability of discontinuing AS at 2 years. Performing an MRI after already being on AS increases the cumulative probability of discontinuing AS in comparison to not performing an MRI, especially because of an increase in GG reclassification. These results suggest that the use of MRI could lead to more patients being considered unsuitable for AS. Considering the excellent long-term cancer-specific survival of AS before the MRI era, the increased diagnostic accuracy of MRI could potentially lead to more overtreatment if definitions and treatment options of significant PCa are not adapted.