Active Surveillance for Prostate Cancer in a Real-life Cohort: Comparing Outcomes for PRIAS-eligible and PRIAS-ineligible Patients

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.

Value of machine learning-based transrectal multimodal ultrasound combined with PSA-related indicators in the diagnosis of clinically significant prostate cancer

Objective

To investigate the effect of transrectal multimodal ultrasound combined with serum prostate-specific antigen (PSA)-related indicators and machine learning for the diagnosis of clinically significant prostate cancer.

Methods

Based on Gleason score of postoperative pathological results, the subjects were divided into clinically significant prostate cancer groups(GS>6)and non-clinically significant prostate cancer groups(GS ≤ 6). The independent risk factors were obtained by univariate logistic analysis. Artificial neural network (ANN), logistic regression (LR), support vector machine (SVM), decision tree (DT), random forest (RF), and K-nearest neighbor (KNN) machine learning models were combined with clinically significant prostate cancer risk factors to establish the machine learning model, calculate the model evaluation indicators, construct the receiver operating characteristic curve (ROC), and calculate the area under the curve (AUC).

Results

Independent risk factor items (P< 0.05) were entered into the machine learning model. A comparison of the evaluation indicators of the model and the area under the ROC curve showed the ANN model to be best at predicting clinically significant prostate cancer, with a sensitivity of 80%, specificity of 88.6%, F1 score of 0.897, and the AUC was 0.855.

Conclusion

Establishing a machine learning model by rectal multimodal ultrasound and combining it with PSA-related indicators has definite application value in predicting clinically significant prostate cancer.

Active surveillance in renal transplant patients with prostate cancer: a multicentre analysis

INTRODUCTION

Due to medical improvements leading to increased life expectancy after renal transplantation and widened eligibility criteria allowing older patients to be transplanted, incidence of (low-risk) prostate cancer (PCa) is increasing among renal transplant recipients (RTR). It remains to be established whether active surveillance (AS) for PCa represents a safe treatment option in this setting. Therefore, we aim to compare AS discontinuation and oncological outcomes of AS for PCa of RTR vs. non-transplant patients.

METHODS

Multicentre study including RTR diagnosed with PCa between 2008 and 2018 in whom AS was initiated. A subgroup of non-RTR from the St. Antonius hospital AS cohort was used as a control group. Comparison of RTR vs. non-RTR was performed by 2:1 propensity score matched survival analysis. Outcome measures included tumour progression-free survival, treatment-free survival, metastasis rates, biochemical recurrence rates and overall survival. Patients were matched based on age, year of diagnosis, PSA, biopsy ISUP grade group, relative number of positive biopsy cores and clinical stage.

RESULTS

A total of 628 patients under AS were evaluated, including 17 RTRs and 611 non-RTRs. A total of 13 RTR cases were matched with 24 non-RTR cases. Median overall follow-up for the RTR and non-RTR matched cases was, respectively, 5.1 (IQR 3.2-8.7) years and 5.7 (IQR 4.8-8.1) years. There were no events of metastasis and biochemical recurrence among matched cases. The matched-pair analysis results in a 1-year and 5-year survival of the RTR and non-RTR patients were, respectively, 100 vs. 92%, and 39 vs. 76% for tumour progression, 100 vs. 91% and 59 vs. 76% for treatment-free survival and, respectively, 100 vs. 100% and 88 vs. 100% for overall survival. No significant differences in tumour progression-free survival (p = 0.07) and treatment-free survival were observed (p = 0.3). However, there was a significant difference in overall survival comparing both groups (p = 0.046).

CONCLUSIONS

AS may be carefully considered in RTR with low-risk PCa. In our preliminary analysis, no major differences were present in AS outcomes between RTR and non-RTR. Overall mortality was significantly higher in the RTR subgroup.

Knowledge, attitudes, and practices of active surveillance in prostate cancer among urologists: a real-life survey from Brazil

Background

Active surveillance (AS) is the preferred treatment for patients with very low-and low-risk prostate cancer (PCa), but it is underperformed worldwide. This study aimed to report knowledge, attitudes, and practices (KAP) of AS for PCa among urologists in Brazil.

Methods

This cross-sectional study used a questionnaire with 50 questions divided into participant characteristics, knowledge regarding inclusion criteria for AS, follow-up, intervention triggers, acceptance, and practice for an index patient. Data analysis comprises absolute and relative frequencies of the variables. After that, a logistic regression was performed in order to verify possible patterns of answers provided by the respondents in the index patient questionnaire.

Results

Questionnaires were sent through the SurveyMonkey® platform to 5,015 urologists using email addresses and through social media. A total of 600 (12%) questionnaires returned and 413 (8.2%) were completed and included in the analysis. Only 53% of urologists adopt AS for low- and very-low-risk PCa. Inclusion criteria were patients with age > 50 years (32.2%), prostate specific antigen (PSA) < 10 ng/mL (87.2%), T1 clinical stage (80.4%), Biopsy Gleason score ≤ 6, positive cores ≤ 2 (44.3%), positive core involvement < 50% (45.3%), and magnetic resonance imaging findings (38.7%). The PSA doubling time was still used by 60.3%. Confirmatory biopsy (55.9%), PSA level (36.6%), and digital rectal examination (34.4%) were considered by most urologists for follow-ups. Patient preference (85.7%), upgrade of Gleason score (73.4%), and increased number of positive cores (66.8%) were associated with conversion to definitive treatment. In an index patient, non-acceptance and active treatment request were the most cited reasons for not performing AS.

Conclusion

There is significant variability in the KAP of AS in Brazil, which indicates the need to reinforce AS, its inclusion and follow-up criteria, and the benefits for physicians and the general population.

Trial registration: Not applicable.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-022-01036-1.

Longitudinal evaluation of apparent diffusion coefficient values as a predictor of Prostate Cancer Research International Active Surveillance reclassification

PURPOSE

This study aimed to evaluate the effectiveness of apparent diffusion coefficient (ADC) parameters in distinguishing between Prostate Cancer Research International Active Surveillance (PRIAS) non-reclassification and reclassification groups during active surveillance (AS) of prostate cancer.

METHODS

We included 55 patients who fulfilled the PRIAS criteria and underwent ≥ 2 magnetic resonance imaging (MRI) including diffusion-weighted imaging with an interval of ≤ 3 years between baseline and second MRI. A mono-exponential fitting model was used to automatically create ADC maps with minimum b-values of 0 and maximum of 2000 s/mm². For detectable lesions on ADC maps, the lesions were manually segmented on each slice of the ADC maps. For undetectable lesions, the corresponding normal-appearing zone of the lobe on each slice of ADC maps was segmented. The ADC data for each slice were summed to obtain the 25th, 50th, and 75th percentile ADC values of the histogram at baseline and second MRI. These ADC parameters at baseline and second MRI, and the changes of ADC parameters from baseline to second MRI were compared between PRIAS non-reclassification and reclassification groups.

RESULTS

The PRIAS reclassification group had significantly lower 25th, 50th, and 75th percentile ADC values at second MRI compared to the non-reclassification group. The non-reclassification group had significantly lower changes in ADC values in these percentiles compared to the reclassification group.

CONCLUSION

The ADC parameters at second MRI and the changes from baseline to second MRI may be effective distinguishing factors between PRIAS non-reclassification and reclassification groups.

Systematic Review of Active Surveillance for Clinically Localised Prostate Cancer to Develop Recommendations Regarding Inclusion of Intermediate-risk Disease, Biopsy Characteristics at Inclusion and Monitoring, and Surveillance Repeat Biopsy Strategy

CONTEXT

There is uncertainty regarding the most appropriate criteria for recruitment, monitoring, and reclassification in active surveillance (AS) protocols for localised prostate cancer (PCa).

OBJECTIVE

To perform a qualitative systematic review (SR) to issue recommendations regarding inclusion of intermediate-risk disease, biopsy characteristics at inclusion and monitoring, and repeat biopsy strategy.

EVIDENCE ACQUISITION

A protocol-driven, Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA)-adhering SR incorporating AS protocols published from January 1990 to October 2020 was performed. The main outcomes were criteria for inclusion of intermediate-risk disease, monitoring, reclassification, and repeat biopsy strategies (per protocol and/or triggered). Clinical effectiveness data were not assessed.

EVIDENCE SYNTHESIS

Of the 17 011 articles identified, 333 studies incorporating 375 AS protocols, recruiting 264 852 patients, were included. Only a minority of protocols included the use of magnetic resonance imaging (MRI) for recruitment (n = 17), follow-up (n = 47), and reclassification (n = 26). More than 50% of protocols included patients with intermediate or high-risk disease, whilst 44.1% of protocols excluded low-risk patients with more than three positive cores, and 39% of protocols excluded patients with core involvement (CI) >50% per core. Of the protocols, ≥80% mandated a confirmatory transrectal ultrasound biopsy; 72% (n = 189) of protocols mandated per-protocol repeat biopsies, with 20% performing this annually and 25% every 2 yr. Only 27 protocols (10.3%) mandated triggered biopsies, with 74% of these protocols defining progression or changes on MRI as triggers for repeat biopsy.

CONCLUSIONS

For AS protocols in which the use of MRI is not mandatory or absent, we recommend the following: (1) AS can be considered in patients with low-volume International Society of Urological Pathology (ISUP) grade 2 (three or fewer positive cores and cancer involvement ≤50% CI per core) or another single element of intermediate-risk disease, and patients with ISUP 3 should be excluded; (2) per-protocol confirmatory prostate biopsies should be performed within 2 yr, and per-protocol surveillance repeat biopsies should be performed at least once every 3 yr for the first 10 yr; and (3) for patients with low-volume, low-risk disease at recruitment, if repeat systematic biopsies reveal more than three positive cores or maximum CI >50% per core, they should be monitored closely for evidence of adverse features (eg, upgrading); patients with ISUP 2 disease with increased core positivity and/or CI to similar thresholds should be reclassified.

PATIENT SUMMARY

We examined the literature to issue new recommendations on active surveillance (AS) for managing localised prostate cancer. The recommendations include setting criteria for including men with more aggressive disease (intermediate-risk disease), setting thresholds for close monitoring of men with low-risk but more extensive disease, and determining when to perform repeat biopsies (within 2 yr and 3 yearly thereafter).

Long-term Outcomes of Focal Cryotherapy for Low- to Intermediate-risk Prostate Cancer: Results and Matched Pair Analysis with Active Surveillance

BACKGROUND

To date, only one trial compared focal therapy and active surveillance (AS) for low-risk prostate cancer (PCa). In addition, long-term outcomes of focal cryotherapy (FC) are lacking.

OBJECTIVE

Our aim was to evaluate long-term outcomes of FC and compare them with AS.

DESIGN, SETTING, AND PARTICIPANTS

We included two prospective series of 121 (FC) and 459 (AS) consecutive patients (2008-2018) for low- to intermediate-risk PCa.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Study outcomes were radical therapy-free or androgen deprivation therapy (ADT)-free, any treatment-free, metastasis-free, and overall survival. A matched pair analysis was performed using seven covariates.

RESULTS AND LIMITATIONS

The median FC follow-up was 85 mo (interquartile range 58-104); 92 (76%) men had International Society of Urological Pathology (ISUP) grade 1. Among matched variables, no significant differences were present except for cT stage and year of entry (both p < 0.01). Ten-year radical therapy-free or ADT-free, any treatment-free, metastasis-free, and overall survival were 51%, 40.2%, 93.9%, and 97%, respectively for FC. No differences were noted with AS (all p > 0.05), with the exception of time to radical therapy, time to radical therapy and ADT, and time to any treatment, all being shorter for AS (all p < 0.01). Freedom from radical treatment or ADT was higher for FC (AS 10 yr 39.3%; p = 0.04). Complications were relatively rare (26.5%) and mainly of low grade (Clavien >2, n = 3); three men developed incontinence (p = 0.0814), while both International Index of Erectile Function 5 and International Prostate Symptom Score scores increased (p = 0.0287 and p = 0.0165, respectively). Limitations include absence of randomization.

CONCLUSIONS

At an early long-term follow-up, FC in the context of mainly low-risk PCa is safe and increases time to radical therapy but does not provide meaningful oncological advantages compared with AS.

PATIENT SUMMARY

We compared focal cryotherapy with active surveillance mainly for low-risk prostate cancer. Focal cryotherapy, despite having fewer complications, did not yield meaningful advantages over active surveillance at 10 yr. Active surveillance should be preferred to focal cryotherapy for these patients.

[Active surveillance of prostate cancer: treatement-free survival according to restricted or expanded eligibility criteria]

AIM

Overtreatment is an actual problem in low risk localized prostate cancer (PC) management. Active surveillance (AS) is a solution to limit this problem, but eligibility criteria remained discussed. The aim was to assess possibilities of widening selection criteria for patient in AS, studying curative treatment free survival (CTFS) according to restricted or expanded eligibility criteria.

METHODS

We retrospectively studied patients beginning AS between 2008 and 2014, for Gleason 6 localized PC, PSA<15ng/ml,<cT3. The group "strict criteria" was defined:≤cT2a, PSA<10ng/ml, 2≤positive biopsies (PB+), total tumoral length≤3mm, tumoral invading≤50%, PSA density≤0,15ng/ml/cm³. MRI was performed at baseline and during follow-up. Radical treatment was proposed in case of biological, histological or clinical progression. Criteria associated with AS survival were analyzed by Cox regression.

RESULTS

One hundred eighty patients were included (follow-up 46 months). One hundred and eleven patients had "strict" criteria vs. 69 "expanded" criteria. Eighty-two patients (45%) were treated with median time of 18.2 months (CTFS was 71% at 2 years, 52% at 5 years.). The widening of the inclusion criteria was not associated with CTFS (65 vs 54% at 5 years, P=0.13). Factors significatively associated with discontinuation of AS were bilaterality (HR=2.12) and abnormal rectal digital examination cT2 (HR=2,07); MRI target (HR=2,48)) tended towards significance.

CONCLUSION

Our study concludes that curative treatment free survival is similar for patients included with expanded criteria compared with those included with strict criteria. However, high initial cancer volume) is associated with AS discontinuation.

LEVEL OF EVIDENCE

3.