Active Surveillance-Is It Feasible for Intermediate-risk Localised Prostate Cancer?

Comparison of Outcomes of Active Surveillance in Intermediate-Risk Versus Low-Risk Localised Prostate Cancer Patients: A Systematic Review and Meta-Analysis

Currently, there is no clear consensus regarding the role of active surveillance (AS) in the management of intermediate-risk prostate cancer (IRPC) patients. We aim to analyse data from the available literature on the outcomes of AS in the management of IRPC patients and compare them with low-risk prostate cancer (LRPC) patients. A comprehensive literature search was performed, and relevant data were extracted. Our primary outcome was treatment-free survival, and secondary outcomes were metastasis-free survival, cancer-specific survival, and overall survival. The DerSimonian–Laird random-effects method was used for the meta-analysis. Out of 712 studies identified following an initial search, 25 studies were included in the systematic review. We found that both IRPC and LRPC patients had nearly similar 5, 10, and 15 year treatment-free survival rate, 5 and 10 year metastasis-free survival rate, and 5 year overall survival rate. However, cancer-specific survival rates at 5, 10, and 15 years were significantly lower in IRPC compared to LRPC group. Furthermore, IRPC patients had significantly inferior long-term overall survival rate (10 and 15 year) and metastasis-free survival rate (15 year) compared to LRPC patients. Both the clinicians and the patients can consider this information during the informed decision-making process before choosing AS.

Expanding inclusion criteria for active surveillance in intermediate-risk prostate cancer: a machine learning approach

PURPOSE

To develop new selection criteria for active surveillance (AS) in intermediate-risk (IR) prostate cancer (PCa) patients.

METHODS

Retrospective study including patients from 14 referral centers who underwent pre-biopsy mpMRI, image-guided biopsies and radical prostatectomy. The cohort included biopsy-naive IR PCa patients who met the following inclusion criteria: Gleason Grade Group (GGG) 1-2, PSA < 20 ng/mL, and cT1-cT2 tumors. We relied on a recursive machine learning partitioning algorithm developed to predict adverse pathological features (i.e., ≥ pT3a and/or pN + and/or GGG ≥ 3).

RESULTS

A total of 594 patients with IR PCa were included, of whom 220 (37%) had adverse features. PI-RADS score (weight:0.726), PSA density (weight:0.158), and clinical T stage (weight:0.116) were selected as the most informative risk factors to classify patients according to their risk of adverse features, leading to the creation of five risk clusters. The adverse feature rates for cluster #1 (PI-RADS ≤ 3 and PSA density < 0.15), cluster #2 (PI-RADS 4 and PSA density < 0.15), cluster #3 (PI-RADS 1-4 and PSA density ≥ 0.15), cluster #4 (normal DRE and PI-RADS 5), and cluster #5 (abnormal DRE and PI-RADS 5) were 11.8, 27.9, 37.3, 42.7, and 65.1%, respectively. Compared with the current inclusion criteria, extending the AS criteria to clusters #1 + #2 or #1 + #2 + #3 would increase the number of eligible patients (+ 60 and + 253%, respectively) without increasing the risk of adverse pathological features.

CONCLUSIONS

The newly developed model has the potential to expand the number of patients eligible for AS without compromising oncologic outcomes. Prospective validation is warranted.

Prospective Implementation and Early Outcomes of a Risk-stratified Prostate Cancer Active Surveillance Follow-up Protocol

Background

Active surveillance (AS) is a major management option for men with early prostate cancer. Current guidelines however advocate identical AS follow-up for all without considering different disease trajectories. We previously proposed a pragmatic three-tier STRATified CANcer Surveillance (STRATCANS) follow-up strategy based on different progression risks from clinic-pathological and imaging features.

Objective

To report early outcomes from the implementation of the STRATCANS protocol in our centre.

Design setting and participants

Men on AS were enrolled into a prospective stratified follow-up programme.

Intervention

Three tiers of increasing follow-up intensity based on National Institute for Health and Care Excellence (NICE): Cambridge Prognostic Group (CPG) 1 or 2, prostate-specific antigen density, and magnetic resonance imaging (MRI) Likert score at entry.

Outcome measurements and statistical analysis

Rates of progression to CPG ≥3, any pathological progression, AS attrition, and patient choice for treatment were assessed. Differences in progression were compared with chi-square statistics.

Results and limitations

Data from 156 men (median age 67.3 yr) were analysed. Of these, 38.4% had CPG2 disease and 27.5% had grade group 2 disease at diagnosis. The median time on AS was 4 yr (interquartile range 3.2-4.9) and 1.5 yr on STRATCANS. Overall, 135/156 (86.5%) men remained on AS or converted to watchful waiting and 6/156 (3.8%) stopped AS by choice by the end of the evaluation period. Of the 156 patients, 66 (42.3%) were allocated to STRATCANS 1 (least intense follow-up), 61 (39.1%) to STRATCANS 2, and 29 (18.6%) to STRATCANS 3 (highest intensity). By increasing STRATCANS tier, progression rates to CPG ≥3 and any progression events were 0% and 4.6%, 3.4% and 8.6%, and 7.4% and 22.2%, respectively (p = 0.019). Modelling resource usage suggested potential reductions in appointments by 22% and MRI by 42% compared with current NICE guideline recommendations (first 12 months of AS). The study is limited by short follow-up, a relatively small cohort, and being single centre.

Conclusions

A simple risk-tiered AS strategy is possible with early outcomes supporting stratified follow-up intensity. STRATCANS implementation could de-escalate follow-up in men at a low risk of progression while husbanding resources for those who need closer follow-up.

Patient summary

We report a practical way to personalise follow-up for men on active surveillance for early prostate cancer. Our method may allow reductions in the follow-up burden for men at a low risk of disease change while maintaining vigilance for those at a higher risk.

Active Surveillance for Intermediate-risk Prostate Cancer: A Systematic Review, Meta-analysis, and Metaregression

CONTEXT

Active surveillance (AS) is increasingly selected among patients with localized, intermediate-risk (IR) prostate cancer (PCa). However, the safety and optimal candidate selection for those with IR PCa remain uncertain.

OBJECTIVE

To evaluate treatment-free survival and oncologic outcomes in patients with IR PCa managed with AS and to compare with AS outcomes in low-risk (LR) PCa patients.

EVIDENCE ACQUISITION

A literature search was conducted through February 2022 using PubMed/Medline, Embase, and Web of Science databases. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed to identify eligible studies. The coprimary outcomes were treatment-free, metastasis-free, cancer-specific, and overall survival. A subgroup analysis was planned a priori to explore AS outcomes when limiting inclusion to IR patients with a Gleason grade (GG) of ≤2.

EVIDENCE SYNTHESIS

A total of 25 studies including 29 673 unselected IR patients met our inclusion criteria. The 10-yr treatment-free, metastasis-free, cancer-specific, and overall survival ranged from 19.4% to 69%, 80.8% to 99%, 88.2% to 99%, and 59.4% to 83.9%, respectively. IR patients had similar treatment-free survival to LR patients (risk ratio [RR] 1.16, 95% confidence interval (CI), 0.99-1.36, p = 0.07), but significantly higher risks of metastasis (RR 5.79, 95% CI, 4.61-7.29, p < 0.001), death from PCa (RR 3.93, 95% CI, 2.93-5.27, p < 0.001), and all-cause death (RR 1.44, 95% CI, 1.11-1.86, p = 0.005). In a subgroup analysis of studies including patients with GG ≤2 only (n = 4), treatment-free survival (RR 1.03, 95% CI, 0.62-1.71, p = 0.91) and metastasis-free survival (RR 2.09, 95% CI, 0.75-5.82, p = 0.16) were similar between LR and IR patients. Treatment-free survival was significantly reduced in subgroups of patients with unfavorable IR disease and increased cancer length on biopsy.

CONCLUSIONS

The present systematic review and meta-analysis highlight the need to optimize patient selection for those with IR features. Our findings support limiting the inclusion of IR patients in AS to those with low-volume GG 2 tumor.

PATIENT SUMMARY

Active surveillance is increasingly used in patients with localized, intermediate-risk (IR) prostate cancer. In this population, we have reported higher risks of metastasis and cancer mortality in unselected patients than in patients with low-risk features, underscoring the need to optimize the selection of patients with IR features.