Guidelines of guidelines: focal therapy for prostate cancer, is it time for consensus?

MR-guided Focused Ultrasound Focal Therapy for Prostate Cancer

Prostate cancer (PCa) is a prevalent malignancy in men, and the management of localized disease has evolved significantly in recent years. Focal therapy, wherein the biopsy confirmed site of tumor with margins is treated leaving the remaining gland intact, has emerged as a promising strategy for treating localized clinically significant PCa, minimizing side effects associated with radical therapies. We present the technical aspects, a summary of the most relevant evidence to date on the performance and safety of this technique, and the characteristic MR imaging findings during treatment, in the early posttreatment period and in the long term.

Extracapsular extension risk assessment using an artificial intelligence prostate cancer mapping algorithm

Objective

The objective of this study is to compare detection rates of extracapsular extension (ECE) of prostate cancer (PCa) using artificial intelligence (AI)-generated cancer maps versus MRI and conventional nomograms.

Materials and methods

We retrospectively analysed data from 147 patients who received MRI-targeted biopsy and subsequent radical prostatectomy between September 2016 and May 2022. AI-based software cleared by the United States Food and Drug Administration (Unfold AI, Avenda Health) was used to map 3D cancer probability and estimate ECE risk. Conventional ECE predictors including MRI Likert scores, capsular contact length of MRI-visible lesions, PSMA T stage, Partin tables, and the "PRedicting ExtraCapsular Extension" nomogram were used for comparison.Postsurgical specimens were processed using whole-mount histopathology sectioning, and a genitourinary pathologist assessed each quadrant for ECE presence. ECE predictors were then evaluated on the patient (Unfold AI versus all comparators) and quadrant level (Unfold AI versus MRI Likert score). Receiver operator characteristic curves were generated and compared using DeLong's test.

Results

Unfold AI had a significantly higher area under the curve (AUC = 0.81) than other predictors for patient-level ECE prediction. Unfold AI achieved 68% sensitivity, 78% specificity, 71% positive predictive value, and 75% negative predictive value. At the quadrant level, Unfold AI exceeded the AUC of MRI Likert scores for posterior (0.89 versus 0.82, p = 0.003), anterior (0.84 versus 0.80, p = 0.34), and all quadrants (0.89 versus 0.82, p = 0.002). The false negative rate of Unfold AI was lower than MRI in both the anterior (-60%) and posterior prostate (-40%).

Conclusions

Unfold AI accurately predicted ECE risk, outperforming conventional methodologies. It notably improved ECE prediction over MRI in posterior quadrants, with the potential to inform nerve-spare technique and prevent positive margins. By enhancing PCa staging and risk stratification, AI-based cancer mapping may lead to better oncological and functional outcomes for patients.

Biopsy strategies in the era of mpMRI: a comprehensive review

BACKGROUND

Since its initial description the prostate biopsy technique for detection of prostate cancer (PCA) has constantly evolved. Multiparametric magnetic resonance imaging (mpMRI) has been proven to have a sensitivity exceeding 90% to detect the index lesion. This narrative review discusses the evidence around several biopsy strategies, especially in the context of patients that might be eligible for focal therapy.

METHOD

A non-systematic literature research was performed on February 15th 2024 using the Medical Literature Analysis and Retrieval System Online (Medline), Web of Science and Google Scholar.

RESULTS

The transrectal (TR) route is associated with an increased postoperative sepsis rate, even with adequate antibiotic prophylaxis. The transperineal (TP) route is now recommended by international guidelines, firstly for its decreased rate of urosepsis. Recent evidence shows a non-inferiority of TP compared to TR route, and even a higher detection rate of clinically significant PCA (csPCA) in the anterior and apical region, that are usually difficult to target using the TR route. Several targeting techniques (cognitive, software-fusion or in-bore) enhance our ability to provide an accurate risk assessment of prostate cancer aggressiveness and burden, while reducing the number of cores and reducing the number of clinically insignificant prostate cancer (ciPCA). While MRI-TB have proven their role, the role of systematic biopsies (SB) is still important because it detects 5-16% of csPCA that would have been missed by MRI-TB alone. The strategies of SB depend mainly on the route used (TR vs. TP) and the number of cores to be collected (10-12 cores vs. saturation biopsies vs. trans-perineal template mapping-biopsies or Ginsburg Protocol vs. regional biopsies).

CONCLUSION

Several biopsy strategies have been described and should be known when assessing patients for focal therapy. Because MRI systematically under evaluates the lesion size, systematic biopsies, and especially perilesional biopsies, can help to increase sensitivity at the cost of an increased number of cores.

Irreversible electroporation of localised prostate cancer downregulates immune suppression and induces systemic anti-tumour T-cell activation - IRE-IMMUNO study

OBJECTIVES

To prospectively compare systemic anti-tumour immune responses induced by irreversible electroporation (IRE) and robot-assisted radical prostatectomy (RARP) in patients with localised intermediate-risk prostate cancer (PCa).

PATIENTS AND METHODS

Between February 2021 and June 2022, before and after treatment (at 5, 14 and 30 days) peripheral blood samples of 30 patients with localised PCa were prospectively collected. Patient inclusion criteria were: International Society of Urological Pathologists Grade 2-3, clinical cancer stage ≤T2c, prostate-specific antigen level <20 ng/mL). Patients were treated with IRE (n = 20) or RARP (n = 10). Frequency and activation status of lymphocytic and myeloid immune cell subsets were determined using flow cytometry. PCa-specific T-cell responses to prostatic acid phosphatase (PSAP) and cancer testis antigen (New York oesophageal squamous cell carcinoma 1 [NY-ESO-1]) were determined by interferon-γ enzyme-linked immunospot assay (ELISpot). Repeated-measures analysis of variance and two-sided Student's t-tests were used to compare immune responses over time and between treatment cohorts.

RESULTS

Patient and tumour characteristics were similar between the cohorts except for age (median 68 years [IRE] and 62 years [RARP], P = 0.01). IRE induced depletion of systemic regulatory T cells (P = 0.0001) and a simultaneous increase in activated cytotoxic T-lymphocyte antigen 4 (CTLA-4)+ cluster of differentiation (CD)4+ (P < 0.001) and CD8+ (P = 0.032) T cells, consistent with reduction of systemic immune suppression allowing for effector T-cell activation, peaking 14 days after IRE. Effects were positively correlated with tumour volume/ablation size. Accordingly, IRE induced expansion of PSAP and/or NY-ESO-1 specific T-cell responses in four of the eight immune competent patients. Temporarily increased activated myeloid derived suppressor cell frequencies (P = 0.047) were consistent with transient immunosuppression after RARP.

CONCLUSIONS

Irreversible electroporation induces a PCa-specific systemic immune response in patients with localised PCa, aiding conversion of the tumour microenvironment into a more immune permissive state. Therapeutic efficacy might be further enhanced by combination with CTLA-4 checkpoint inhibition, potentially opening up a new synergistic treatment paradigm for high-risk localised or (oligo)metastatic disease.

Targeted microwave ablation for prostate cancer (FOSTINE1b): a prospective 'ablate-and-resect' study

OBJECTIVE

To assess histopathological outcomes, as well as feasibility and safety of targeted microwave ablation (TMA) via the Trinity® system (KOELIS, La Tronche, France).

PATIENTS AND METHODS

Prospective, single-institution, interventional Phase IIa study with an 'ablate-and-resect' design. In all, 11 patients diagnosed with localised prostate cancer (PCa) underwent TMA via the Trinity system under conscious sedation in an outpatient setting using a single transrectal TATO® 18-G antenna with different treatment regimens. Magnetic resonance imaging (MRI) and robot-assisted radical prostatectomy (RARP) were conducted at 7 days and 1 month after TMA, respectively. Nine patients received RARP, and two patients chose to withdraw their consent following TMA. These men chose an active surveillance protocol upon confirmation of a low-risk prostate cancer diagnosis. Functional outcomes and adverse events were evaluated at baseline and follow-up visits using validated questionnaires. Prostate volumetry and confirmation of necrosis were carried out through MRI and whole-mount histopathological examination.

RESULTS

The TMA was successfully executed, and all patients were discharged on the same day. No severe adverse events (Common Terminology Criteria for Adverse Events Grade ≥3) were reported at the 7-day and 1-month follow-up visits. Additionally, no declines were observed in urinary, sexual and ejaculation functional outcomes. T1-weighted MRI revealed clear and well-defined ablation zones. The RARP was executed without difficulty, particularly during the dissection of the posterior plane. As a result, no intraoperative complications were encountered. Histopathological assessment on surgical specimens confirmed the absence of viable cells, indicating complete necrosis of the ablative zone if a power intensity >10 W was used during TMA. Ablation zone volumetry revealed no notable distinctions between the three-dimensional segmentation of the virtual ablation zone at TMA (median volume: 2 mL) and MRI (median volume: 1.923 mL). Conversely, a significant reduction was noted in the surgical specimen (median volume: 0.221 mL).

CONCLUSIONS

Targeted microwave ablation via the Trinity system for localised PCa treatment proves to be a secure and feasible procedure, with complete necrosis evidence within the ablation zone on surgical specimens.

A Description and Safety Overview of Irreversible Electroporation for Prostate Tissue Ablation in Intermediate-Risk Prostate Cancer Patients: Preliminary Results from the PRESERVE Trial

The PRESERVE study (NCT04972097) aims to evaluate the safety and effectiveness of the NanoKnife System to ablate prostate tissue in patients with intermediate-risk prostate cancer (PCa). The NanoKnife uses irreversible electroporation (IRE) to deliver high-voltage electrical pulses to change the permeability of cell membranes, leading to cell death. A total of 121 subjects with organ-confined PCa ≤ T2c, prostate-specific antigens (PSAs) ≤ 15 ng/mL, and a Gleason score of 3 + 4 or 4 + 3 underwent focal ablation of the index lesion. The primary endpoints included negative in-field biopsy and adverse event incidence, type, and severity through 12 months. At the time of analysis, the trial had completed accrual with preliminary follow-up available. Demographics, disease characteristics, procedural details, PSA responses, and adverse events (AEs) are presented. The median (IQR) age at screening was 67.0 (61.0-72.0) years and Gleason distribution 3 + 4 (80.2%) and 4 + 3 (19.8%). At 6 months, all patients with available data (n = 74) experienced a median (IQR) percent reduction in PSA of 67.6% (52.3-82.2%). Only ten subjects (8.3%) experienced a Grade 3 adverse event; five were procedure-related. No Grade ≥ 4 AEs were reported. This study supports prior findings that IRE prostate ablation with the NanoKnife System can be performed safely. Final results are required to fully assess oncological, functional, and safety outcomes.

Bibliometric analysis of focal therapy in prostate cancer research

Introduction

The use of focal therapies for prostate cancer (PCa) has soared, as it controls disease and is associated with minimal side effects. Bibliometric analysis examines the global research landscape on any topic to identify gaps in the research and areas for improvement and prioritize future research efforts. This study aims to examine the research outputs and trends and collaboration landscape in the field of focal therapy for PCa on a global scale.

Methods

We searched Medline, PubMed and Scopus for peer-reviewed publications on our research topic using controlled keywords. Search results were limited to the period between 1980 and 2022, screened for duplicates and then included in our study based on prespecified eligibility criteria. The Bibliometrix Package was used for comprehensive science mapping analysis of co-authorship, co-citation and co-occurrence analysis of countries, institutions, authors, references and keywords in this field.

Results

This analysis included 2578 research articles. The annual scientific production increased from one article in 1982 to 143 in 2022 (13.21%). The average citation per year was incrementally increasing, and these documents were cited around 32.52 times. The documents included in this analysis were published in 633 sources. The international collaboration index was 22.7. In total, 6280 author keywords were identified. The most used keywords were 'prostate cancer', 'focal therapy', 'prostate' and 'photodynamic therapy'.

Conclusion

This bibliometric analysis has provided a comprehensive review of focal therapy in PCa research, highlighting both the significant growth in the field and the existing gaps that require further exploration. The study points to the need for more diverse international collaboration and exploration of various treatment modalities within the context of focal therapy.

Survival benefit of radical prostatectomy in patients with advanced TURP-diagnosed prostate cancer: a population-based real-world study

OBJECTIVES

A considerable number of patients are diagnosed with prostate cancer (PCa) by transurethral resection of the prostate (TURP). We aimed to evaluate whether radical prostatectomy (RP) brings survival benefits for these patients, especially in the elderly with advanced PCa.

PATIENTS AND METHODS

We used the Surveillance, Epidemiology, and End Results (SEER) database to obtain PCa cases diagnosed with TURP. After the propensity matching score (PSM) for case matching, univariate, multivariate, and subgroup analyses were performed to investigate whether RP impacts the survival benefit.

RESULTS

4,677 cases diagnosed with PCa by TURP from 2010 to 2019 were obtained, including 1,313 RP patients and 3,364 patients with no RP (nRP). 9.6% of RP patients had advanced PCa. With or without PSM, cancer-specific mortality (CSM) and overall mortality (OM) were significantly reduced in the RP patients compared to the nRP patients, even for older (> 75 ys.) patients with advanced stages (all p < 0.05). Except for RP, younger age (≤ 75 ys.), being married, and earlier stage (localized) contributed to a significant reduction of CSM risk (all p < 0.05). These survival benefits had no significant differences among patients of different ages, married or single, and at different stages (all p for interaction > 0.05).

CONCLUSIONS

Based on this retrospective population-matched study, we first found that in patients diagnosed with PCa by TURP, RP treatment may lead to a survival benefit, especially a reduction in CSM, even in old aged patients (> 75 ys.) with advanced PCa.

MRI-based monitoring of prostate cancer after HIFU: Inter-reader agreement and diagnostic performance of the PI-FAB score

PURPOSE

To investigate inter-reader agreement, and diagnostic performance of the Prostate Imaging after Focal Ablation (PI-FAB) score applied to multiparametric MRI (mpMRI) in patients who underwent focal high-intensity focused ultrasound (HIFU) therapy for localized prostate cancer.

METHODS

In this retrospective, IRB-approved, single-center study, 73 men, who underwent focal HIFU treatment and received follow-up mpMRIs with subsequent prostate biopsies, were included. The PI-FAB score was applied to follow-up MRIs at 6, 12, and 36 months post-HIFU by two radiologists with different experience levels. Inter-reader agreement was assessed using Gwet's AC1, and the diagnostic performance of the PI-FAB score was assessed in relation to histopathologic results of subsequent prostate biopsies for each reader.

RESULTS

PI-FAB scores showed substantial to almost perfect inter-reader agreement (AC1: 0.80-0.95) and demonstrated high specificity (Reader 1: 90-98 %, Reader 2: 87-98 %) and NPVs (Reader 1: 91-100 %, Reader 2: 88-97 %) in ruling out residual or recurrent in-field prostate cancer post-HIFU. Sensitivity (Reader 1: ≥43 %, Reader 2: ≥14 %) and PPVs (Reader 1: ≥33 %, Reader 2: ≥14 %) were mostly relatively lower, with notable disparities between the two readers, indicating the potential influence of radiologist experience.

CONCLUSIONS

The PI-FAB score provides a consistent and reliable tool for post-HIFU monitoring of prostate cancer using mpMRI. It demonstrates substantial to almost perfect inter-reader agreement and is particularly effective in excluding in-field residual or recurrent prostate cancer post-HIFU treatment. Its application can potentially enhance post-treatment patient care, emphasizing its value as a non-invasive MRI-based monitoring approach after focal ablative therapy of the prostate.

Long-term Outcomes and Patient Satisfaction Following Salvage Robot-assisted Radical Prostatectomy: A Modern Perspective

Background and objective

Approximately two-thirds of men who undergo primary treatment for prostate cancer (PC) will experience biochemical recurrence (BCR). Salvage robot-assisted radical prostatectomy (sRARP) offers curative treatment in this disease setting and men who choose this option may avoid palliative androgen deprivation therapy (ADT). The purpose of this study was to describe long-term outcomes and patient feedback following sRARP.

Methods

We reviewed data for consecutive men with biopsy-proven localized BCR who underwent sRARP and pelvic lymph node dissection at a single tertiary referral center between 2004 and 2021. Perioperative data, Clavien-Dindo complications, and functional outcomes were recorded. The Kaplan-Meier method was used to estimate prostate-specific antigen-free (≥0.2 ng/ml) survival (PSAFS) and metastasis-free survival (MFS). Three Likert-type items (score 1-5) from the validated Surgical Satisfaction Questionnaire-8 were distributed to patients postoperatively.

Key findings and limitations

We included 78 men, of whom 72 (92%) had undergone primary radiotherapy and six (8%) had received primary prostate ablation. Median follow-up was 10.1 yr (interquartile range 5.8-12.4). Final pathology identified ≥pT3N0M0 in 35 patients (45%) and positive margins in 23 (29%). The overall complication rate was 50%. Of the 26 (33%) major (grade ≥III) complications, anastomotic stricture (32%) was most common. The estimated 3-, 5-, and 10-yr survival rates were 85.6% and 80.2%, 83.5% for PSAFS (n = 11), and 74.1%, 83.5%, and 70.5% for MFS (n = 23), respectively. At last follow-up, postoperative ADT had been administered to 17 patients (22%), and 39 men (50%) remained alive a decade after sRARP. Continence and potency were maintained in 33/62 (53%) and 1/16 (6%) patients, respectively. Thirty-five respondents (45%) reported median questionnaire scores (≥4) in favor of sRARP. Limitations include the small single-center series and a single query point for patient feedback.

Conclusions and clinical implications

Long-term outcomes of sRARP suggest that the technical challenges and morbidity of the procedure are qualified by patient feedback and the opportunity to evade the morbidity and mortality of biochemically recurrent PC.

Patient summary

We reviewed the cancer outcomes and side effects of robot-assisted surgical removal of the prostate after treatment failure with radiation or ablation for prostate cancer. We found that this type of treatment has substantial risks and long-term side effects, but the surgery provides an opportunity to cure prostate cancer and/or avoid the consequences of indefinite hormonal treatment. Overall, most men who underwent this surgery were not disappointed with their decision despite the higher risks and consequences.

Cryotherapy for partial gland ablation of prostate cancer: Oncologic and safety outcomes

BACKGROUND

Partial gland ablation (PGA) is a new option for treatment of prostate cancer (PCa). Cryotherapy, an early method of PGA, has had favorable evaluations, but few studies have employed a strict protocol using biopsy endpoints in men with clinically significant prostate cancer (csPCa).

METHODS

143 men with unilateral csPCa were enrolled in a prospective, observational trial of outpatient PGA-cryotherapy. Treatment was a 2-cycle freeze of the affected prostate part. Participants were evaluated with MRI-guided biopsy (MRGB) at baseline and at 6 months and 18 months after treatment. Absence of csPCa upon MRGB was the primary endpoint; quality-of-life at baseline and at 6 months after treatment was assessed by EPIC-CP questionnaires in the domains of urinary and sexual function.

RESULTS

Of the 143 participants, 136 (95%) completed MRGB at 6 months after treatment. In 103/136 (76%), the biopsy revealed no csPCa. Of the 103, 71 subsequently had an 18-month comprehensive biopsy; of the 71 with 18-month biopsies, 46 (65%) were found to have no csPCa. MRI lesions became undetectable in 96/130 (74%); declines in median serum PSA levels (6.9 to 2.5 ng/mL), PSA density (0.15 to 0.07), and prostate volume (42 to 34cc) were observed (all p < 0.01). Neither lesion disappearance on MRI nor PSA decline correlated with biopsy outcome. Urinary function was affected only slightly and sexual function moderately.

CONCLUSION

In the near to intermediate term, partial gland ablation with cryotherapy was found to be a safe and moderately effective treatment of intermediate-risk prostate cancer. Eradication of cancer was better determined by MRI-guided biopsy than by MRI or PSA.

Risk Factors for Severe Erectile Dysfunction after Focal Therapy with High-Intensity Focused Ultrasound for Prostate Cancer

The present study aimed to analyze the effect of predisposing clinical factors for severe erectile dysfunction (ED) in patients treated with focal therapy using high-intensity focused ultrasound (HIFU) for localized prostate cancer (PC). Patients without severe ED (International Index of Erectile Function-5 [IIEF-5] score ≥ 8) before focal HIFU therapy were included. A total of 92 of the 240 patients met the inclusion criteria and were included. The rate of severe ED (IIEF-5 ≤ 7) was 36% 12 months after treatment. Multivariable logistic regression analysis showed that the pre-procedural lower IIEF-5 score (odds ratio [OR] 0.812, p = 0.005), the pre-procedural lower score of the sexual domain of the Expanded Prostate Cancer Index Composite (OR 0.960, p = 0.038), and the treatment of the edge of the peripheral zone (PZ) in proximity to the neurovascular bundle (NVB) [treated vs. untreated, OR 8.048, p = 0.028] were significant risk factors for severe ED at 12 months after treatment. In conclusion, pre-procedural lower erectile function and treatment of the part in proximity to the NVB were significant risk factors for severe ED after focal therapy.