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.

The impact of telomere length on prostate cancer aggressiveness, genomic instability and health disparities.

The telomere repetitive TTAGGG motif at the ends of chromosomes, serves to preserve genomic integrity and chromosomal stability. In turn, genomic instability is a hallmark of cancer-implicating telomere disturbance. Prostate cancer (PCa) shows significant ancestral disparities, with men of African ancestry at the greatest risk for aggressive disease and associated genomic instability. Yet, no study has explored the role of telomere length (TL) with respect to ancestrally driven PCa health disparities. Patient- and technically-matched tumour-blood whole genome sequencing data for 179 ancestrally defined treatment naïve PCa patients (117 African, 62 European), we assessed for TL (blood and tumour) associations. We found shortened tumour TL to be associated with aggressive PCa presentation and elevated genomic instabilities, including percentage of genome alteration and copy number gains, in men of African ancestry. For European patients, tumour TL showed significant associations with PCa driver genes PTEN, TP53, MSH2, SETBP1 and DDX11L1, while shorter blood TL (< 3200 base pairs) and tumour TL (< 2861 base pairs) were correlated with higher risk for biochemical recurrence. Concurring with previous studies linking TL to PCa diagnosis and/or prognosis, for the first time we correlated TL differences with patient ancestry with important implications for future treatments targeting telomere dysfunction.

Prostate-specific membrane antigen positron emission tomography in addition to multiparametric magnetic resonance imaging and biopsies to select prostate cancer patients for focal therapy.

OBJECTIVE: To evaluate the additional value of prostate-specific membrane antigen positron emission tomography (PSMA-PET) to conventional diagnostic tools to select patients for hemi-ablative focal therapy (FT). PATIENTS AND METHODS: We performed a retrospective analysis on a multicentre cohort (private and institutional) of 138 patients who underwent multiparametric magnetic resonance imaging (mpMRI), PSMA-PET, and systematic biopsies prior to radical prostatectomy between January 2011 and July 2021. Patients were eligible when they met the consensus criteria for FT: PSA <15 ng/mL, clinical/radiological T stage ≤T2b, and International Society of Urological Pathology (ISUP) grade 2-3. Clinically significant prostate cancer (csPCa) was defined as ISUP grade ≥2, extracapsular extension >0.5 mm or seminal vesicle involvement at final histopathology. The diagnostic accuracy of mpMRI, systematic biopsies and PSMA-PET for csPCa (separate and combined) was calculated within a four-quadrant prostate model by receiver-operating characteristic and 2 × 2 contingency analysis. Additionally, we assessed whether the diagnostic tools correctly identified patients suitable for hemi-ablative FT. RESULTS: In total 552 prostate quadrants were analysed and 272 (49%) contained csPCa on final histopathology. The area under the curve, sensitivity, specificity, positive predictive value and negative predictive value for csPCa were 0.79, 75%, 83%, 81% and 77%, respectively, for combined mpMRI and systematic biopsies, and improved after addition of PSMA-PET to 0.84, 87%, 80%, 81% and 86%, respectively (P < 0.001). On final histopathology 46/138 patients (33%) were not suitable for hemi-ablative FT. Addition of PSMA-PET correctly identified 26/46 (57%) non-suitable patients and resulted in 4/138 (3%) false-positive exclusions. CONCLUSIONS: Addition of PSMA-PET to the conventional work-up by mpMRI and systematic biopsies could improve selection for hemi-ablative FT and guide exclusion of patients for whom whole-gland treatments might be a more suitable treatment option.

68Ga-PSMA-PET/CT in addition to mpMRI in men undergoing biopsy during active surveillance for low- to intermediate-risk prostate cancer: study protocol for a prospective cross-sectional study.

Background: In active surveillance there is significant interest in whether imaging modalities such as multiparametric magnetic resonance imaging (mpMRI) or 68Gallium prostate-specific membrane antigen positron emission tomography/computerized tomography (68Ga-PSMA-PET/CT) can improve the detection of progression to clinically significant prostate cancer (csPCa) and thus reduce the frequency of prostate biopsies and associated morbidity. Recent studies have demonstrated the value of mpMRI in active surveillance; however, mpMRI does miss a proportion of disease progression and thus alone cannot replace biopsy. To date, prostate-specific membrane antigen positron emission tomography (PSMA-PET) has shown additive value to mpMRI in its ability to detect prostate cancer (PCa) in the primary diagnostic setting. Our objective is to evaluate the diagnostic utility of PSMA-PET to detect progression to csPCa in active surveillance patients. Methods: We will perform a prospective, cross-sectional, partially blinded, multicentre clinical trial evaluating the additive value of PSMA-PET with mpMRI against saturation transperineal template prostate biopsy. Two hundred and twenty-five men will be recruited who have newly diagnosed PCa which is suitable for active surveillance. Following enrolment, patients will undergo a PSMA-PET and mpMRI within 3 months of a repeat 12-month confirmatory biopsy. Patients who remain on active surveillance after confirmatory biopsy will then be planned to have a further mpMRI and PSMA-PET prior to a repeat biopsy in 3-4 years. The primary outcome is to assess the ability of PSMA-PET to detect or exclude significant malignancy on repeat biopsy. Secondary outcomes include (I) assess the comparative diagnostic accuracies of mpMRI and PSMA-PET alone [sensitivity/specificity/negative predictive value (NPV)/positive predictive value (PPV)] to detect progression on biopsy based on predefined histologic criteria for progression; (II) comparison of index lesion identification by template biopsies vs. MRI targeted lesions vs. PSMA targeted lesions; (III) evaluation of concordance of lesions identified on final histopathology and each imaging modality (PSMA-PET and/or mpMRI) in the subset of patients proceeding to RP. Discussion: The results of this trial will define the role of PSMA-PET in active surveillance and potentially reduce the number of biopsies needed to detect progression to csPCa. Trial Registration: The current trial was registered with the ANZCTR on the 3/2/2022 with the trial ID ACTRN12622000188730, it is accessible at https://www.anzctr.org.au/.

Primary Whole-gland Ablation for the Treatment of Clinically Localized Prostate Cancer: A Focal Therapy Society Best Practice Statement.

CONTEXT: Whole-gland ablation is a feasible and effective minimally invasive treatment for localized prostate cancer (PCa). Previous systematic reviews supported evidence for favorable functional outcomes, but oncological outcomes were inconclusive owing to limited follow-up. OBJECTIVE: To evaluate the real-world data on the mid- to long-term oncological and functional outcomes of whole-gland cryoablation and high-intensity focused ultrasound (HIFU) in patients with clinically localized PCa, and to provide expert recommendations and commentary on these findings. EVIDENCE ACQUISITION: We performed a systematic review of PubMed, Embase, and Cochrane Library publications through February 2022 according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. As endpoints, baseline clinical characteristics, and oncological and functional outcomes were assessed. To estimate the pooled prevalence of oncological, functional, and toxicity outcomes, and to quantify and explain the heterogeneity, random-effect meta-analyses and meta-regression analyses were performed. EVIDENCE SYNTHESIS: Twenty-nine studies were identified, including 14 on cryoablation and 15 on HIFU with a median follow-up of 72 mo. Most of the studies were retrospective (n = 23), with IDEAL (idea, development, exploration, assessment, and long-term study) stage 2b (n = 20) being most common. Biochemical recurrence-free survival, cancer-specific survival, overall survival, recurrence-free survival, and metastasis-free survival rates at 10 yr were 58%, 96%, 63%, 71-79%, and 84%, respectively. Erectile function was preserved in 37% of cases, and overall pad-free continence was achieved in 96% of cases, with a 1-yr rate of 97.4-98.8%. The rates of stricture, urinary retention, urinary tract infection, rectourethral fistula, and sepsis were observed to be 11%, 9.5%, 8%, 0.7%, and 0.8%, respectively. CONCLUSIONS: The mid- to long-term real-world data, and the safety profiles of cryoablation and HIFU are sound to support and be offered as primary treatment for appropriate patients with localized PCa. When compared with other existing treatment modalities for PCa, these ablative therapies provide nearly equivalent intermediate- to long-term oncological and toxicity outcomes, as well as excellent pad-free continence rates in the primary setting. This real-world clinical evidence provides long-term oncological and functional outcomes that enhance shared decision-making when balancing risks and expected outcomes that reflect patient preferences and values. PATIENT SUMMARY: Cryoablation and high-intensity focused ultrasound are minimally invasive treatments available to selectively treat localized prostate cancer, considering their nearly comparable intermediate- to long term cancer control and preservation of urinary continence to other radical treatments in the primary setting. However, a well-informed decision should be made based on one's values and preferences.

Alterations in the Epigenetic Machinery Associated with Prostate Cancer Health Disparities.

Prostate cancer is driven by acquired genetic alterations, including those impacting the epigenetic machinery. With African ancestry as a significant risk factor for aggressive disease, we hypothesize that dysregulation among the roughly 656 epigenetic genes may contribute to prostate cancer health disparities. Investigating prostate tumor genomic data from 109 men of southern African and 56 men of European Australian ancestry, we found that African-derived tumors present with a longer tail of epigenetic driver gene candidates (72 versus 10). Biased towards African-specific drivers (63 versus 9 shared), many are novel to prostate cancer (18/63), including several putative therapeutic targets (CHD7, DPF3, POLR1B, SETD1B, UBTF, and VPS72). Through clustering of all variant types and copy number alterations, we describe two epigenetic PCa taxonomies capable of differentiating patients by ancestry and predicted clinical outcomes. We identified the top genes in African- and European-derived tumors representing a multifunctional "generic machinery", the alteration of which may be instrumental in epigenetic dysregulation and prostate tumorigenesis. In conclusion, numerous somatic alterations in the epigenetic machinery drive prostate carcinogenesis, but African-derived tumors appear to achieve this state with greater diversity among such alterations. The greater novelty observed in African-derived tumors illustrates the significant clinical benefit to be derived from a much needed African-tailored approach to prostate cancer healthcare aimed at reducing prostate cancer health disparities.

Novel radiomic analysis on bi-parametric MRI for characterizing differences between MR non-visible and visible clinically significant prostate cancer.

Background: around one third of clinically significant prostate cancer (CsPCa) foci are reported to be MRI non-visible (MRI─). Objective: To quantify the differences between MR visible (MRI+) and MRI─ CsPCa using intra- and peri-lesional radiomic features on bi-parametric MRI (bpMRI). Methods: This retrospective and multi-institutional study comprised 164 patients with pre-biopsy 3T prostate multi-parametric MRI from 2014 to 2017. The MRI─ CsPCa referred to lesions with PI-RADS v2 score < 3 but ISUP grade group > 1. Three experienced radiologists were involved in annotating lesions and PI-RADS assignment. The validation set (Dv) comprised 52 patients from a single institution, the remaining 112 patients were used for training (Dt). 200 radiomic features were extracted from intra-lesional and peri-lesional regions on bpMRI.Logistic regression with least absolute shrinkage and selection operator (LASSO) and 10-fold cross-validation was applied on Dt to identify radiomic features associated with MRI─ and MRI+ CsPCa to generate corresponding risk scores RMRI─ and RMRI+. RbpMRI was further generated by integrating RMRI─ and RMRI+. Statistical significance was determined using the Wilcoxon signed-rank test. Results: Both intra-lesional and peri-lesional bpMRI Haralick and CoLlAGe radiomic features were significantly associated with MRI─ CsPCa (p < 0.05). Intra-lesional ADC Haralick and CoLlAGe radiomic features were significantly different among MRI─ and MRI+ CsPCa (p < 0.05). RbpMRI yielded the highest AUC of 0.82 (95 % CI 0.72-0.91) compared to AUCs of RMRI+ 0.76 (95 % CI 0.63-0.89), and PI-RADS 0.58 (95 % CI 0.50-0.72) on Dv. RbpMRI correctly reclassified 10 out of 14 MRI─ CsPCa on Dv. Conclusion: Our preliminary results demonstrated that both intra-lesional and peri-lesional bpMRI radiomic features were significantly associated with MRI─ CsPCa. These features could assist in CsPCa identification on bpMRI.

The relationship between biochemical recurrence and number of lymph nodes removed during surgery for localized prostate cancer.

PURPOSE: To assess whether completeness of pelvic lymph node dissection (PLND) as measured by lymph node yield reduces biochemical recurrence (BCR) in men undergoing radical prostatectomy (RP) for prostate cancer (PCa), stratified according to Briganti nomogram-derived risk (≥5% vs. < 5%) of lymph node invasion (LNI). METHODS: Retrospective study of 3724 men who underwent RP between January 1995 and January 2015 from our prospectively collected institutional database. All men included had minimum five years follow-up and were not given androgen deprivation therapy or radiotherapy prior to BCR. Primary endpoint was time to BCR as defined by PSA > 0.2ng/ml. Patients were analysed according to Briganti Nomogram derived risk of 'low-risk' (< 5%) vs. 'high-risk' (≥ 5%). Extent of PLND was analysed using number of nodes yielded at dissection as a continuous variable as well as a categorical variable: Group 1 (limited, 1-4 nodes), Group 2 (intermediate, 5-8 nodes) and Group 3(extensive, ≥9 nodes). RESULTS: Median follow-up in the overall cohort was 79.7 months and 65% of the total cohort underwent PLND. There were 2402 patients with Briganti risk of LNI < 5% and 1322 with a Briganti risk of LNI ≥5%. At multivariate analysis, only PSA (HR1.01, p < 0.001), extracapsular extension at RP (HR 1.86, p < 0.001), positive surgical margin (HR 1.61, p < 0.001) and positive lymph node on pathology (HR 1.52, p = 0.02) were independently associated with BCR. In the high-risk group, increased nodal yield at PLND was associated with reduction in risk of BCR (HR 0.97, 95%CI 0.95-1.00 p = 0.05, Cochran Mantel Haenszel test, p < 0.05: respectively). In the low-risk group increased number of nodes at PLND did not reduce risk of BCR. CONCLUSIONS: In this study of extent of PLND at RP, higher nodal yield did not reduce risk of BCR in low-risk men (Briganti risk < 5%), however there was a weak benefit in terms of reduced long-term risk of BCR in high-risk men (Briganti risk ≥5%).

Median 4-year outcomes of salvage irreversible electroporation for localized radio-recurrent prostate cancer.

OBJECTIVES: To evaluate the safety, and short to mid-term oncological and quality-of-life (QoL) outcomes of focal irreversible electroporation (IRE) for radio-recurrent prostate cancer (PCa) at a median follow-up of 4 years. PATIENTS AND METHODS: This was a single-centre series of men with biopsy-proven radio-recurrent PCa treated with IRE between December 2013 and February 2022, with a minimum follow-up of 6 months. Follow-up included magnetic resonance imaging at 6 months, and standard transperineal saturation template biopsies at 12 months. Further biopsies were guided by suspicion on serial imaging or prostate-specific antigen (PSA) levels. Validated questionnaires were used to measure functional outcomes. Significant local recurrence was defined as any International Society of Urological Pathology (ISUP) score ≥ 2 on biopsies. Progression-free survival was defined as no signs of local or systemic disease on either imaging or template biopsies, or according to the Phoenix criteria for biochemical recurrence. RESULTS: Final analysis was performed on 74 men with radio-recurrent PCa (median age 69 years, median PSA level 5.4 ng/mL, 76% ISUP score 2/3). The median (range) follow-up was 48 (27-68) months. One rectal fistula occurred, and eight patients developed urethral sloughing that resolved with transurethral resection. Among patients who returned questionnaires (30/74, 41%), 93% (28/30) had preserved urinary continence and 23% (7/30) had sustained erectile function at 12-month follow-up. Local control was achieved in 57 patients (77%), who needed no further treatment. Biopsy diagnosed 41(55%) patients received follow up template biopsies, in-field recurrences occurred in 7% (3/41), and out-field recurrences occurred in 15% of patients (6/41). The metastasis-free survival rate was 91% (67/74), with a median (interquartile range) time to metastases of 8 (5-27) months. The Kaplan-Meier estimated 5-year progression-free survival rate was 60%. CONCLUSIONS: These short- to mid-term safety, oncological and QoL outcome data endorse results from smaller series and show the ability of salvage focal IRE to safely achieve oncological control in patients with radio-recurrent PCa.

Median 5-year outcomes of primary focal irreversible electroporation for localised prostate cancer.

OBJECTIVES: To evaluate longer-term oncological and functional outcomes of focal irreversible electroporation (IRE) as primary treatment for localised clinically significant prostate cancer (csPCa) at a median follow-up of 5 years (up to 10 years). PATIENTS AND METHODS: All patients that underwent focal IRE as primary treatment for localised PCa between February 2013 and August 2021 with a minimum 12 months of follow-up were analysed. Follow-up included 6-month magnetic resonance imaging (MRI) and standardised transperineal saturation template ± targeted biopsies at 12 months, and further biopsies in the case of clinical suspicion on serial imaging and/or prostate-specific antigen (PSA) levels. Failure-free survival (FFS) was defined as no progression to radical treatment or nodal/distant disease. Local recurrence was defined as any International Society of Urological Pathology Grade of ≥2 on biopsy. RESULTS: A total of 229 patients were analysed with a median (interquartile range [IQR]) follow-up of 60 (40-80) months. The median (IQR) age was 68 (64-74) years, the median (IQR) PSA level was 5.9 (4.1-8.2) ng/mL, and 86% harboured intermediate-risk disease and 7% high-risk disease. In all, 38 patients progressed to radical treatment (17%), at a median (IQR) of 35 (17-53) months after IRE. Kaplan-Meier FFS rates were 91% at 3 years, 84% at 5 years and 69% at 8 years. Metastasis-free survival was 99.6% (228/229), PCa-specific and overall survival were 100% (229/229). Residual csPCa was found in 24% (45/190) during follow-up biopsy and MRI showed a complete ablation in 82% (186/226). Short-term urinary continence was preserved (98%, three of 144 at baseline, 99%, one of 131 at 12 months) and erections sufficient for intercourse decreased by 13% compared to baseline (71% to 58%). CONCLUSION: Longer-term follow-up confirms our earlier findings that focal IRE provides acceptable local and distant oncological control in selected men with less urinary and sexual toxicity than radical treatment. Long-term follow-up and external validation of these findings, is required to establish this new treatment paradigm as a valid treatment option.

Salvage irreversible electroporation for radio-recurrent prostate cancer - the prospective FIRE trial.

OBJECTIVES: To prospectively assess the safety, functional- and oncological-outcomes of irreversible electroporation (IRE) as salvage therapy for radio-recurrent focal prostate cancer in a multicenter setting. PATIENTS AND METHODS: Men with focal recurrent PCa after external beam radiation or brachytherapy without metastatic disease on staging imaging and co-registration between mpMRI and biopsies were prospectively included in this multicenter trial. Adverse events were reported following the Clavien-Dindo classification. Validated questionnaires were used for patient-reported functional outcomes. Follow-up consisted of 3 monthly prostate specific antigen (PSA) levels, a 6-month mpMRI and standardised transperineal template mapping biopsies at 12-months. Thereafter follow-up was guided by MRI and/or PSMA-PET/CT and PSA. Local recurrence was defined as any ISUP score ≥2 on biopsies. RESULTS: 37 patients were analysed with a median (interquartile range (IQR)) follow up of 29 (22-43) months. Median age was 71 (53-83), median PSA was 3.5 ng/mL (2.7-6.1). 28 (75.5%) patients harboured intermediate risk and 9 patients (24.5%) high risk PCa. Seven patients (19%) reported self-limiting urgency, frequency, or hematuria (grade 1-2). Seven patients (19%) developed a grade 3 AE; urethral sludge requiring transurethral resection. At 12 months post treatment 93% of patients remained continent and erectile function sufficient for intercourse deteriorated from 35% to 15% (4/27). Local control was achieved in 29 patients (78%) and 27 patients (73%) were clear of local and systemic disease. Four (11%) patients had local recurrence only. Six (16%) patients developed metastatic disease with a median time to metastasis of 8 months. CONCLUSION: The FIRE trial shows that salvage IRE after failed radiation therapy for localised PCa is safe with minimal toxicity, and promising functional and oncological outcomes. Salvage IRE can offer a possible solution for notoriously difficult to manage radio recurrent prostate tumours.

Synchronous vs independent reading of prostate-specific membrane antigen positron emission tomography (PSMA-PET) and magnetic resonance imaging (MRI) to improve diagnosis of prostate cancer.

OBJECTIVES: To identify whether synchronous reading of multiparametric magnetic resonance imaging (mpMRI) and 68 Ga-PSMA-11 positron emission tomography (PET)/computed tomography (prostate-specific membrane antigen [PSMA-PET]) images can improve diagnostic performance and certainty compared with mpMRI/PSMA-PET reported independently and synthesized, while also assessing concordance between imaging modalities and agreement with histopathology. METHODS: This was a retrospective analysis of 100 patients randomly selected from the PRIMARY trial, a prospective Phase II multicentre imaging trial. Three dual-trained radiologist/nuclear medicine physicians re-reported the mpMRI and PSMA-PET both independently and synchronously for the same patients in random order, blinded to previous results. Diagnostic performance was assessed for mpMRI/PSMA-PET images read synchronously or independently and then synthesized. Agreement between imaging results and histopathology was examined. 'Concordance' between imaging modalities was defined as overlapping lesions. Reporting certainty was evaluated by the individual reporters for each modality. RESULTS: International Society of Urological Pathology Grade Group ≥2 cancer was present in 60% of patients on biopsy. Synchronous reading of mpMRI/PSMA-PET increased sensitivity compared to mpMRI or PSMA-PET alone (93% vs 80% vs 88%, respectively), although specificity was not improved (63% vs 58% vs 78%, respectively). No significant difference in diagnostic performance was noted between mpMRI/PSMA-PET read synchronously and mpMRI or PSMA-PET reported independently and then synthesized. Most patients had concordant imaging (60%), while others had discordant lesions only (28%) or a mixture (concordant and discordant lesions; 12%). When mpMRI/PSMA-PET findings were concordant and positive, 95% of patients had clinically significant prostate cancer (csPCa). When PSMA-PET alone was compared to synchronous PSMA-PET/MRI reads, there was an improvement in reader certainty in 20% of scans. CONCLUSION: Synchronous mpMRI/PSMA-PET reading improves reader certainty and sensitivity for csPCa compared to mpMRI or PSMA-PET alone. However, synthesizing the results of independently read PSMA-PET and mpMRI reports provided similar diagnostic performance to synchronous PSMA-PET/MRI reads. This may provide greater flexibility for urologists in terms of referral patterns, reducing healthcare system costs and improving efficiencies in prostate cancer diagnosis.

African-specific molecular taxonomy of prostate cancer.

Prostate cancer is characterized by considerable geo-ethnic disparity. African ancestry is a significant risk factor, with mortality rates across sub-Saharan Africa of 2.7-fold higher than global averages1. The contributing genetic and non-genetic factors, and associated mutational processes, are unknown2,3. Here, through whole-genome sequencing of treatment-naive prostate cancer samples from 183 ancestrally (African versus European) and globally distinct patients, we generate a large cancer genomics resource for sub-Saharan Africa, identifying around 2 million somatic variants. Significant African-ancestry-specific findings include an elevated tumour mutational burden, increased percentage of genome alteration, a greater number of predicted damaging mutations and a higher total of mutational signatures, and the driver genes NCOA2, STK19, DDX11L1, PCAT1 and SETBP1. Examining all somatic mutational types, we describe a molecular taxonomy for prostate cancer differentiated by ancestry and defined as global mutational subtypes (GMS). By further including Chinese Asian data, we confirm that GMS-B (copy-number gain) and GMS-D (mutationally noisy) are specific to African populations, GMS-A (mutationally quiet) is universal (all ethnicities) and the African-European-restricted subtype GMS-C (copy-number losses) predicts poor clinical outcomes. In addition to the clinical benefit of including individuals of African ancestry, our GMS subtypes reveal different evolutionary trajectories and mutational processes suggesting that both common genetic and environmental factors contribute to the disparity between ethnicities. Analogous to gene-environment interaction-defined here as a different effect of an environmental surrounding in people with different ancestries or vice versa-we anticipate that GMS subtypes act as a proxy for intrinsic and extrinsic mutational processes in cancers, promoting global inclusion in landmark studies.

Genome-wide interrogation of structural variation reveals novel African-specific prostate cancer oncogenic drivers.

BACKGROUND: African ancestry is a significant risk factor for advanced prostate cancer (PCa). Mortality rates in sub-Saharan Africa are 2.5-fold greater than global averages. However, the region has largely been excluded from the benefits of whole genome interrogation studies. Additionally, while structural variation (SV) is highly prevalent, PCa genomic studies are still biased towards small variant interrogation. METHODS: Using whole genome sequencing and best practice workflows, we performed a comprehensive analysis of SVs for 180 (predominantly Gleason score ≥ 8) prostate tumours derived from 115 African, 61 European and four ancestrally admixed patients. We investigated the landscape and relationship of somatic SVs in driving ethnic disparity (African versus European), with a focus on African men from southern Africa. RESULTS: Duplication events showed the greatest ethnic disparity, with a 1.6- (relative frequency) to 2.5-fold (count) increase in African-derived tumours. Furthermore, we found duplication events to be associated with CDK12 inactivation and MYC copy number gain, and deletion events associated with SPOP mutation. Overall, African-derived tumours were 2-fold more likely to present with a hyper-SV subtype. In addition to hyper-duplication and deletion subtypes, we describe a new hyper-translocation subtype. While we confirm a lower TMPRSS2-ERG fusion-positive rate in tumours from African cases (10% versus 33%), novel African-specific PCa ETS family member and TMPRSS2 fusion partners were identified, including LINC01525, FBXO7, GTF3C2, NTNG1 and YPEL5. Notably, we found 74 somatic SV hotspots impacting 18 new candidate driver genes, with CADM2, LSAMP, PTPRD, PDE4D and PACRG having therapeutic implications for African patients. CONCLUSIONS: In this first African-inclusive SV study for high-risk PCa, we demonstrate the power of SV interrogation for the identification of novel subtypes, oncogenic drivers and therapeutic targets. Identifying a novel spectrum of SVs in tumours derived from African patients provides a mechanism that may contribute, at least in part, to the observed ethnic disparity in advanced PCa presentation in men of African ancestry.

Predictive Value of Cribriform and Intraductal Carcinoma for the Nomogram-based Selection of Prostate Cancer Patients for Pelvic Lymph Node Dissection.

OBJECTIVE: To assess the predictive value of biopsy-identified cribriform carcinoma and/or intraductal carcinoma (CR/IDC) within the Briganti and MSKCC nomograms predicting lymph node metastasis (LNM) in patients with primary prostate cancer (PCa). METHODS: We retrospectively included 393 PCa patients who underwent radical prostatectomy with extended pelvic lymph node dissection at 3 tertiary referral centers. We externally validated 2 prediction tools: the Briganti 2012 nomogram and the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram. Both nomograms were augmented with CR/IDC. The original model was compared with the CR/IDC-updated model using the likelihood ratio test. The performance of the prediction tools was assessed using calibration, discrimination, and clinical utility. RESULTS: Overall, 109 (28%) men were diagnosed with LNM. Calibration plots of the Briganti and MSKCC nomograms demonstrated an underestimation of the LNM risk across clinically relevant thresholds (≤15%). The addition of CR/IDC to the Briganti nomogram increased the fit of the data (χ2(1) = 4.30, P = .04), but did not improve the area under the curve (AUC) (0.69, 95% CI 0.63-0.75 vs 0.69, 95% CI 0.64-0.75). Incorporation of CR/IDC in the MSKCC nomogram resulted in an increased fit on the data (χ2(1) = 10.04, P <.01), but did not increase the AUC (0.66, 95% CI 0.60-0.72 vs 0.68, 95% CI 0.62-0.74). The addition of CR/IDC to the Briganti and MSKCC nomograms did not improve the clinical risk prediction. CONCLUSION: Incorporation of CR/IDC into the 2 clinically most used pre-radical prostatectomy nomograms does not improve LNM prediction in a multinational, contemporary PCa cohort.

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging to Detect Residual Prostate Cancer Following Irreversible Electroporation-A Multicenter Validation Study.

BACKGROUND: Accurate monitoring following focal treatment of prostate cancer (PCa) is paramount for timely salvage treatment or retreatment. OBJECTIVE: To evaluate the diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI) to detect residual PCa in the short-term follow-up of focal treatment with irreversible electroporation (IRE) using transperineal or transrectal template ± targeted biopsies. DESIGN, SETTING, AND PARTICIPANTS: A retrospective international multicenter study of men with biopsy-proven PCa, treated with focal IRE, and followed by mpMRI (index-test) and template biopsies (reference-test) between February 2013 and January 2021, was conducted. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of mpMRI were calculated for in- and outfield residual disease based on two definitions of significant PCa: University College London (UCL) 1-International Society of Urological Pathology (ISUP) ≥3 or ISUP ≥1 with maximum cancer core length (MCCL) ≥6 mm, and UCL2-ISUP ≥2 or ISUP ≥1 with MCCL ≥4 mm. RESULTS AND LIMITATIONS: A total of 303 patients from five focal therapy centers were treated with primary IRE. The final analysis was performed on 217 men (median age 67, median prostate-specific antigen 6.2, 81% ISUP 2/3) who underwent both mpMRI and template biopsies. Multiparametric MRI missed 38/57 (67%) positive biopsy locations (UCL1) in 22 patients. Sensitivity, specificity, PPV, and NPV of mpMRI to detect whole gland residual disease (UCL1) were 43.6% (95% confidence interval [CI]: 28-59), 80.9% (95% CI: 75-86), 33.3% (95% CI: 21-47), and 86.7% (95% CI: 81-91), respectively. Based on UCL2, sensitivity, specificity, PPV, and NPV were 35.8% (95% CI: 25-48), 82.0% (95% CI: 75-88), 47.1% (95% CI: 34-61), and 74.1% (95% CI: 67-80), respectively. Limitations are the retrospective nature and short follow-up. CONCLUSIONS: The diagnostic accuracy of mpMRI to detect residual clinically significant PCa following IRE was low. Follow-up template biopsies should be performed, regardless of mpMRI results. PATIENT SUMMARY: We investigated the accuracy of magnetic resonance imaging (MRI) to detect residual prostate cancer after treatment with irreversible electroporation. The accuracy of MRI is insufficient, and we emphasize the importance of confirmatory prostate biopsies.

Outcomes of salvage radical prostatectomy after initial irreversible electroporation treatment for recurrent prostate cancer.

OBJECTIVE: To evaluate: (i) safety, (ii) feasibility, and medium-term (iii) oncological and (iv) functional outcomes of salvage radical prostatectomy (sRP) for recurrent localised prostate cancer (PCa) following initial focal therapy using irreversible electroporation (IRE). PATIENTS AND METHODS: An international, multicentre and retrospective analysis of prospectively collected data of patients that underwent sRP for recurrent localised PCa after initial primary IRE treatment. Data were reported on (i) surgical complications, (ii) feasibility of sRP reported by surgeons, (iii) time interval between IRE and sRP and pathology results, and (iv) urinary continence, erectile function, and quality of life. RESULTS: In four participating centres, a total of 39 patients with a median (interquartile range [IQR]) age 64 (60-67) years were identified. No serious adverse events occurred during or following sRP and surgery was deemed feasible without difficulties. The median (IQR) time to recurrence following IRE was 14.3 (9.1-38.8) months. Pathology results showed localised disease in 21 patients (53.8%) and locally-advanced disease in 18 (46.2%). Positive surgical margins (PSMs) were observed in 10 patients (25.6%), of which six (15.4%) had significant PSMs. A persistent detectable prostate-specific antigen level was found in one case after sRP, caused by metastatic disease. One patient had a biochemical recurrence 6 months after sRP. These two cases, together with a PSM case, required additional therapy after sRP. After a median (IQR) follow-up of 17.7 (11.8-26.4) months, urinary continence and erectile function were preserved in 34 (94.4%) and 18 patients (52.9%), respectively, while quality of life remained stable. CONCLUSIONS: Salvage RP is safe and feasible for patients with recurrent localised PCa following initial IRE treatment. The medium-term oncological and functional outcomes are similar to primary RP. Strict patient selection for focal therapy and standardised follow-up is needed as some patients developed high-grade disease.

Robot-Assisted Prostate-Specific Membrane Antigen-Radioguided Surgery in Primary Diagnosed Prostate Cancer.

The objective of this study was to evaluate the safety and feasibility of 99mTc-based prostate-specific membrane antigen (PSMA) robot-assisted-radioguided surgery to aid or improve the intraoperative detection of lymph node metastases during primary robot-assisted radical prostatectomy (RARP) for prostate cancer (PCa). Methods: Men with primary high-risk PCa (≥ cT3a, International Society of Urological Pathology (ISUP) grade group ≥ 3 or prostate-specific antigen of ≥ 15 ng/mL) with potential lymph node metastasis (Briganti nomogram risk > 10% or on preoperative imaging) were enrolled in the study. Patients underwent staging 68Ga-PSMA PET/CT scanning. Preoperatively, a 99mTc-labeled PSMA ligand (99mTc PSMA I&S; 500 MBq) was administered followed by SPECT/CT. A RARP including extended pelvic lymph node dissection was performed, with intraoperative tracing of PSMA-avid tissues using a prototype DROP-IN γ-probe. Resected specimens were also measured ex vivo. Histopathologic concordance with probe findings was evaluated. A radiotracer count of ≥ 1.5 times the background reference (in vivo), and ≥ 10 (absolute count) in the ex vivo setting, was considered positive. Results: Twelve patients were included (median age, 68 y, and prostate-specific antigen, 9.15 ng/mL). Most of the patients harbored ISUP 5 PCa (75%) and had avid lymph nodes on preoperative PSMA PET (64%). The DROP-IN probe aided resection of PSMA-avid (out-of-template) lymph nodes and residual disease at the prostate bed. Eleven metastatic lymph nodes were identified by the probe that were not observed on preoperative 68Ga-PSMA PET/CT. Of the 74 extraprostatic tissue specimens that were resected, 22 (29.7%) contained PCa. The sensitivity, specificity, positive predictive value, and negative predictive value of inpatient use of the γ-probe were 76% (95% CI, 53%-92%), 69% (95% CI, 55%-81%), 50%, and 88%, respectively. Ex vivo, the diagnostic accuracy was superior: 76% (95% CI, 53%-92%), 96% (95% CI, 87%-99%), 89%, and 91%, respectively, for sensitivity, specificity, positive predictive value, and negative predictive value. Of the missed lymph nodes in vivo (n = 5) and ex vivo (n = 5), 90% were micrometastasis (≤3 mm). No complications greater than Clavien-Dindo Grade I occurred. Conclusion: Robot-assisted 99mTc-based PSMA-radioguided surgery is feasible and safe in the primary setting, optimizing the detection of nodal metastases at the time of RARP and extended pelvic lymph node dissection. Further improvement of the detector technology may optimize the capabilities of robot-assisted 99mTc-based PSMA-radioguided surgery.