Rucaparib in Men With Metastatic Castration-Resistant Prostate Cancer Harboring a BRCA1 or BRCA2 Gene Alteration

Prostatic adenocarcinoma: molecular underpinnings and treatment-related options

Prostate cancer is heterogeneous with varied pathologic features and presents with a wide spectrum of clinical manifestations from indolent to advanced cancer. Interrogation of the molecular landscape of prostate cancer has unveiled the complex genomic alterations in these tumors, which significantly impacts tumor biology. The documented array of chromosomal alterations, gene fusions, and epigenetic changes not only play a crucial role in oncogenesis and disease progression, but also impacts response and resistance to various therapeutic modalities. Various gene expression assays have been developed and are currently recommended in aiding clinical decision making in these clinically and molecularly heterogeneous cancer. In this review, we provide an overview of the molecular underpinnings of prostate cancer, and briefly review the current status of molecular testing and therapeutic options in the management of these tumors.

The 5-WS of targeting DNA-damage repair (DDR) pathways in prostate cancer

DNA-damage repair (DDR) pathways alterations, a growing area of interest in oncology, are detected in about 20% of patient with prostate cancer and are associated with improved sensitivity to poly(ADP ribose) polymerases (PARP) inhibitors. In May 2020, the Food and Drug Administration (FDA) approved two PARP inhibitors (olaparib and rucaparib) for prostate cancer treatment. Moreover, germline aberrations in DDR pathways genes have also been related to familial or hereditary prostate cancer, requiring tailored health-care programs. These emerging scenarios are rapidly changing diagnostic, prognostic and therapeutic approaches in prostate cancer management. The aim of this review is to highlight the five W-points of DDR pathways in prostate cancer: why targeting DDR pathways in prostate cancer; what we should test for genomic profiling in prostate cancer; "where" testing genetic assessment in prostate cancer (germline or somatic, solid or liquid biopsy); when genetic testing is appropriate in prostate cancer; who could get benefit from PARP inhibitors; how improve patients outcome with combinations strategies.

Association of PARP inhibitor treatment on the prevalence and progression of clonal hematopoiesis in patients with advanced prostate cancer

BACKGROUND

Poly ADP-ribose polymerase (PARP) inhibitors are approved for the treatment of some men with advanced prostate cancer. Rare but serious side effects include myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The impact of PARP inhibitors on clonal hematopoiesis (CH), a potential precursor lesion associated with MDS and AML, is incompletely understood in prostate cancer. We hypothesized that PARP inhibitors would increase CH prevalence and abundance.

METHODS

We prospectively enrolled participants with advanced prostate cancer treated with PARP inhibitors. The presence of CH was assessed from leukocytes using an ultra-deep error-corrected dual unique molecular identifiers sequencing method targeting 49 genes most commonly mutated in CH and myeloid malignancies. Variant allele frequencies (VAF) of ≥0.5% were considered clinically significant. Blood samples were collected before and after PARP inhibitor treatment.

RESULTS

Ten men were enrolled; mean age of 67 years. Six patients had Gleason 7 disease, and four had Gleason ≥8 disease at diagnosis. Nine had localized disease at diagnosis, and eight had prior treatment with radiation. The mean time between pre- and post-treatment blood samples was 11 months (range 2.6-31 months). Six patients (60%) had CH identified prior to PARP inhibitor treatment, three with multiple clones. Of 11 CH clones identified in follow-up, 5 (45%) appeared or increased after treatment. DNMT3A, TET2, and PPM1D were the most common CH alterations observed. The largest post-treatment increase involved the PPM1D gene.

CONCLUSION

CH alterations are frequently found after treatment with PARP inhibitors in patients with prostate cancer and this may be one mechanism by which PARP inhibitors lead to increased risk of MDS/AML.

Expert Consensus Recommendations on the Management of Treatment-emergent Adverse Events Among Men with Prostate Cancer Taking Poly-ADP Ribose Polymerase Inhibitor + Novel Hormonal Therapy Combination Therapy

BACKGROUND AND OBJECTIVE

Recent clinical trials have shown improvement in progression-free survival in men with metastatic prostate cancer (mPC) treated with combination poly-ADP ribose polymerase (PARP) inhibitors (PARPi) and novel hormonal therapy (NHT). Regulatory bodies in the USA, Canada, Europe, and Japan have recently approved this combination therapy for mPC. Common adverse events (AEs) include fatigue, nausea and vomiting, and anemia. Nuanced AE management guidance for these combinations is lacking. The panel objective was to develop expert consensus on AE management in patients with mPC treated with the combination PARPi + NHT.

METHODS

The RAND/University of California Los Angeles modified Delphi Panel method was used. AEs were defined using the Common Terminology Criteria for Adverse Events. Twelve experts (seven medical oncologists, one advanced practice registered nurse, three urologists, and one patient advocate) reviewed the relevant literature; independently rated initial AE management options for the agent suspected of causing the AE for 419 patient scenarios on a 1-9 scale; discussed areas of agreement (AoAs) and disagreement (AoDs) at a March 2023 meeting; and repeated these ratings following the meeting. Second-round ratings formed the basis of guidelines.

KEY FINDINGS AND LIMITATIONS

AoDs decreased from 41% to 21% between the first and second round ratings, with agreement on at least one management strategy for every AE. AoAs included the following: (1) continue therapy with symptomatic treatment for patients with mild AEs; (2) for moderate fatigue, recommend nonpharmacologic treatment, hold treatment temporarily, and restart at a reduced dose when symptoms resolve; (3) for severe nausea or any degree of vomiting where symptomatic treatment fails, hold treatment temporarily and restart at a reduced dose when symptoms resolve; and (4) for hemoglobin 7.1-8.0 g/dl and symptoms of anemia, hold treatment temporarily and restart at a reduced dose after red blood cell transfusion.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This expert guidance can support management of AEs in patients with mPC receiving combination PARPi + NHT therapy.

PATIENT SUMMARY

A panel of experts developed guidelines for adverse event (AE) management in patients with metastatic prostate cancer treated with a combination of poly-ADP ribose polymerase inhibitors and novel hormonal therapy. For mild AEs, continuation of cancer therapy along with symptomatic treatment is recommended. For moderate or severe AEs, cancer therapy should be stopped temporarily and restarted at the same or a reduced dose when AE resolves.

Thio-2 Inhibits Key Signaling Pathways Required for the Development and Progression of Castration-resistant Prostate Cancer

Therapies that abrogate persistent androgen receptor (AR) signaling in castration-resistant prostate cancer (CRPC) remain an unmet clinical need. The N-terminal domain of the AR that drives transcriptional activity in CRPC remains a challenging therapeutic target. Herein we demonstrate that BCL-2-associated athanogene-1 (BAG-1) mRNA is highly expressed and associates with signaling pathways, including AR signaling, that are implicated in the development and progression of CRPC. In addition, interrogation of geometric and physiochemical properties of the BAG domain of BAG-1 isoforms identifies it to be a tractable but challenging drug target. Furthermore, through BAG-1 isoform mouse knockout studies, we confirm that BAG-1 isoforms regulate hormone physiology and that therapies targeting the BAG domain will be associated with limited "on-target" toxicity. Importantly, the postulated inhibitor of BAG-1 isoforms, Thio-2, suppressed AR signaling and other important pathways implicated in the development and progression of CRPC to reduce the growth of treatment-resistant prostate cancer cell lines and patient-derived models. However, the mechanism by which Thio-2 elicits the observed phenotype needs further elucidation as the genomic abrogation of BAG-1 isoforms was unable to recapitulate the Thio-2-mediated phenotype. Overall, these data support the interrogation of related compounds with improved drug-like properties as a novel therapeutic approach in CRPC, and further highlight the clinical potential of treatments that block persistent AR signaling which are currently undergoing clinical evaluation in CRPC.

Development of Novel Models of Aggressive Variants of Castration-resistant Prostate Cancer

BACKGROUND

Genomic studies have identified new subsets of aggressive prostate cancer (PCa) with poor prognosis (eg, neuroendocrine prostate cancer [NEPC], PCa with DNA damage response [DDR] alterations, or PCa resistant to androgen receptor pathway inhibitors [ARPIs]). Development of novel therapies relies on the availability of relevant preclinical models.

OBJECTIVE

To develop new preclinical models (patient-derived xenograft [PDX], PDX-derived organoid [PDXO], and patient-derived organoid [PDO]) representative of the most aggressive variants of PCa and to develop a new drug evaluation strategy.

DESIGN, SETTING, AND PARTICIPANTS

NEPC (n = 5), DDR (n = 7), and microsatellite instability (MSI)-high (n = 1) PDXs were established from 51 patients with metastatic PCa; PDXOs (n = 16) and PDOs (n = 6) were developed to perform drug screening. Histopathology and treatment response were characterized. Molecular profiling was performed by whole-exome sequencing (WES; n = 13), RNA sequencing (RNA-seq; n = 13), and single-cell RNA-seq (n = 14). WES and RNA-seq data from patient tumors were compared with the models.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Relationships with outcome were analyzed using the multivariable chi-square test and the tumor growth inhibition test.

RESULTS AND LIMITATIONS

Our PDXs captured both common and rare molecular phenotypes and their molecular drivers, including alterations of BRCA2, CDK12, MSI-high status, and NEPC. RNA-seq profiling demonstrated broad representation of PCa subtypes. Single-cell RNA-seq indicates that PDXs reproduce cellular and molecular intratumor heterogeneity. WES of matched patient tumors showed preservation of most genetic driver alterations. PDXOs and PDOs preserve drug sensitivity of the matched tissue and can be used to determine drug sensitivity.

CONCLUSIONS

Our models reproduce the phenotypic and genomic features of both common and aggressive PCa variants and capture their molecular heterogeneity. Successfully developed aggressive-variant PCa preclinical models provide an important tool for predicting tumor response to anticancer therapy and studying resistance mechanisms.

PATIENT SUMMARY

In this report, we looked at the outcomes of preclinical models from patients with metastatic prostate cancer enrolled in the MATCH-R trial (NCT02517892).

Molecular Pathology of Prostate Cancer

Molecular profiling studies have shed new light on the complex biology of prostate cancer. Genomic studies have highlighted that structural rearrangements are among the most common recurrent alterations. In addition, both germline and somatic mutations in DNA repair genes are enriched in patients with advanced disease. Primary prostate cancer has long been known to be multifocal, but recent studies demonstrate that a large fraction of prostate cancer shows evidence of multiclonality, suggesting that genetically distinct, independently arising tumor clones coexist. Metastatic prostate cancer shows a high level of morphologic and molecular diversity, which is associated with resistance to systemic therapies. The resulting high level of intratumoral heterogeneity has important implications for diagnosis and poses major challenges for the implementation of molecular studies. Here we provide a concise review of the molecular pathology of prostate cancer, highlight clinically relevant alterations, and discuss opportunities for molecular testing.

Pembrolizumab and Enzalutamide in Patients with Abiraterone Acetate-Pretreated Metastatic Castration-Resistant Prostate Cancer: Cohort C of the Phase 1b/2 KEYNOTE-365 Study

BACKGROUND

Limited responses have been observed in patients treated with enzalutamide after disease progression on abiraterone for metastatic castration-resistant prostate cancer (mCRPC), but androgen receptor signaling impacts T-cell function.

OBJECTIVE

To evaluate the efficacy and safety of pembrolizumab plus enzalutamide in mCRPC.

DESIGN, SETTING, AND PARTICIPANTS

Patients in cohort C of the phase 1b/2 KEYNOTE-365 study, who received ≥4 wk of treatment with abiraterone acetate in the prechemotherapy mCRPC state and experienced treatment failure or became drug-intolerant, were included.

INTERVENTION

Pembrolizumab 200 mg intravenously every 3 wk plus enzalutamide 160 mg orally once daily.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoints were safety, the confirmed prostate-specific antigen (PSA) response rate, and the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors version 1.1 on blinded independent central review (BICR). Secondary endpoints included radiographic progression-free survival (rPFS) on BICR and overall survival (OS).

RESULTS AND LIMITATIONS

A total of 102 patients received pembrolizumab plus enzalutamide. Median follow-up was 51 mo (interquartile range 37-56). The confirmed PSA response rate was 24% (95% confidence interval [CI] 16-33%). The confirmed ORR was 11% (95% CI 2.9-25%; 4/38 patients; two complete responses). Median rPFS was 6.0 mo (95% CI 4.1-6.3). Median OS was 20 mo (95% CI 17-24). Treatment-related adverse events (TRAEs) occurred in 94 patients (92%); grade 3-5 TRAEs occurred in 44 patients (43%). The incidence of treatment-related rash was higher with combination therapy than expected from the safety profile of each drug. One patient (1.0%) died of a TRAE (cause unknown). Study limitations include the single-arm design.

CONCLUSIONS

Pembrolizumab plus enzalutamide had limited antitumor activity in patients who received prior abiraterone treatment without previous chemotherapy for mCRPC, with a safety profile consistent with the individual profiles of each agent.

PATIENT SUMMARY

Pembrolizumab plus enzalutamide showed limited antitumor activity and manageable safety in patients with metastatic castration-resistant prostate cancer. The KEYNOTE-365 trial is registered on ClinicalTrials.gov as NCT02861573.

Talazoparib in Patients With Solid Tumors With BRCA1/2 Mutation: Results From the Targeted Agent and Profiling Utilization Registry Study

PURPOSE

The Targeted Agent and Profiling Utilization Registry Study is a phase II basket trial evaluating the antitumor activity of commercially available targeted agents in patients with advanced cancer and genomic alterations known to be drug targets. Results of a cohort of patients with various solid tumors with germline or somatic BRCA1/2 mutations treated with talazoparib are reported.

METHODS

Eligible patients had advanced solid tumors, measurable disease (RECIST), Eastern Cooperative Oncology Group performance status 0-2, adequate organ function, and no standard treatment options. Patients with germline BRCA-mutated human epidermal growth factor receptor 2-negative locally advanced or metastatic breast cancer were not eligible for this study. Primary end point was disease control (DC) determined by investigator assessment of objective response (OR) or stable disease (SD) of at least 16 weeks duration (SD16+). The results were evaluated on the basis of a one-sided exact binomial test with a null DC rate of 15% versus 35% (power = 0.82; α = .10). Secondary end points were OR, progression-free survival, overall survival, duration of response, duration of SD, and safety.

RESULTS

Twenty-eight patients (20 cancer types) with BRCA1/2 mutations were enrolled from December 2019 to September 2021 and collapsed into a single histology pooled cohort for analysis. All patients were evaluable for efficacy. One complete response, nine partial response, and six SD16+ were observed for DC and OR rates of 57% (one-sided 90% CI, 43 to 100) and 36% (95% CI, 19 to 56), respectively. The null hypothesis of a 15% DC rate was rejected (P < .001). Patients with OR had the following tumor types: breast (2), nonmelanoma skin, mesothelioma, stomach, uterus, non-small cell lung cancer, ovary, hepatocellular carcinoma, and pancreas. Thirteen patients had at least one grade 3-5 adverse event (AE) or serious AE at least possibly related to talazoparib. All were consistent with the drug label except bilirubin increase and hyponatremia (both grade 3 AEs).

CONCLUSION

Talazoparib demonstrated antitumor activity in patients with advanced solid tumors and BRCA1/2 mutations, including cancer types for which poly ADP-ribose polymerase inhibitors are not yet US Food and Drug Administration-approved.

Practical Guidance on Establishing a Molecular Testing Pathway for Alterations in Homologous Recombination Repair Genes in Clinical Practice for Patients with Metastatic Prostate Cancer

CONTEXT

Prostate cancer is a molecularly heterogeneous disease that is amenable to diagnostic testing to identify patients potentially eligible for personalised treatments inform familial risk and provide relevant information about potential prognosis. Several guidelines support the integration of genomic testing in a shared decision-making framework so that both health care professionals (HCPs) and patients are involved in determining the best treatment approach.

OBJECTIVE

To review current guidelines on molecular diagnostic testing for homologous recombination repair (HRR) gene alterations in patients with metastatic prostate cancer, with the aim of providing practical considerations for effective guideline implementation and establishment of an appropriate pathway for molecular diagnostic testing.

EVIDENCE ACQUISITION

We undertook a nonsystematic narrative review of the literature using PubMed to identify current guidelines and recommendations on molecular diagnostic testing for BRCA and/or homologous recombination repair gene alterations (HRRm) in patients with prostate cancer. In addition, selected articles that included BRCA/HRRm testing in clinical trials in metastatic castration-resistant prostate cancer and real-world evidence were also evaluated. Websites for relevant societies were reviewed for molecular diagnostic guidelines not published on PubMed.

EVIDENCE SYNTHESIS

Our review of guidelines published by several international societies that include molecular testing in prostate cancer identified variations in molecular testing approaches. The review of testing approaches used in clinical trials and real-world settings also highlighted several aspects that require improvement. Therefore, we compiled practical guidance for establishing an appropriate BRCA/HRR mutation testing pathway.

CONCLUSIONS

While there are several challenges to molecular testing and interpretation of test results that require enhancement, a multidisciplinary team approach will empower HCPs and their institutions to improve on or initiate their own molecular testing pathways. This in turn will lead to improvements in management strategies for patients with metastatic prostate cancer, for whom better treatment outcomes is a significant unmet need.

PATIENT SUMMARY

Establishing a molecular testing pathway in clinical practice for patients with metastatic castration-resistant prostate cancer will lead to fairer and more equal access to personalised treatments. This should lead to better outcomes, particularly for patients whose disease has spread to other areas of the body.

New target therapies in prostate cancer: from radioligand therapy, to PARP-inhibitors and immunotherapy

Prostate cancer (PCa) remains a significant global health challenge, particularly in its advanced stages. Despite progress in early detection and treatment, PCa is the second most common cancer diagnosis among men. This review aims to provide an overview of current therapeutic approaches and innovations in PCa management, focusing on the latest advancements and ongoing challenges. We conducted a narrative review of clinical trials and research studies, focusing on PARP inhibitors (PARPis), phosphoinositide 3 kinase-protein kinase B inhibitors, immunotherapy, and radioligand therapies (RLTs). Data was sourced from major clinical trial databases and peer-reviewed journals. Androgen deprivation therapy and androgen-receptor pathway inhibitors remain foundational in managing castration-sensitive and early-stage castration-resistant PCa (CRPC). PARPi's, such as olaparib and rucaparib, have emerged as vital treatments for metastatic CRPC with homologous recombination repair gene mutations, highlighting the importance of personalized medicine. Immune checkpoint inhibitors (ICIs) have shown clinical benefit limited to specific subgroups of PCa, demonstrating significant improvement in efficacy in patients with microsatellite instability/mismatch repair or cyclin-dependent kinase 12 alteration, highlighting the importance of focusing ongoing research on identifying and characterizing these subgroups to maximize the clinical benefits of ICIs. RLTs have shown effectiveness in treating mCRPC. Different alpha emitters (like [225Ac]PSMA) and beta emitters compounds (like [177Lu]PSMA) impact treatment differently due to their energy transfer characteristics. Clinical trials like VISION and TheraP have demonstrated positive outcomes with RLT, particularly [177Lu]PSMA-617, leading to FDA approval. Ongoing trials and future perspectives explore the potential of [225Ac]PSMA, aiming to improve outcomes for patients with mCRPC. The landscape of PCa treatment is evolving, with significant advancements in both established and novel therapies. The combination of hormonal therapies, chemotherapy, PARPis, immunotherapy, and RLTs, guided by genetic and molecular insights, opens new possibilities for personalized treatment.

Poly (ADP-ribose) Polymerase Inhibitors Have Comparable Efficacy with Platinum Chemotherapy in Patients with BRCA-positive Metastatic Castration-resistant Prostate Cancer. A Systematic Review and Meta-analysis

CONTEXT

Testing for mutations in Breast Cancer Gene 1/2 (BRCA) has emerged as a novel decision-making tool for clinicians. Patients with metastatic castration-resistant prostate cancer (mCRPC) harboring pathogenic BRCA mutations can benefit from poly (ADP-ribose) polymerase inhibitor (PARPi) and platinum treatments, whereas the impact of the mutation on sensitivity to cabazitaxel and prostate-specific membrane antigen (PSMA)-ligand therapy is currently unknown.

OBJECTIVE

To assess the efficacy of PARPi, platinum, cabazitaxel, and PSMA-ligand therapies in BRCA-positive mCRPC.

EVIDENCE ACQUISITION

Databases were queried in February 2022. We performed data synthesis by using both proportional and individual patient data. For prostate-specific antigen (PSA) response rate (≥50% decrease from baseline [PSA50]) evaluation, we pooled event rates with 95% confidence intervals (CIs). Progression-free (PFS) and overall (OS) survival analyses with individual patient data were performed with the mixed-effect Cox proportional hazard model and single-arm random-effect analysis, providing pooled medians.

EVIDENCE SYNTHESIS

We included 23 eligible studies with 901 BRCA-positive mCRPC patients. PSA50 response rates for PARPi and platinum were 69% (CI: 53-82%), and 74% (CI: 49-90%), respectively. Analyses of OS data showed no difference between PARPi and platinum treatments (hazard ratio: 0.86; CI: 0.49-1.52; p = 0.6). The single-arm OS and PFS analyses revealed similarities among different PARPis; pooled PFS and OS medians were 9.7 mo (CI: 8.1-12.5) and 17.4 mo (CI: 12.7-20.1), respectively.

CONCLUSIONS

Our data revealed that different PARPis were similarly effective in terms of PFS and OS. Moreover, we found that PARPi and platinum therapy were comparable in terms of PSA50 response rate and OS, highlighting that platinum is a valid treatment option for BRCA-positive mCRPC patients. However, prospective interventional studies comparing these agents are essential to provide a higher level of evidence.

PATIENT SUMMARY

In this report, we found that different poly (ADP-ribose) polymerase inhibitors had similar efficacy, and platinum was a valid treatment option in BRCA-positive metastatic castration-resistant prostate cancer patients.

Homologous Recombination Repair Gene Mutations in Prostate Cancer: Prevalence and Clinical Value

Despite advances in our understanding of the molecular landscape of prostate cancer and the development of novel biomarker-driven therapies, the prognosis of patients with metastatic prostate cancer that is resistant to conventional hormonal therapy remains poor. Data suggest that a significant proportion of patients with metastatic castration-resistant prostate cancer (mCRPC) have mutations in homologous recombination repair (HRR) genes and may benefit from poly(ADP-ribose) polymerase (PARP) inhibitors. However, the adoption of HRR gene mutation testing in prostate cancer remains low, meaning there is a missed opportunity to identify patients who may benefit from targeted therapy with PARP inhibition, with or without novel hormonal agents. Here, we review the current knowledge regarding the clinical significance of HRR gene mutations in prostate cancer and discuss the efficacy of PARP inhibition in patients with mCRPC. This comprehensive overview aims to increase the clinical implementation of HRR gene mutation testing and inform future efforts in personalized treatment of prostate cancer.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

Efficacy of Poly(ADP-ribose) Polymerase Inhibitors by Individual Genes in Homologous Recombination Repair Gene-Mutated Metastatic Castration-Resistant Prostate Cancer: A US Food and Drug Administration Pooled Analysis

PURPOSE

We performed a pooled analysis of multiple trials of poly(ADP-ribose) polymerase inhibitors (PARPi) in metastatic castration-resistant prostate cancer (mCRPC) to investigate the efficacy of PARPi in each individual homologous recombination repair (HRR) mutated (m) gene.

PATIENTS AND METHODS

We pooled patient-level data from trials of PARPi in mCRPC that reported mutation status in individual HRR genes. Any HRR gene with available data across all the randomized trials of PARPi in first-line mCRPC was selected. The hazard ratios (HRs; 95% CI) for radiographic progression-free survival (rPFS; by blinded independent review) and overall survival (OS) of a PARPi plus an androgen receptor pathway inhibitor (ARPI) relative to placebo plus an ARPI in the pool of three randomized trials in first-line mCRPC were calculated using Kaplan-Meier estimates and a Cox proportional hazards model.

RESULTS

In ATMm (N = 268), rPFS HR was 1.05 (0.74 to 1.49) and OS HR was 1.18 (0.82 to 1.71). In BRCA1m (N = 64), rPFS HR was 0.51 (0.23 to 1.1) and OS HR was 0.74 (0.34 to 1.61). In BRCA2m (N = 422), rPFS HR was 0.31 (0.23 to 0.42) and OS HR was 0.66 (0.49 to 0.89). In CDK12m (N = 164), rPFS HR was 0.50 (0.32 to 0.80) and OS HR was 0.63 (0.39 to 0.99). In CHEK2m (N = 172), rPFS HR was 1.06 (0.67 to 1.66) and OS HR was 1.53 (0.95 to 2.46). In PALB2m (N = 41) rPFS HR was 0.52 (0.23 to 1.17) and OS HR was 0.78 (0.34 to 1.8).

CONCLUSION

In this pooled analysis, benefit from PARPi appeared greatest for patients with BRCA1m, BRCA2m, CDK12m, and PALB2m. Given limitations of this exploratory analysis, the apparent lack of benefit from PARPi in patients with CHEK2m or ATMm should be further explored in future clinical trials.

Ductal, intraductal, and cribriform carcinoma of the prostate: Molecular characteristics and clinical management

Prostatic acinar adenocarcinoma accounts for approximately 95% of prostate cancer (CaP) cases. The remaining 5% of histologic subtypes of CaP are known to be more aggressive and have recently garnered substantial attention. These histologic subtypes - namely, prostatic ductal adenocarcinoma (PDA), intraductal carcinoma of the prostate (IDC-P), and cribriform carcinoma of the prostate (CC-P) - typically exhibit distinct growth characteristics, genomic features, and unique oncologic outcomes. For example, PTEN mutations, which cause uncontrolled cell growth, are frequently present in IDC-P and CC-P. Germline mutations in homologous DNA recombination repair (HRR) genes (e.g., BRCA1, BRCA2, ATM, PALB2, and CHEK2) are discovered in 40% of patients with IDC-P, while only 9% of patients without ductal involvement had a germline mutation. CC-P is associated with deletions in common tumor suppressor genes, including PTEN, TP53, NKX3-1, MAP3K7, RB1, and CHD1. Evidence suggests abiraterone may be superior to docetaxel as a first-line treatment for patients with IDC-P. To address these and other critical pathological attributes, this review examines the molecular pathology, genetics, treatments, and oncologic outcomes associated with CC-P, PDA, and IDC-P with the objective of creating a comprehensive resource with a centralized repository of information on PDA, IDC-P, and CC-P.

Incidental pathogenic germline alterations detected through liquid biopsy in patients with solid tumors: prevalence, clinical utility and implications

Liquid biopsy, a minimally invasive approach for detecting tumor biomarkers in blood, has emerged as a leading-edge technique in cancer precision medicine. New evidence has shown that liquid biopsies can incidentally detect pathogenic germline variants (PGVs) associated with cancer predisposition, including in patients with a cancer for which genetic testing is not recommended. The ability to detect these incidental PGV in cancer patients through liquid biopsy raises important questions regarding the management of this information and its clinical implications. This incidental identification of PGVs raises concerns about cancer predisposition and the potential impact on patient management, not only in terms of providing access to treatment based on the tumor molecular profiling, but also the management of revealing genetic predisposition in patients and families. Understanding how to interpret this information is essential to ensure proper decision-making and to optimize cancer treatment and prevention strategies. In this review we provide a comprehensive summary of current evidence of incidental PGVs in cancer predisposition genes identified by liquid biopsy in patients with cancer. We critically review the methodological considerations of liquid biopsy as a tool for germline diagnosis, clinical utility and potential implications for cancer prevention, treatment, and research.

Therapeutic biomarkers in metastatic castration-resistant prostate cancer: does the state matter?

The treatment of metastatic castration-resistant prostate cancer (mCRPC) has been fundamentally transformed by our greater understanding of its complex biological mechanisms and its entrance into the era of precision oncology. A broad aim is to use the extreme heterogeneity of mCRPC by matching already approved or new targeted therapies to the correct tumor genotype. To achieve this, tumor DNA must be obtained, sequenced, and correctly interpreted, with individual aberrations explored for their druggability, taking into account the hierarchy of driving molecular pathways. Although tumor tissue sequencing is the gold standard, tumor tissue can be challenging to obtain, and a biopsy from one metastatic site or primary tumor may not provide an accurate representation of the current genetic underpinning. Sequencing of circulating tumor DNA (ctDNA) might catalyze precision oncology in mCRPC, as it enables real-time observation of genomic changes in tumors and allows for monitoring of treatment response and identification of resistance mechanisms. Moreover, ctDNA can be used to identify mutations that may not be detected in solitary metastatic lesions and can provide a more in-depth understanding of inter- and intra-tumor heterogeneity. Finally, ctDNA abundance can serve as a prognostic biomarker in patients with mCRPC.The androgen receptor (AR)-axis is a well-established therapeutical target for prostate cancer, and through ctDNA sequencing, insights have been obtained in (temporal) resistance mechanisms that develop through castration resistance. New third-generation AR-axis inhibitors are being developed to overcome some of these resistance mechanisms. The druggability of defects in the DNA damage repair machinery has impacted the treatment landscape of mCRPC in recent years. For patients with deleterious gene aberrations in genes linked to homologous recombination, particularly BRCA1 or BRCA2, PARP inhibitors have shown efficacy compared to the standard of care armamentarium, but platinum-based chemotherapy may be equally effective. A hierarchy exists in genes associated with homologous recombination, where, besides the canonical genes in this pathway, not every other gene aberration predicts the same likelihood of response. Moreover, evidence is emerging on cross-resistance between therapies such as PARP inhibitors, platinum-based chemotherapy and even radioligand therapy that target this genotype. Mismatch repair-deficient patients can experience a beneficial response to immune checkpoint inhibitors. Activation of other cellular signaling pathways such as PI3K, cell cycle, and MAPK have shown limited success with monotherapy, but there is potential in co-targeting these pathways with combination therapy, either already witnessed or anticipated. This review outlines precision medicine in mCRPC, zooming in on the role of ctDNA, to identify genomic biomarkers that may be used to tailor molecularly targeted therapies. The most common druggable pathways and outcomes of therapies matched to these pathways are discussed.

First-line combination treatment with PARP and androgen receptor-signaling inhibitors in HRR-deficient mCRPC: Applying clinical study findings to clinical practice in the United States

INTRODUCTION

Metastatic castration-resistant prostate cancer (mCRPC) remains incurable and develops from biochemically recurrent PC treated with androgen deprivation therapy (ADT) following definitive therapy for localized PC, or from metastatic castration-sensitive PC (mCSPC). In the mCSPC setting, treatment intensification of ADT plus androgen receptor (AR)-signaling inhibitors (ARSIs), with or without chemotherapy, improves outcomes vs ADT alone. Despite multiple phase 3 trials demonstrating a survival benefit of treatment intensification in PC, there remains high use of ADT monotherapy in real-world clinical practice. Prior studies indicate that co-inhibition of AR and poly(ADP-ribose) polymerase (PARP) may result in enhanced benefit in treating tumors regardless of alterations in DNA damage response genes involved either directly or indirectly in homologous recombination repair (HRR). Three recent phase 3 studies evaluated the combination of a PARP inhibitor (PARPi) with an ARSI as first-line treatment for mCRPC: TALAPRO-2, talazoparib plus enzalutamide; PROpel, olaparib plus abiraterone acetate and prednisone (AAP); and MAGNITUDE, niraparib plus AAP. Results from these studies have led to the recent approval in the United States of talazoparib plus enzalutamide for the treatment of mCRPC with any HRR alteration, and of both olaparib and niraparib indicated in combination with AAP for the treatment of mCRPC with BRCA alterations.

SUMMARY

Here, we review the newly approved PARPi plus ARSI treatments within the context of the mCRPC treatment landscape, provide an overview of practical considerations for the combinations in clinical practice, highlight the importance of HRR testing, and discuss the benefits of treatment intensification for patients with mCRPC.

Treatment patterns and outcomes in metastatic castration-resistant prostate cancer patients with and without somatic or germline alterations in homologous recombination repair genes

BACKGROUND

Although germline BRCA mutations have been associated with adverse outcomes in prostate cancer (PC), understanding of the association between somatic/germline alterations in homologous recombination repair (HRR) genes and treatment outcomes in metastatic castration-resistant PC (mCRPC) is limited. The aim of this study was to investigate the prevalence and outcomes associated with somatic/germline HRR alterations, particularly BRCA1/2, in patients initiating first-line (1L) mCRPC treatment with androgen receptor signalling inhibitors (ARSi) or taxanes.

PATIENTS AND METHODS

Data from 729 mCRPC patients were pooled for CAPTURE from four multicentre observational studies. Eligibility required 1L treatment with ARSi or taxanes, adequate tumour samples and biomarker panel results. Patients underwent paired normal and tumour DNA analyses by next-generation sequencing using a custom gene panel including ATM, BRCA1, BRCA2, BRIP1, CDK12, CHEK2, FANCA, HDAC2, PALB2, RAD51B and RAD54L. Patients were divided into subgroups based on somatic/germline alteration(s): with BRCA1/2 mutations (BRCA); with HRR mutations except BRCA1/2 (HRR non-BRCA); and without HRR alterations (non-HRR). Patients without BRCA1/2 mutations were classified as non-BRCA. Radiographic progression-free survival (rPFS), progression-free survival 2 (PFS2) and overall survival (OS) were assessed.

RESULTS

Of 729 patients, 96 (13.2%), 127 (17.4%) and 506 (69.4%) were in the BRCA, HRR non-BRCA and non-HRR subgroups, respectively. BRCA patients performed significantly worse for all outcomes than non-HRR or non-BRCA patients (P < 0.05), while PFS2 and OS were significantly shorter for BRCA than HRR non-BRCA patients (P < 0.05). HRR non-BRCA patients also had significantly worse rPFS, PFS2 and OS than non-HRR patients. Exploratory analyses suggested that for BRCA patients, there were no significant differences in outcomes associated with 1L treatment choice (ARSi or taxanes) or with the somatic/germline origin of the alterations.

CONCLUSIONS

Worse outcomes were observed for mCRPC patients in the BRCA subgroup compared with non-BRCA subgroups, either HRR non-BRCA or non-HRR. Despite its heterogeneity, the HRR non-BRCA subgroup presented worse outcomes than the non-HRR subgroup. Screening early for HRR mutations, especially BRCA1/2, is crucial in improving mCRPC patient prognosis.

From biology to the clinic - exploring liver metastasis in prostate cancer

Liver metastases from prostate cancer are associated with an aggressive disease course and poor prognosis. Results from autopsy studies indicate a liver metastasis prevalence of up to 25% in patients with advanced prostate cancer. Population data estimate that ~3-10% of patients with metastatic castration-resistant prostate cancer harbour liver metastases at the baseline, rising to 20-30% in post-treatment cohorts, suggesting that selective pressure imposed by novel therapies might promote metastatic spread to the liver. Liver metastases are associated with more aggressive tumour biology than lung metastases. Molecular profiling of liver lesions showed an enrichment of low androgen receptor, neuroendocrine phenotypes and high genomic instability. Despite advancements in molecular imaging modalities such as prostate-specific membrane antigen PET-CT, and liquid biopsy markers such as circulating tumour DNA, early detection of liver metastases from prostate cancer remains challenging, as both approaches are hampered by false positive and false negative results, impeding the accurate identification of early liver lesions. Current therapeutic strategies showed limited efficacy in this patient population. Emerging targeted radionuclide therapies, metastasis-directed therapy, and novel systemic agents have shown preliminary activity against liver metastases, but require further validation. Treatment with various novel prostate cancer therapies might lead to an increase in the prevalence of liver metastasis, underscoring the urgent need for coordinated efforts across preclinical and clinical researchers to improve characterization, monitoring, and management of liver metastases from prostate cancer. Elucidating molecular drivers of liver tropism and interactions with the liver microenvironment might ultimately help to identify actionable targets to enhance survival in this high-risk patient group.

Discovery of Novel Potential Prognostic Markers and Targeted Therapy to Overcome Chemotherapy Resistance in an Advanced-Stage Wilms Tumor

Wilms tumor (WT), the most prevalent type of renal cancer in children, exhibits overall survival rates exceeding 90%. However, chemotherapy resistance, which occurs in approximately 10% of WT cases, is a major challenge for the treatment of WT, particularly for advanced-stage patients. In this study, we aimed to discover potential mutation markers and drug targets associated with chemotherapy resistance in advanced-stage WT. We performed exome sequencing to detect somatic mutations and molecular targets in 43 WT samples, comprising 26 advanced-stage WTs, of which 7 cases were chemotherapy-resistant. Our analysis revealed four genes (ALPK2, C16orf96, PRKDC, and SVIL) that correlated with chemotherapy resistance and reduced disease-free survival in advanced-stage WT. Additionally, we identified driver mutations in 55 genes within the chemotherapy-resistant group, including 14 druggable cancer driver genes. Based on the mutation profiles of the resistant WT samples, we propose potential therapeutic strategies involving platinum-based agents, PARP inhibitors, and antibiotic/antineoplastic agents. Our findings provide insights into the genetic landscape of WT and offer potential avenues for targeted treatment, particularly for patients with chemotherapy resistance.

Precision medicine for prostate cancer: An international perspective

Greater personalization of cancer medicine continues to shape therapy development and patient selection accordingly. The treatment of prostate cancer has evolved considerably since the discovery of androgen deprivation therapy. The comprehensive profiling of the prostate cancer genome has mapped the targetable molecular landscape of the disease and identified opportunities for the implementation of novel and combination therapies. In this review, we provide an overview of the molecular biology of prostate cancer and tools developed to aid prognostication and prediction of therapy benefit. Modern treatment of advanced prostate cancer is reviewed as a paradigm of increasing precision-informed approach to patient care, and must be considered on a global scale with respect to the state of science and care delivery.

Blocking lipid synthesis induces DNA damage in prostate cancer and increases cell death caused by PARP inhibition

Androgen deprivation therapy (ADT) is the primary treatment for prostate cancer; however, resistance to ADT invariably develops, leading to castration-resistant prostate cancer (CRPC). Prostate cancer progression is marked by increased de novo synthesis of fatty acids due to overexpression of fatty acid synthase (FASN), making this enzyme a therapeutic target for prostate cancer. Inhibition of FASN results in increased intracellular amounts of ceramides and sphingomyelin, leading to DNA damage through the formation of DNA double-strand breaks and cell death. We found that combining a FASNi with the poly-ADP ribose polymerase (PARP) inhibitor olaparib, which induces cell death by blocking DNA damage repair, resulted in a more pronounced reduction in cell growth than that caused by either drug alone. Human CRPC organoids treated with a combination of PARP and FASNi were smaller, had decreased cell proliferation, and showed increased apoptosis and necrosis. Together, these data indicate that targeting FASN increases the therapeutic efficacy of PARP inhibitors by impairing DNA damage repair, suggesting that combination therapies should be explored for CRPC.

Tolerability of Olaparib Combined with Abiraterone in Patients with Metastatic Castration-resistant Prostate Cancer: Further Results from the Phase 3 PROpel Trial

BACKGROUND

The PROpel study (NCT03732820) demonstrated a statistically significant progression-free survival benefit with olaparib plus abiraterone versus placebo plus abiraterone in the first-line metastatic castration-resistant prostate cancer (mCRPC) setting, irrespective of homologous recombination repair mutation status.

OBJECTIVE

We report additional safety analyses from PROpel to increase clinical understanding of the adverse-event (AE) profiles of olaparib plus abiraterone versus placebo plus abiraterone.

DESIGN, SETTING, AND PARTICIPANTS

A randomised (1:1), double-blind, placebo-controlled trial was conducted at 126 centres in 17 countries (October 2018-January 2020). Patients had mCRPC and no prior systemic mCRPC treatment.

INTERVENTION

Olaparib (300 mg bid) or placebo with abiraterone (1000 mg od) plus prednisone/prednisolone (5 mg bid).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The data cut-off date was July 30, 2021. Safety was assessed by AE reporting (Common Terminology Criteria for Adverse Events v4.03) and analysed descriptively.

RESULTS AND LIMITATIONS

The most common AEs (all grades) for olaparib plus abiraterone versus placebo plus abiraterone were anaemia (46.0% vs 16.4%), nausea (28.1% vs 12.6%), and fatigue (27.9% vs 18.9%). Grade ≥3 anaemia occurred in 15.1% versus 3.3% of patients in the olaparib plus abiraterone versus placebo plus abiraterone arm. The incidences of the most common AEs for olaparib plus abiraterone peaked early, within 2 mo, and were managed typically by dose modifications or standard medical practice. Overall, 13.8% versus 7.8% of patients discontinued treatment with olaparib plus abiraterone versus placebo plus abiraterone because of an AE; 3.8% versus 0.8% of patients discontinued because of anaemia. More venous thromboembolism events were observed in the olaparib plus abiraterone arm (any grade, 7.3%; grade ≥3, 6.8%) than in the placebo plus abiraterone arm (any grade, 3.3%; grade ≥3, 2.0%), most commonly pulmonary embolism (6.5% vs 1.8% for olaparib plus abiraterone vs placebo plus abiraterone).

CONCLUSIONS

Olaparib plus abiraterone has a manageable and predictable safety profile.

PATIENT SUMMARY

The PROpel trial showed that in patients who had not received any previous treatment for metastatic castration-resistant prostate cancer, olaparib combined with abiraterone was more effective in delaying progression of the disease than abiraterone alone. Most side effects caused by combining olaparib with abiraterone could be managed with supportive care methods, by pausing olaparib administration for a short period of time and/or by reducing the dose of olaparib.

Repeat Next-Generation Sequencing Testing on Progression in Men With Metastatic Prostate Cancer Can Identify New Actionable Alterations

PURPOSE

There are limited data available on the real-world patterns of molecular testing in men with advanced prostate cancer. We thus sought to evaluate next-generation sequencing (NGS) testing in the United States, focused on single versus serial NGS testing, the different disease states of testing (hormone-sensitive v castration-resistant, metastatic vs nonmetastatic), tissue versus plasma circulating tumor DNA (ctDNA) assays, and how often actionable data were found on each NGS test.

METHODS

The Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort clinical-genomic database was used for this retrospective analysis, including 1,597 patients across 15 institutions. Actionable NGS data were defined as including somatic alterations in homologous recombination repair genes, mismatch repair deficiency, microsatellite instability (MSI-high), or a high tumor mutational burden ≥10 mut/MB.

RESULTS

Serial NGS testing (two or more NGS tests with specimens collected more than 60 days apart) was performed in 9% (n = 144) of patients with a median of 182 days in between test results. For the second NGS test and beyond, 82.1% (225 of 274) of tests were from ctDNA assays and 76.1% (217 of 285) were collected in the metastatic castration-resistant setting. New actionable data were found on 11.1% (16 of 144) of second NGS tests, with 3.5% (5 of 144) of tests detecting a new BRCA2 alteration or MSI-high. A targeted therapy (poly (ADP-ribose) polymerase inhibitor or immunotherapy) was given after an actionable result on the second NGS test in 31.3% (5 of 16) of patients.

CONCLUSION

Repeat somatic NGS testing in men with prostate cancer is infrequently performed in practice and can identify new actionable alterations not present with initial testing, suggesting the utility of repeat molecular profiling with tissue or blood of men with metastatic castration-resistant prostate cancer to guide therapy choices.

Evolution of Precision Oncology, Personalized Medicine, and Molecular Tumor Boards

With multiple molecular targeted therapies available for patients with cancer that correspond to a specific genetic alteration, the selection of the best treatment is essential to ensure therapeutic efficacy. Molecular tumor boards (MTBs) play a key role in this process to deliver personalized medicine to patients with cancer in a multidisciplinary manner. Historically, personalized medicine has been offered to patients with advanced cancer, but the incorporation of molecular targeted therapies and immunotherapy into the perioperative setting requires clinicians to understand the role of the MTB. Evidence is accumulating to support feasibility and survival benefit in patients treated with matched therapy.

PARP Inhibitors in Metastatic Prostate Cancer: A Comprehensive Systematic Review and Meta-analysis of Existing Evidence

Poly (ADP-ribose) polymerase inhibitors (PARPi) represent an option in selected cases of metastatic castration-resistant prostate cancer (mCRPC). The aim of the present systematic review and meta-analysis is to evaluate the efficacy and safety of approved (Olaparib, Rucaparib) and investigational (Talazoparib, Niraparib, Veliparib) PARPi in mCRPC patients. Three databases were queried for studies analyzing oncological outcomes and adverse events of mCRPC patients receiving PARPi. Primary outcome was a PSA decline ≥ 50% from baseline. Secondary outcomes were objective response rate, progression-free survival (PFS), radiological PFS, overall survival (OS), conversion of circulating tumor cell count, and time to PSA progression. The number and rate of any grade adverse events (AEs), grade ≥ 3 AEs, and most common grade ≥ 3 AEs were registered. A subanalysis of outcomes per mutation type, prospective trials, and studies adopting combination therapies was performed. Overall, 31 studies were included in this systematic review, 28 of which are available for meta-analysis. The most frequently investigated drug was Olaparib. The most frequent mutation was BRCA2. A PSA decline rate of 43% (95% CI 0.32-0.54) was observed in the overall population. Mean OS was 15.9 (95% CI 12.9-19.0) months. In BRCA2 patients, PSA decline rate was 66% (95% CI 0.57-0.7) and OS 23.4 months (95% CI 22.8-24.1). Half of the patients suffered from grade 3 and 4 AEs (0.50 [95% CI 0.39-0.60]). Most common AEs were hematological, the most frequent being anemia (21.5%). PARP inhibitors represent a viable option for mCRPC patients. Current evidence suggests an increased effectiveness in homologous recombination repair (HRR) gene mutation carriers, especially BRCA2.

Expert Perspectives on Controversies in Metastatic Castration-Resistant Prostate Cancer Management: Narrative Review and Report of the First US Prostate Cancer Conference Part 2

Background

Management strategies for metastatic castration-resistant prostate cancer (mCRPC) have rapidly shifted in recent years. As novel imaging and therapeutic approaches have made their way to the clinic, providers are encountering increasingly challenging clinical scenarios, with limited guidance from the current literature.

Materials and Methods

The US Prostate Cancer Conference (USPCC) is a multidisciplinary meeting of prostate cancer experts intended to address the many challenges of prostate cancer management. At the first annual USPCC meeting, areas of controversy and consensus were identified during a 2-day meeting that included expert presentations, full-panel discussions, and postdiscussion responses to questions developed by the USPCC cochairs and session moderators.

Results

This narrative review covers the USPCC expert discussion and perspectives relevant to mCRPC, including neuroendocrine/aggressive-variant prostate cancer (NEPC/AVPC). Areas of broad agreement identified among USPCC experts include the benefits of poly (ADP-ribose) polymerase (PARP) inhibitors for patients with BRCA1/2 mutations, the use of radioligand therapy in patients with prostate-specific membrane antigen (PSMA)-positive mCRPC, and the need for clinical trials that address real-world clinical questions, including the performance of novel therapies when compared with modern standard-of-care treatment. Ongoing areas of controversy and uncertainty included the appropriateness of PARP inhibitors in patients with non-BRCA1/2 mutations, the optimal definition of PSMA positivity, and systemic therapies for patients with NEPC/AVPC after progression on platinum-based therapies.

Conclusions

The first annual USPCC meeting identified several areas of controversy in the management of mCRPC, highlighting the urgent need for clinical trials designed to facilitate treatment selection and sequencing in this heterogeneous disease state.

The cost-effectiveness of germline BRCA testing-guided olaparib treatment in metastatic castration resistant prostate cancer

BACKGROUND

Olaparib targets the DNA repair pathways and has revolutionized the management of metastatic castration resistant prostate cancer (mCRPC). Treatment with the drug should be guided by genetic testing; however, published economic evaluations did not consider olaparib and genetic testing as codependent technologies. This study aims to assess the cost-effectiveness of BRCA germline testing to inform olaparib treatment in mCRPC.

METHODS

We conducted a cost-utility analysis of germline BRCA testing-guided olaparib treatment compared to standard care without testing from an Australian health payer perspective. The analysis applied a decision tree to indicate the germline testing or no testing strategy. A Markov multi-state transition approach was used for patients within each strategy. The model had a time horizon of 5 years. Costs and outcomes were discounted at an annual rate of 5 percent. Decision uncertainty was characterized using probabilistic and scenario analyses.

RESULTS

Compared to standard care, BRCA testing-guided olaparib treatment was associated with an incremental cost of AU$7,841 and a gain of 0.06 quality-adjusted life-years (QALYs). The incremental cost-effectiveness ratio (ICER) was AU$143,613 per QALY. The probability of BRCA testing-guided treatment being cost effective at a willingness-to-pay threshold of AU$100,000 per QALY was around 2 percent; however, the likelihood for cost-effectiveness increased to 66 percent if the price of olaparib was reduced by 30 percent.

CONCLUSION

This is the first study to evaluate germline genetic testing and olaparib treatment as codependent technologies in mCRPC. Genetic testing-guided olaparib treatment may be cost-effective with significant discounts on olaparib pricing.

DNA Damage Response and Mismatch Repair Gene Defects in Advanced and Metastatic Prostate Cancer

Alterations in DNA damage response (DDR) and related genes are present in up to 25% of advanced prostate cancers (PCa). Most frequently altered genes are involved in the homologous recombination repair, the Fanconi anemia, and the mismatch repair pathways, and their deficiencies lead to a highly heterogeneous spectrum of DDR-deficient phenotypes. More than half of these alterations concern non- BRCA DDR genes. From a therapeutic perspective, poly-ADP-ribose polymerase inhibitors have demonstrated robust clinical efficacy in tumors with BRCA2 and BRCA1 alterations. Mismatch repair-deficient PCa, and a subset of CDK12-deficient PCa, are vulnerable to immune checkpoint inhibitors. Emerging data point to the efficacy of ATR inhibitors in PCa with ATM deficiencies. Still, therapeutic implications are insufficiently clarified for most of the non- BRCA DDR alterations, and no successful targeted treatment options have been established.

TALAPRO-3 clinical trial protocol: phase III study of talazoparib plus enzalutamide in metastatic castration-sensitive prostate cancer

Poly(ADP-ribose) polymerase inhibitors in combination with androgen-receptor signaling inhibitors are a promising therapeutic option for patients with metastatic castration-sensitive prostate cancer (mCSPC) and homologous recombination repair (HRR) gene alterations. Here, we describe the design and rationale of the multinational, phase III, TALAPRO-3 study comparing talazoparib plus enzalutamide versus placebo plus enzalutamide in patients with mCSPC and HRR gene alterations. The primary end point is investigator-assessed radiographic progression-free survival (rPFS) per RECIST 1.1 in soft tissue, or per PCWG3 criteria in bone. The TALAPRO-3 study will demonstrate whether the addition of talazoparib can improve the efficacy of enzalutamide as assessed by rPFS in patients with mCSPC and HRR gene alterations undergoing androgen deprivation therapy. Clinical Trial Registration:NCT04821622 (ClinicalTrials.gov) Registry Name: Study of Talazoparib With Enzalutamide in Men With DDR Gene Mutated mCSPC. Date of Registration: 29 March 2021.

Predictive and prognostic biomarkers in urological tumours

Advancements in cutting-edge molecular profiling techniques, such as next-generation sequencing and bioinformatic analytic tools, have allowed researchers to examine tumour biology in detail and stratify patients based on factors linked with clinical outcome and response to therapy. This manuscript highlights the most relevant prognostic and predictive biomarkers in kidney, bladder, prostate and testicular cancers with recognised impact in clinical practice. In bladder and prostate cancer, new genetic acquisitions concerning the biology of tumours have modified the therapeutic scenario and led to the approval of target directed therapies, increasing the quality of patient care. Thus, it has become of paramount importance to choose adequate molecular tests, i.e., FGFR screening for urothelial cancer and BRCA1-2 alterations for prostate cancer, to guide the treatment plan for patients. While no tissue or blood-based biomarkers are currently used in routine clinical practice for renal cell carcinoma and testicular cancers, the field is quickly expanding. In kidney tumours, gene expression signatures might be the key to identify patients who will respond better to immunotherapy or anti-angiogenic drugs. In testicular germ cell tumours, the use of microRNA has outperformed conventional serum biomarkers in the diagnosis of primary tumours, prediction of chemoresistance, follow-up monitoring, and relapse prediction.

Drivers of cancer metastasis - Arise early and remain present

Cancer and its metastases arise from mutations of genes, drivers that promote a tumor's growth. Analyses of driver events provide insights into cancer cell history and may lead to a better understanding of oncogenesis. We reviewed 27 metastatic research studies, including pan-cancer studies, individual cancer studies, and phylogenetic analyses, and summarized our current knowledge of metastatic drivers. All of the analyzed studies had a high level of consistency of driver mutations between primary tumors and metastasis, indicating that most drivers appear early in cancer progression and are maintained in metastatic cells. Additionally, we reviewed data from around 50,000 metastatic cancer patients and compiled a list of genes altered in metastatic lesions. We performed Gene Ontology analysis and confirmed that the most significantly enriched processes in metastatic lesions were the epigenetic regulation of gene expression, signal transduction, cell cycle, programmed cell death, DNA damage, hypoxia and EMT. In this review, we explore the most recent discoveries regarding genetic factors in the advancement of cancer, specifically those that drive metastasis.

TARGET: A Randomized, Noninferiority Trial of a Pretest, Patient-Driven Genetic Education Webtool Versus Genetic Counseling for Prostate Cancer Germline Testing

PURPOSE

Germline genetic testing (GT) is important for prostate cancer (PCA) management, clinical trial eligibility, and hereditary cancer risk. However, GT is underutilized and there is a shortage of genetic counselors. To address these gaps, a patient-driven, pretest genetic education webtool was designed and studied compared with traditional genetic counseling (GC) to inform strategies for expanding access to genetic services.

METHODS

Technology-enhanced acceleration of germline evaluation for therapy (TARGET) was a multicenter, noninferiority, randomized trial (ClinicalTrials.gov identifier: NCT04447703) comparing a nine-module patient-driven genetic education webtool versus pretest GC. Participants completed surveys measuring decisional conflict, satisfaction, and attitudes toward GT at baseline, after pretest education/counseling, and after GT result disclosure. The primary end point was noninferiority in reducing decisional conflict between webtool and GC using the validated Decisional Conflict Scale. Mixed-effects regression modeling was used to compare decisional conflict between groups. Participants opting for GT received a 51-gene panel, with results delivered to participants and their providers.

RESULTS

The analytic data set includes primary outcome data from 315 participants (GC [n = 162] and webtool [n = 153]). Mean difference in decisional conflict score changes between groups was -0.04 (one-sided 95% CI, -∞ to 2.54; P = .01), suggesting the patient-driven webtool was noninferior to GC. Overall, 145 (89.5%) GC and 120 (78.4%) in the webtool arm underwent GT, with pathogenic variants in 15.8% (8.7% in PCA genes). Satisfaction did not differ significantly between arms; knowledge of cancer genetics was higher but attitudes toward GT were less favorable in the webtool arm.

CONCLUSION

The results of the TARGET study support the use of patient-driven digital webtools for expanding access to pretest genetic education for PCA GT. Further studies to optimize patient experience and evaluate them in diverse patient populations are warranted.

Circulating tumor DNA and tissue complementarily detect genomic alterations in metastatic hormone-sensitive prostate cancer

The clinical utility of circulating tumor DNA (ctDNA) in hormone-sensitive prostate cancer (HSPC) remains inadequately elucidated. This study presents the largest real-world cohort to conduct a concordance analysis between ctDNA and tissue-based genomic profiling in HSPC patients. The findings reveal diminished ctDNA abundance in cases with low tumor burden and demonstrate an increased concordance rate between ctDNA and tissue along with the progression of disease burden. Notably, a substantial number of exclusive genomic alterations (GAs) were identified either in ctDNA or tissue in high-volume metastatic disease. Integrating tissue and ctDNA analysis identified specific gene alterations (BRCA1, BRCA2, CDK12, TP53, PTEN, or RB1) associated with a shorter time to the progression to castration-resistant prostate cancer (CRPC), with an escalated CRPC risk correlated with cumulative GAs. This multicenter, real-world investigation underscores the complementary role of ctDNA and tissue in detecting clinically pertinent GAs, highlighting their potential integration into clinical practice for advanced prostate cancer management.

Convergent evolution of BRCA2 reversion mutations under therapeutic pressure by PARP inhibition and platinum chemotherapy

Reversion mutations that restore wild-type function of the BRCA gene have been described as a key mechanism of resistance to Poly(ADP-ribose) polymerase (PARP) inhibitor therapy in BRCA-associated cancers. Here, we report a case of a patient with metastatic castration-resistant prostate cancer (mCRPC) with a germline BRCA2 mutation who developed acquired resistance to PARP inhibition. Extensive genomic interrogation of cell-free DNA (cfDNA) and tissue at baseline, post-progression, and postmortem revealed ten unique BRCA2 reversion mutations across ten sites. While several of the reversion mutations were private to a specific site, nine out of ten tumors contained at least one mutation, suggesting a powerful clonal selection for reversion mutations in the presence of therapeutic pressure by PARP inhibition. Variable cfDNA shed was seen across tumor sites, emphasizing a potential shortcoming of cfDNA monitoring for PARPi resistance. This report provides a genomic portrait of the temporal and spatial heterogeneity of prostate cancer under the selective pressure of a PARP inhibition and exposes limitations in the current strategies for detection of reversion mutations.

Precision Medicine in Castration-Resistant Prostate Cancer: Advances, Challenges, and the Landscape of PARPi Therapy-A Narrative Review

After recent approvals, poly-adenosine diphosphate [ADP]-ribose polymerase inhibitors (PARPis) have emerged as a frontline treatment for metastatic castration-resistant prostate cancer (mCRPC). Unlike their restricted use in breast or ovarian cancers, where approval is limited to those with BRCA1/2 alterations, PARPis in mCRPC are applied across a broader spectrum of genetic aberrations. Key findings from the phase III PROPEL trial suggest that PARPis' accessibility may broaden, even without mandatory testing. An increasing body of evidence underscores the importance of distinct alterations in homologous recombination repair (HRR) genes, revealing unique sensitivities to PARPis. Nonetheless, despite the initial effectiveness of PARPis in treating BRCA-mutated tumors, resistance to therapy is frequently encountered. This review aims to discuss patient stratification based on biomarkers and genetic signatures, offering insights into the nuances of first-line PARPis' efficacy in the intricate landscape of mCRPC.

Olaparib for the Treatment of Patients With Metastatic Castration-Resistant Prostate Cancer and Alterations in BRCA1 and/or BRCA2 in the PROfound Trial

Olaparib improved PFS and OS across subgroups of BRCA1/2mut #prostatecancer patients in the PROFOUND phase III trial.

Biomarker Testing Journey Among Patients with Advanced Solid Tumors and Treatment Patterns by Homologous Recombination Repair Status: A Clinico-Genomic Database Study

INTRODUCTION

Defects in the homologous recombination repair (HRR) pathway can include mutations in BRCA1 and BRCA2 (BRCAm) and other HRR genes (HRRm). These mutations are associated with a homologous recombination deficiency (HRD) phenotype. We evaluated testing journey and treatment patterns by BRCAm, HRRm, and HRD status in a real-world dataset.

METHODS

Deidentified data for patients who had undergone comprehensive genomic profiling using FoundationOne®CDx were collected through December 31, 2020, from a real-world multi-tumor clinico-genomic database (CGDB) capturing data from clinics in the United States. Patients eligible for inclusion in this analysis had a confirmed diagnosis with advanced or metastatic disease between January 1, 2018, and December 31, 2019, for 1 of 15 solid tumor types. Objectives were to evaluate patient treatment patterns by BRCAm, HRRm, and HRD status and to describe the timing of when (throughout disease course) comprehensive genomic profiling was performed.

RESULTS

Among 9457 patients included in the overall population with evaluable biomarker status, 7856 (83.1%) received ≥ 1 systemic therapy. Among the 7856 patients who received systemic therapy, 2324 (30.0%) underwent testing before first-line therapy, 4114 (52.4%) were tested after receiving first-line therapy and before receiving subsequent therapy (if any), 970 (12.3%) were tested after second-line therapy and before receiving subsequent therapy (if any), and 447 (5.7%) patients underwent testing after receiving third-line therapy. A higher proportion of patients with BRCAm, HRRm, or HRD-positive status were treated with poly(ADP-ribose) polymerase (PARP) inhibitors across all lines of therapy. There was no evidence of a meaningful difference in the proportion of patients who received other treatment (including chemotherapy and immunotherapy) by BRCAm, HRRm, or HRD status.

CONCLUSION

The majority of patients from this real-world dataset underwent FoundationOne®CDx testing after initiation of first-line treatment. Testing appeared to influence treatment patterns, with a higher proportion of patients with BRCAm, HRRm, and HRD-positive disease receiving PARP inhibitors.

PARP inhibitors for prostate cancer

Poly(ADP-ribose) polymerase (PARP) inhibitors have transformed the treatment landscape for patients with metastatic castration-resistant prostate cancer (mCRPC) and alterations in DNA damage response genes. This has also led to widespread use of genomic testing in all patients with mCRPC. The current review will give an overview of (1) the current understanding of the interplay between DNA damage response and PARP enzymes; (2) the clinical landscape of PARP inhibitors, including the combination of PARP inhibitors with other agents such as androgen-receptor signaling agents; (3) biomarkers related to PARP inhibitor response and resistance; and (4) considerations for interpreting genomic testing results and treating patients with PARP inhibitors.

PROMISE Registry: A prostate cancer registry of outcomes and germline mutations for improved survival and treatment effectiveness

BACKGROUND

Recently approved treatments and updates to genetic testing recommendations for prostate cancer have created a need for correlated analyses of patient outcomes data via germline genetic mutation status. Genetic registries address these gaps by identifying candidates for recently approved targeted treatments, expanding clinical trial data examining specific gene mutations, and understanding effects of targeted treatments in the real-world setting.

METHODS

The PROMISE Registry is a 20-year (5-year recruitment, 15-year follow-up), US-wide, prospective genetic registry for prostate cancer patients. Five thousand patients will be screened through an online at-home germline testing to identify and enroll 500 patients with germline mutations, including: pathogenic or likely pathogenic variants and variants of uncertain significance in genes of interest. Patients will be followed for 15 years and clinical data with real time patient reported outcomes will be collected. Eligible patients will enter long-term follow-up (6-month PRO surveys and medical record retrieval). As a virtual study with patient self-enrollment, the PROMISE Registry may fill gaps in genetics services in underserved areas and for patients within sufficient insurance coverage.

RESULTS

The PROMISE Registry opened in May 2021. 2114 patients have enrolled to date across 48 US states and 23 recruiting sites. 202 patients have met criteria for long-term follow-up. PROMISE is on target with the study's goal of 5000 patients screened and 500 patients eligible for long-term follow-up by 2026.

CONCLUSIONS

The PROMISE Registry is a novel, prospective, germline registry that will collect long-term patient outcomes data to address current gaps in understanding resulting from recently FDA-approved treatments and updates to genetic testing recommendations for prostate cancer. Through inclusion of a broad nationwide sample, including underserved patients and those unaffiliated with major academic centers, the PROMISE Registry aims to provide access to germline genetic testing and to collect data to understand disease characteristics and treatment responses across the disease spectrum for prostate cancer with rare germline genetic variants.

The Molecular, Immunologic, and Clinicodemographic Landscape of MYC-Amplified Advanced Prostate Cancer

BACKGROUND

MYC is a commonly amplified, potentially targetable gene in prostate cancer (PCa). We sought to define the molecular, immunologic, and clinicodemographic landscape of MYC amplification (MYCamp) in advanced PCa to establish a rationale for personalized treatment combinations.

METHODS

Hybrid capture-based comprehensive genomic profiling (CGP) was performed on PCa tumor samples. MYCamp = copy number ≥6 (CN). Patients treated between January 2011 and December 2020 were selected from a nationwide deidentified (280 clinics) EHR-derived clinicogenomic database (CGDB).

RESULTS

Of 12,528 hormone-sensitive and castrate-resistant (CRPC) samples, MYCamp was detected in 10.6% (median CN = 8). MYCamp was more frequent in men with African versus European ancestry (12.9% vs. 10.2% P = .002), in metastatic vs. primary tissue (15.7% vs. 6.2% P < .001), and enriched in metastatic liver lesions (20.2%), but inversely associated with high microsatellite-instability (0.8% vs. 2.4%, P < .001). MYC CN≥15 was associated with PD-L1 expression (26.1% vs. 9.8%, P = .025). Amplification of AR, RAD21, LYN, CCND1, ZNF703, FGF3/4/19, and FGFR1 was enriched in MYCamp vs. MYCwt (all P < .001). In liquid samples with tumor fraction [TF]>0, MYCamp was detected in 2.0% (28/1,402), and 4.5% (20/445) with TF>20%. In the CGDB, (67 MYCamp and 658 MYCwt), patients received similar treatments; most received hormone therapies (35.8% MYCamp vs. 31.5% MYCwt) or chemotherapy (37.3% MYCamp vs. 27.7% MYCwt) as first therapy after CGP report.

CONCLUSION

MYCamp defines a biologically distinct subset of PCa patients and is characterized with multiple proxies of advanced disease. These data suggest that MYCamp may be prognostic; independent cohorts are needed to validate these findings.

Blood-based liquid biopsy in advanced prostate cancer

Prostate cancer is characterized by several genetic alterations which could impact prognosis and therapeutic decisions in the advanced disease. Tissue biopsy is still considered the gold standard approach for molecular characterization in prostate cancer, but it has several limitations, including the possibility of insufficient/inadequate tumor tissue to be analyzed. Blood-based liquid biopsy is a non-invasive method to investigate tumor cell derivatives in the bloodstream, being a valid alternative to tissue biopsy for molecular characterization but also for predictive and/or prognostic purposes. In this review, we analyze the most relevant evidence in this field, focusing on clinically relevant targets such as HRD genetic alterations and also focusing on the differences between tissue and liquid biopsy in light of the data from the latest clinical trials.

Gender-Specific Genetic Predisposition to Breast Cancer: BRCA Genes and Beyond

Among neoplastic diseases, breast cancer (BC) is one of the most influenced by gender. Despite common misconceptions associating BC as a women-only disease, BC can also occur in men. Additionally, transgender individuals may also experience BC. Genetic risk factors play a relevant role in BC predisposition, with important implications in precision prevention and treatment. The genetic architecture of BC susceptibility is similar in women and men, with high-, moderate-, and low-penetrance risk variants; however, some sex-specific features have emerged. Inherited high-penetrance pathogenic variants (PVs) in BRCA1 and BRCA2 genes are the strongest BC genetic risk factor. BRCA1 and BRCA2 PVs are more commonly associated with increased risk of female and male BC, respectively. Notably, BRCA-associated BCs are characterized by sex-specific pathologic features. Recently, next-generation sequencing technologies have helped to provide more insights on the role of moderate-penetrance BC risk variants, particularly in PALB2, CHEK2, and ATM genes, while international collaborative genome-wide association studies have contributed evidence on common low-penetrance BC risk variants, on their combined effect in polygenic models, and on their role as risk modulators in BRCA1/2 PV carriers. Overall, all these studies suggested that the genetic basis of male BC, although similar, may differ from female BC. Evaluating the genetic component of male BC as a distinct entity from female BC is the first step to improve both personalized risk assessment and therapeutic choices of patients of both sexes in order to reach gender equality in BC care. In this review, we summarize the latest research in the field of BC genetic predisposition with a particular focus on similarities and differences in male and female BC, and we also discuss the implications, challenges, and open issues that surround the establishment of a gender-oriented clinical management for BC.

How to Integrate Prostate Cancer Biomarkers in Urology Clinical Practice: An Update

Nowadays, the management of prostate cancer has become more and more challenging due to the increasing number of available treatment options, therapeutic agents, and our understanding of its carcinogenesis and disease progression. Moreover, currently available risk stratification systems used to facilitate clinical decision-making have limitations, particularly in providing a personalized and patient-centered management strategy. Although prognosis and prostate cancer-specific survival have improved in recent years, the heterogenous behavior of the disease among patients included in the same risk prognostic group negatively impacts not only our clinical decision-making but also oncological outcomes, irrespective of the treatment strategy. Several biomarkers, along with available tests, have been developed to help clinicians in difficult decision-making scenarios and guide management strategies. In this review article, we focus on the scientific evidence that supports the clinical use of several biomarkers considered by professional urological societies (and included in uro-oncological guidelines) in the diagnosis process and specific difficult management strategies for clinically localized or advanced prostate cancer.

Development of PARP inhibitors in advanced prostate cancer

The relatively high prevalence of alterations in the homologous recombination repair (HRR) pathway described in advanced prostate cancer provides a unique opportunity to develop therapeutic strategies that take advantage of the decreased tumor ability to repair DNA damage. Poly ADP-ribose polymerase (PARP) inhibitors have been demonstrated to improve the outcomes of metastatic castration-resistant prostate cancer (mCRPC) patients with HRR defects, particularly in those with BRCA1/2 alterations. To expand the benefit of PARPi to patients without detectable HRR alterations, multiple studies are addressing potential synergies between PARP inhibition (PARPi) and androgen receptor pathway inhibitors (ARSi), radiation, radioligand therapy, chemotherapy, or immunotherapy, and these strategies are also being evaluated in the hormone-sensitive setting. In this review, we summarize the development of PARPi in prostate cancer, the potential synergies, and combinations being investigated as well as the future directions of PARPi for the management of the disease.

A Practical Approach for Targeting Structural Variants Genome-wide in Plasma Cell-free DNA

Plasma cell-free DNA (cfDNA) is a promising source of gene mutations for cancer detection by liquid biopsy. However, no current tests interrogate chromosomal structural variants (SVs) genome-wide. Here, we report a simple molecular and sequencing workflow called Genome-wide Analysis of Palindrome Formation (GAPF-seq) to probe DNA palindromes, a type of SV that often demarcates gene amplification. With low-throughput next-generation sequencing and automated machine learning, tumor DNA showed skewed chromosomal distributions of high-coverage 1-kb bins (HCBs), which differentiated 39 breast tumors from matched normal DNA with an average Area Under the Curve (AUC) of 0.9819. A proof-of-concept liquid biopsy study using cfDNA from prostate cancer patients and healthy individuals yielded an average AUC of 0.965. HCBs on the X chromosome emerged as a determinant feature and were associated with androgen receptor gene amplification. As a novel agnostic liquid biopsy approach, GAPF-seq could fill the technological gap offering unique cancer-specific SV profiles.