Analysis of the Prevalence of Microsatellite Instability in Prostate Cancer and Response to Immune Checkpoint Blockade

Discovery and development of steroidal enzyme inhibitors as anti-cancer drugs: state-of-the-art and future perspectives

Steroidal compounds have emerged as effective therapeutic agents in oncology. Beyond natural-occurring and synthetic steroids that act as cytotoxic anti-tumoral agents, steroidal derivatives can be designed to mime the endogenous substrates of key metabolic enzymes in steroidogenesis, thus reducing the circulating levels of relevant oestrogenic and androgenic hormones responsible for cancer survival and proliferation. Therefore, enzyme inhibition represents an intriguing endocrine approach for the treatment of hormone-dependent tumours, such as breast and prostate cancer, with well-known approved drugs and several pre-clinical and clinical candidates under investigation. This review summarises the key advancements over the past decade (2014-2024) in the development of steroidal enzyme inhibitors endowed with anticancer activity, illustrating their mechanisms of action, therapeutic potential, drug design approaches, and current clinical applications. Furthermore, we discuss challenges related to drug resistance, off-target effects, and future strategies to optimise their efficacy in oncology.

Biomarkers in metastatic castration-resistant prostate cancer for efficiency of immune checkpoint inhibitors

Almost all patients with prostate cancer progress to metastatic castration-resistant prostate cancer (mCRPC) despite initial responses. In cases where traditional first-line treatments prove ineffective, the potential of immune checkpoint blockade (ICB) therapy emerges as a promising approach for managing mCRPC. However, while immune checkpoint inhibitor monotherapy or combination therapy targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) and/or programmed cell death-1 (PD-1)/PD-1 ligand 1 (PD-L1) axis has been regarded as the standard therapy in many solid tumours, mCRPC as 'cold' tumours are considered to be relatively resistant to ICB treatment. Encouragingly, recent evidence suggests that ICB therapy may be particularly beneficial in specific subgroups of patients with high PD-L1 tumour expression, high tumour mutational burden or high tumour microsatellite instability/mismatch repair deficiency. Better understanding of these predictive biomarkers could screen which patients are most likely to benefit. This review article examines biomarkers for screening patients potentially effective in immune checkpoint inhibitor therapy.

State of the Art: Personalizing Treatment for Patients With Metastatic Castration-Resistant Prostate Cancer

Until recently, the treatment of metastatic castration-resistant prostate cancer (mCRPC) relied exclusively on hormonal therapies and taxane chemotherapy. The advent of modern molecular profiling methods applied in the clinic, namely, next-generation sequencing and advanced positron emission tomography (PET) imaging, has allowed for the development of biomarker-driven therapeutics including anti-PD-L1 therapy for microsatellite instability-high or tumor mutation burden-high disease, poly(ADP-ribose) polymerase (PARP) inhibitors for patients with DNA damage repair mutations, and lutetium 177 vipivotide tetraxetan (177Lu-PSMA-617) for patients with prostate-specific membrane antigen (PSMA) PET-avid disease. While these targeted therapies have improved outcomes, there is an opportunity to refine biomarkers to optimize patient selection, understand resistance, and develop novel combination strategies. In addition, studies in the laboratory and in patient-derived samples have shown that a subset of mCRPC tumors lose expression of common prostate cancer markers such as prostate-specific antigen and PSMA because of lineage plasticity and the development of non-androgen receptor (AR)-driven disease. Non-AR-driven prostate cancer has been associated with aggressive behavior and poor prognosis, including in some cases histologic transformation to a poorly differentiated neuroendocrine prostate cancer (NEPC). The clinical management of NEPC typically follows the treatment paradigm for small cell lung cancer and increasingly relies on genomic and phenotypic characterization of disease, including loss of tumor suppressors and expression of cell surface markers such as DLL3. Therefore, both genomic subtyping and phenotypic subtyping are important to consider and can guide the clinical management of patients with advanced prostate cancer.

Inhibition of PIM Kinase in Tumor-Associated Macrophages Suppresses Inflammasome Activation and Sensitizes Prostate Cancer to Immunotherapy

Immune checkpoint inhibitors (ICI) have changed the treatment paradigm for many cancers but have not shown benefit in prostate cancer. Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. In this study, we identify the proviral integration site for Moloney murine leukemia virus (PIM) kinases as regulators of inflammasome activation in tumor-associated macrophages (TAM). The analysis of clinical data from a cohort of patients with treatment-naïve, hormone-responsive prostate cancer revealed that tumors from patients with high PIM1/2/3 displayed an immunosuppressive tumor microenvironment characterized by high inflammation and a high density of repressive immune cells, most notably TAMs. Macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of prostate cancer. Transcriptional analyses indicated that eliminating PIM from macrophages enhanced the adaptive immune response and increased cytotoxic immune cells. Combined treatment with PIM inhibitors and ICIs synergistically reduced tumor growth. Immune profiling revealed that PIM inhibitors sensitized prostate cancer tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Our data implicate macrophage PIM as a driver of inflammation that limits ICI potency and provide preclinical evidence that PIM inhibitors are an effective strategy to improve the ICI efficacy in prostate cancer.

Genomic and transcriptomic sequencing in prostate cancer

PURPOSE OF REVIEW

Genomic and transcriptomic sequencing technologies have revolutionized our ability to characterize prostate cancer at the molecular level. The underlying premise of next-generation sequencing technologies and their current and evolving applications in prostate cancer management are provided in the review.

RECENT FINDINGS

Improved methodologies are allowing timely sequencing of the coding regions or both the coding and noncoding regions of the genome to help identify potential mutations and structural variations in the prostate cancer genome, some of which are currently also targetable therapeutically. DNA microarray- based differential gene expression has been supplanted by RNA sequencing (RNA-seq), which not only allows for more accurate quantitation but also nucleotide-level resolution to investigate the entire transcriptome, including alternative gene spliced transcripts and noncoding RNA transcripts, whose full clinical implications have yet to be fully understood and realized. Gene classifier platforms that predict risk of recurrence or metastasis are being incorporated into prostate cancer management algorithms. In the appropriate clinical context, not only somatic but also germline mutation testing is being recommended.

SUMMARY

Continued clinical integration of sequencing technologies and ongoing research will lead to improved understanding of prostate cancer biology and prostate cancer treatment.

Prevalence of Mismatch Repair Deficiency in Primary Prostate Cancer in a Large Prospective Cohort

PURPOSE

Mismatch repair (MMR) deficiency and microsatellite instability are predictive biomarkers for immunotherapy response. The best approach to identify patients with such tumors is unclear in prostate cancer.

EXPERIMENTAL DESIGN

This study included 1,016 men diagnosed with primary prostate cancer during prospective follow-up of the Health Professionals Follow-up Study and Physicians' Health Study. The highest-grade/index lesions from radical prostatectomy (95%) or transurethral resections of the prostate were mounted on tissue microarrays. Scoring of immunohistochemistry for the MMR proteins MLH1, MSH2, MSH6, and PMS2 required a nontumor internal positive control for designating deficiency. Validation was done on full sections and with PCR-based quantification of microsatellite repeats.

RESULTS

Tumor stage was predominantly pathologically localized with a full distribution of Gleason scores. MMR tumor scoring could be performed with available internal positive control tissue in 75% to 90% of cases, depending on the MMR protein. Of the 903 tumors evaluable for MSH2 protein loss, 4 tumors had loss of MSH2 (prevalence, 0.4%; 95% confidence interval, 0.2%-1.1%), and 3 of 708 evaluable tumors had concomitant loss of MSH6 (prevalence, 0.4%; 95% confidence interval, 0.1%-1.2%). No tumor had loss of MLH1 or PMS2. The four MMR-deficient cases had higher Gleason scores, and three had non-zero microsatellite repeats.

CONCLUSIONS

In this nationwide prospective study, MMR deficiency was rare in primary, surgically treated prostate cancer. The low prevalence and the need for an internal positive control for this assay are feasibility concerns for unselected routine immunohistochemistry-based screening for MMR deficiency on limited tissue specimens, such as prostate biopsies.

Epidemiology, pathogenesis, biology and evolving management of MSI-H/dMMR cancers

Deficiency in DNA mismatch repair (dMMR) is a common pathway of carcinogenesis across different tumour types and confers a characteristic microsatellite instability-high (MSI-H) molecular phenotype. The prevalence of the MSI-H/dMMR phenotype is highest in endometrial and colorectal cancers, and this phenotype is associated with a distinct tumour biology, prognosis and responsiveness to various anticancer treatments. In a minority of patients, MSI-H/dMMR cancers result from an inherited pathogenic variant in the context of Lynch syndrome, which has important implications for familial genetic screening. Whether these hereditary cancers have a different biology and clinical behaviour to their sporadic counterparts remains uncertain. Interest in this tumour molecular subtype has increased following the discovery of the high sensitivity of metastatic MSI-H/dMMR cancers to immune-checkpoint inhibitors (ICIs) in a histology-agnostic manner, which reflects the genomic hypermutation resulting from dMMR that renders these tumours highly immunogenic and immune infiltrated. This vulnerability is now also being exploited in early stage disease settings. Despite this common biological foundation, different MSI-H/dMMR cancers have histotype-specific features that correspond to their particular cell or tissue of origin, which might be associated with differences in prognosis and sensitivity to ICIs. In this Review, we provide an overview of the epidemiology, biology, pathogenesis, clinical diagnosis and treatment of MSI-H/dMMR tumours as a histology-agnostic cancer phenomenon. We also highlight peculiarities associated with specific pathogenetic alterations and histologies of MSI-H/dMMR tumours.

Deciphering the mechanisms of PARP inhibitor resistance in prostate cancer: Implications for precision medicine

Prostate cancer is a leading malignancy among men. While early-stage prostate cancer can be effectively managed, metastatic prostate cancer remains incurable, with a median survival of 3-5 years. The primary treatment for advanced prostate cancer is androgen deprivation therapy (ADT), but resistance to ADT often leads to castrationresistant prostate cancer (CRPC), presenting a significant therapeutic challenge. The advent of precision medicine has introduced promising new treatments, including PARP inhibitors (PARPi), which target defects in DNA repair mechanisms in cancer cells. PARPi have shown efficacy in treating advanced prostate cancer, especially in patients with metastatic CRPC (mCRPC) harboring homologous recombination (HR)-associated gene mutations. Despite these advancements, resistance to PARPi remains a critical issue. Here, we explored the primary mechanisms of PARPi resistance in prostate cancer. Key resistance mechanisms include homologous recombination recovery through reverse mutations in BRCA genes, BRCA promoter demethylation, and non-degradation of mutated BRCA proteins. The tumor microenvironment and overactivation of the base excision repair pathway also play significant roles in bypassing PARPi-induced synthetic lethality. In addition, we explored the clinical implications and therapeutic strategies to overcome resistance,emphasizing the need for precision medicine approaches. Our findings highlight the need for comprehensive strategies to improve PARPi sensitivity and effectiveness,ultimately aiming to extend patient survival and improve the quality of life for those with advanced prostate cancer. As our understanding of PARPi resistance evolves, more diverse and effective individualized treatment regimens will emerge.

Immunotherapy in Prostate Cancer: From a "Cold" Tumor to a "Hot" Prospect

Immunotherapy has shown limited efficacy in prostate cancer, largely due to low tumor immunogenicity, sparse tumor-infiltrating lymphocytes, and a suppressive microenvironment. Recent therapeutic strategies aim to boost immune responses and counteract immunosuppressive factors through interventions such as immune checkpoint inhibitors, immunogenic cell death-inducing therapies, and the targeted blockade of pathways like that of transforming growth factor-β. Vaccine-based approaches, potent immune adjuvants, and engineered chimeric antigen receptor (CAR) T cells are also being investigated to overcome local immune inhibitory signals. Advancements in imaging, multi-omic profiling, and liquid biopsies offer promising avenues for real-time monitoring, better patient selection, and precision treatment. This review provides an overview of the key immunosuppressive features of prostate cancer, current immunotherapeutic modalities, and emerging strategies to transform "cold" tumors into more responsive "hot" targets. By integrating these approaches, we may achieve more durable clinical benefits for patients with advanced or metastatic prostate cancer.

Whole genome sequencing of 378 prostate cancer metastases reveals tissue selectivity for mismatch deficiency with potential therapeutic implications

BACKGROUND

Survival of patients with metastatic castration-resistant prostate cancer (mCRPC) depends on the site of metastatic dissemination.

METHODS

Patients with mCRPC were prospectively included in the CPCT-02 metastatic site biopsy study. We evaluated whole genome sequencing (WGS) of 378 mCRPC metastases to understand the genetic traits that affect metastatic site distribution.

RESULTS

Our findings revealed that RB1, PIK3CA, JAK1, RNF43, and TP53 mutations are the most frequent genetic determinants associated with site selectivity for metastatic outgrowth. Furthermore, we explored mutations in the non-coding genome and found that androgen receptor (AR) chromatin binding sites implicated in metastatic prostate cancer differ in mutation frequencies between metastatic sites, converging on pathways that impact DNA repair. Notably, liver and visceral metastases have a higher tumor mutational load (TML) than bone and lymph node metastases, independent of genetic traits associated with neuroendocrine differentiation. We found that TML is strongly associated with DNA mismatch repair (MMR)-deficiency features in these organs.

CONCLUSIONS

Our results revealed gene mutations that are significantly associated with metastatic site selectivity and that frequencies of non-coding mutations at AR chromatin binding sites differ between metastatic sites. Immunotherapeutics are thus far unsuccessful in unselected mCRPC patients. We found a higher TML in liver and visceral metastases compared to bone and lymph node metastases. As immunotherapeutics response is associated with mutational burden, these findings may assist in selecting mCRPC patients for immunotherapy treatment based on organs affected by metastatic disease.

TRIAL REGISTRATION NUMBER

NCT01855477.

Distinct genomic features and mutational signatures of nucleotide excision repair and mismatch repair in thymoma

Thymoma is a rare malignancy with an unclear etiology of occurrence and development. We observed a higher incidence of thymoma in the Taiwanese population compared to other Western populations, suggesting the existence of different genomic features. Since most genomic studies are based on Western populations, we aimed to characterize the genomic profile of the Taiwanese population and compare it to the TCGA cohort in this study. We analyzed the genome of 47 thymoma patients using the Tumor Mutational Burden Panel to discover the genetic profile of the Taiwanese population. We also characterized the mutational signatures of these samples. Additionally, we leveraged RNA seq to estimate the gene expression profile and explored the featured pathways of thymoma in the Taiwanese population through gene set enrichment analysis.We identified several frequently mutated genes related to transcription, such as FAT1, KMT2D, and ZFHX3, as well as consensus mutational signatures associated with nucleotide excision repair (NER) and mismatch repair (MMR) deficiency. Our study also revealed increased activity of NER and MMR functions in our study cohort. Upon comparison with the TCGA cohort, we found dramatic differences in the most frequently mutated genes and mutational profiles between the Taiwanese and TCGA cohorts. Furthermore, we identified mismatch repair deficiency as a Taiwanese population-specific mutational signature with higher activity. These results highlight the distinct genomic background and molecular mechanisms of thymoma in the Taiwanese population, which may contribute to the development of new diagnostic and therapeutic strategies in the future.

Defined cellular reprogramming of androgen receptor-active prostate cancer to neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) arises primarily through neuroendocrine transdifferentiation (NEtD) as an adaptive mechanism of therapeutic resistance. Models to define the functional effects of putative drivers of this process on androgen receptor (AR) signaling and NE cancer lineage programs are lacking. We adapted a genetically defined strategy from the field of cellular reprogramming to directly convert AR-active prostate cancer (ARPC) to AR-independent NEPC using candidate factors. We delineated critical roles of the pioneer factors ASCL1 and NeuroD1 in NEtD and uncovered their abilities to silence AR expression and signaling by remodeling chromatin at the somatically acquired AR enhancer and global AR binding sites with enhancer activity. We also elucidated the dynamic temporal changes in the transcriptomic and epigenomic landscapes of cells undergoing acute lineage conversion from ARPC to NEPC which should inform future therapeutic development. Further, we distinguished the activities of ASCL1 and NeuroD1 from the inactivation of RE-1 silencing transcription factor (REST), a master suppressor of a major neuronal gene program, in establishing a NEPC lineage state and in modulating the expression of genes associated with major histocompatibility complex class I (MHC I) antigen processing and presentation. These findings provide important, clinically relevant insights into the biological processes driving NEtD of prostate cancer.

Recent advances in basic research on prostate cancer: Where we are heading?

In the over 80 years since androgens were found to play a pivotal role in prostate cancer (PCa) progression, androgen deprivation therapy (ADT) has been a cornerstone in treating advanced PCa. Castration-resistant PCa persists, however, with some of these tumors evolving to androgen receptor (AR)-independent forms like neuroendocrine PCa. The development of novel diagnostic and therapeutic approaches to PCa is therefore crucial. This review provides an overview of recent basic research in PCa, focusing on two main areas: PCa cells and their tumor microenvironments. The first section describes current knowledge on the intricate mechanisms of AR signaling pathways, emphasizing the roles of coactivators and chromatin state alterations in gene regulation. Genomic analyses have revealed recurrent mutations and copy number alterations critical for precision medicine. Liquid biopsy has become a promising tool for real-time tumor monitoring, identifying genetic alterations in circulating-tumor DNA or extracellular vesicles. The second section describes the tumor microenvironment of PCa, highlighting its immunosuppressive landscape and the potential of combining ADT with immunotherapy. Advanced techniques, including single-cell RNA sequencing and spatial transcriptomics offer insights into cellular heterogeneity and interactions within the tumor microenvironment, paving the way for novel therapeutic strategies. Integration of these diverse research areas will provide a comprehensive understanding of the current state and future directions of PCa research, underscoring the importance of personalized medicine and the dynamic nature of cancer treatment strategies.

Improved prognosis of de novo metastatic prostate cancer after an introduction of life-prolonging agents for castration-resistant prostate cancer

BACKGROUND

In Japan, since 2014, new treatments such as androgen receptor signaling inhibitors and cabazitaxel have become applicable for metastatic castration-resistant prostate cancer (mCRPC), leading to dramatic changes in treatment options.

OBJECTIVE

This study aims to evaluate the impact of recent advancements in treatment options on the overall survival (OS) of patients diagnosed with de novo metastatic castration-sensitive prostate cancer (mCSPC) in Japan.

METHODS

A retrospective analysis was conducted on 2450 Japanese men diagnosed with de novo mCSPC between 2008 and 2018. Patients were stratified into two groups based on the period of diagnosis: an earlier period (2008-2013) and a later period (2014-2018). OS was compared between earlier and later periods using Kaplan-Meier analysis in total and propensity score matched subpopulation as well as risk-stratified subgroups.

RESULTS

Patients diagnosed in the later period exhibited significantly improved OS compared to those diagnosed in the earlier period. The risk score, calculated based on ISUP grade group, LDH levels, and ALP levels, was a poor prognostic factor. In the later period, compared to the earlier period, there was no improvement in OS in the favorable-risk group, but a significant improvement was observed in the poor-risk group.

CONCLUSION

It was suggested that the introduction of novel androgen receptor signaling inhibitors and chemotherapy treatment regimens since 2014 has led to improved survival outcomes for patients with de novo mCSPC, particularly those with poor-risk profiles. The findings highlight the impact of recent advancements in treatment on the prognosis of patients with metastatic prostate cancer in Japan.

Deciphering Complexity: The Molecular Landscape of Castration-Resistant Prostate Cancer

Despite improvements in diagnosis and treatment approaches, prostate cancer (PC) remains a leading cause of cancer-related death in men. PC progresses through various stages, mostly driven by androgen receptor signaling. However, after androgen deprivation therapies, in a significant portion of patients, several different molecular mechanisms contribute to the development of castration resistance. Delving deeply into the molecular landscape of castration-resistant PC, grasping the selective pressures exerted by therapies, and understanding the drivers of lineage plasticity is pivotal to prevent progression. Targeting genetic and epigenetic alterations that drive this transition will guide clinical management strategies and possibly prevent and/or treat lethal disease.

The impact of the number of prior androgen receptor pathway inhibitors before cabazitaxel treatment in patients with metastatic castration-resistant prostate cancer

OBJECTIVE

Cabazitaxel (CAZ) has been shown to prolong overall survival (OS) in patients with metastatic castration-resistant prostate cancer (mCRPC) following docetaxel treatment. However, the impact of the number of prior androgen receptor pathway inhibitors (ARPIs) on CAZ efficacy remains unclear. This study aimed to analyze the effectiveness of CAZ based on the number of prior ARPIs administered before CAZ treatment.

METHODS

A retrospective review was conducted on mCRPC patients who received CAZ. The differences in CAZ efficacy based on the number of prior ARPIs were evaluated and prognostic factors for prostate-specific antigen (PSA) progression-free survival (PFS) and OS were analyzed.

RESULTS

A total of 59 patients were categorized into three groups: 12 patients with no prior ARPI, 26 with one prior ARPI, and 21 with two or more prior ARPIs. The median number of CAZ cycles and relative dose intensity were 5% and 60%, respectively. No significant differences were observed in PSA response or PFS among the three groups. Although OS from the first CAZ administration did not significantly differ among the groups, the OS from mCRPC diagnosis was shorter in the group with no prior ARPI. Multivariate analysis identified a time to mCRPC diagnosis of less than 11 months and low serum hemoglobin levels before CAZ administration as significant prognostic factors of poor OS following CAZ treatment.

CONCLUSIONS

PSA response, PFS, and OS after CAZ administration did not significantly differ based on the number of prior ARPIs. CAZ efficacy appears consistent regardless of the number of prior ARPI sequences.

Overcoming drug resistance in castrate-resistant prostate cancer: current mechanisms and emerging therapeutic approaches

Metastatic castration-resistant prostate cancer (mCRPC) is driven by a complex network of resistance mechanisms against standard-of-care therapies, resulting in poor long-term outcomes. This review offers a uniquely comprehensive and integrative perspective on these resistance pathways, systematically examining both androgen receptor (AR)-dependent factors (including AR overexpression, point mutations, glucocorticoid receptor signaling, splice variants, post-translational modifications, altered coregulators, and intratumoral hormone biosynthesis) and AR-independent pathways (such as neuroendocrine differentiation, lineage plasticity, and alternative growth factor signaling). We also highlight resistance mechanisms influencing immunotherapy, chemotherapy, radiopharmaceutical therapy and targeted therapy. By synthesizing emerging insights across these domains, this review not only clarifies the underlying biology of mCRPC resistance but also identifies key leverage points for more effective interventions. Building on this foundation, we propose a forward-looking framework for overcoming mCRPC drug resistance, emphasizing the importance of biomarker-guided patient selection, combination strategies that simultaneously target multiple resistance mechanisms, and novel therapies under investigation. These recommendations are intended to guide future clinical trial designs and research priorities that move beyond incremental improvements. Ultimately, this comprehensive synthesis aims to serve as a resource for clinicians and researchers to accelerate the development of durable, precision-based treatment strategies in mCRPC.

Novel Intraprostatic Magnetic Resonance-Guided Implantation of Multidrug-Eluting Microdevice for Testing of Systemic Therapy Agents In Situ: Proof of Concept in Intermediate-Risk and High-Risk Prostate Cancer

PURPOSE

The purpose of this study was to assess safety and feasibility of percutaneous magnetic resonance-guided placement of an implantable microdevice (IMD) to evaluate in situ intratumor response to multiple pharmacologic agents in men with intermediate-risk and high-risk localized prostate cancer.

MATERIALS AND METHODS

Biocompatible IMDs measuring 750 µm in diameter and 5 mm in length were prepared with 20 reservoirs containing candidate drug and drug combinations including second-generation androgen inhibitors, PARP inhibitors, PD-1 inhibitors, and conventional chemotherapy. Men with intermediate-risk or high-risk localized prostate cancer and MRI-visible lesions were enrolled. Up to 4 IMDs were placed using a transperineal approach into MRI-visible tumors 2 days before planned radical prostatectomy. After radical prostatectomy, the IMDs and a small segment of surrounding tumor tissue were removed and sectioned, stained, and analyzed for tissue drug response by a variety of pharmacodynamic markers.

RESULTS

Fourteen patients were enrolled: 7 (50%) with intermediate-risk and 7 (50%) with high-risk localized prostate cancer. A total of 53 IMDs were implanted (mean 3.8 per patient), and 49 IMDs (92%) were successfully retrieved. All men underwent uncomplicated robotic-assisted radical prostatectomy and bilateral pelvic lymph node dissection 2 days after IMD placement. There were no severe adverse events. Pathological examination of the tissues adjacent to the IMDs demonstrated differential drug response within patients and between patients. Limitations include small sample size.

CONCLUSIONS

A multidrug IMD can be safely placed percutaneously into MRI-visible lesions before radical prostatectomy, enabling assessment of tumor-specific local response to multiple agents simultaneously within the tumor's normal stromal environment to guide targeted systemic therapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04399876.

Safety and Efficacy of Neoadjuvant Docetaxel and Radiotherapy in Localized High-Risk Prostate Cancer: Results From a Prospective Pilot Study

OBJECTIVES

Approximately 15% of patients with localized prostate cancer are at high risk for disease recurrence. Many clinical trials have evaluated the impact of neoadjuvant therapy before radical prostatectomy with mixed results (NCT00321698).

METHODS

This phase I/II clinical trial evaluated the tolerability and preliminary efficacy of neoadjuvant radiation therapy and docetaxel before prostatectomy in 25 men with high-risk prostate cancer. The treatment regimen included 45 Gy radiotherapy in 25 fractions to the prostate and seminal vesicles over 5 weeks, along with weekly dose-escalated docetaxel up to 30 mg/m², followed by prostatectomy and bilateral lymph node dissection. The primary endpoint was the rate of pathologic complete response (pCR). Secondary endpoints included adverse events, symptom and quality of life measures, and prostate-specific antigen metrics.

RESULTS

All 25 patients completed the planned treatment. The primary endpoint of pCR was not achieved. Lymphopenia was the most common grade 3 or higher toxicity, with no grade 3 or higher genitourinary or gastrointestinal toxicities observed. With a median follow-up of 11.6 years, the 10-year biochemical recurrence-free survival was 60%, and distant metastasis-free survival was 80%. Prostate cancer-specific survival and overall survival at 10 years were 84% and 60%, respectively.

CONCLUSIONS

Although pCR was not met, the treatment demonstrated a modest toxicity profile and reasonable long-term outcomes, suggesting feasibility and safety. Further studies are needed to optimize endpoints and assess the efficacy of neoadjuvant treatments compared with standard approaches in high-risk prostate cancer patients.

Integrated analysis of single-cell and bulk transcriptomes uncovers clinically relevant molecular subtypes in human prostate cancer

Objective

Prostate cancer (PCa) is a complex disease characterized by diverse cellular ecosystems within the tumor microenvironment (TME) and high tumor heterogeneity, which challenges clinically stratified management and reinforces the need for novel strategies to fight against castration-resistant PCa (CRPC).

Methods

We performed single-cell RNA sequencing (scRNA-seq) on 10 untreated primary PCa tissues and integrated public scRNA-seq resources from three normal prostate tissues, two untreated primary PCa tissues, and six CRPC tumors to portray a comprehensive cellular and molecular interaction atlas of PCa. We further integrated the single-cell and bulk transcriptomes of PCa to establish a molecular classification system.

Results

scRNA-seq profiles revealed substantial inter- and intra-tumoral heterogeneity across different cell subpopulations in untreated PCa and CRPC tumors. In the malignant epithelial reservoir, cells evolved along decoupled paths in treatment-naive PCa and CRPC tumors, and distinct transcriptional reprogramming processes were activated, highlighting anti-androgen therapy-induced lineage plasticity. Based on the specifically expressed markers of the epithelial subpopulations, we conducted unsupervised clustering analysis in The Cancer Genome Atlas prostate adenocarcinoma (TCGA-PRAD) cohort and identified three molecularly and clinically distinct subtypes. The C1 subtype, characterized by high enrichment of CRPC-enriched epithelial cells, had a high risk of rapid development of anti-androgen resistance and might require active surveillance and additional promising intervention treatments, such as integrin A3 (ITGA3) + integrin B1 (ITGB1) inhibition. The C2 subtype resembled the immune-modulated subtype that was most likely to benefit from anti-LAG3 immunotherapy. The C3 subtype had a favorable prognosis.

Conclusions

Our study provides a comprehensive and high-resolution landscape of the intricate architecture of the PCa TME, and our trichotomic molecular taxonomy could help facilitate precision oncology.

Patient-Derived Organoid Models for NKT Cell-Based Cancer Immunotherapy

Invariant Natural Killer T (iNKT) cells are a unique subset of T cells that bridge innate and adaptive immunity, displaying potent anti-tumor properties through cytokine secretion, direct cytotoxicity, and recruitment of immune effector cells such as CD8+ T cells and NK cells. Despite their therapeutic potential, the immunosuppressive tumor microenvironment (TME), characterized by regulatory T cells, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs), limits iNKT cell efficacy. Patient-derived organoid (PDO) platforms provide an innovative model for dissecting these complex interactions and evaluating strategies to reinvigorate iNKT cell functionality within the TME. PDOs closely mimic the genetic, phenotypic, and structural characteristics of primary tumors, enabling the study of tumor-immune dynamics. Integrating iNKT cells into PDOs offers a robust platform for investigating CD1d-mediated interactions, Th1-biased immune responses driven by glycolipid analogs like α-GalCer, and combination therapies such as immune checkpoint inhibitors. Additionally, PDO systems can assess the effects of metabolic modulation, including reducing lactic acid accumulation or targeting glutamine pathways, on enhancing iNKT cell activity. Emerging innovations, such as organoid-on-a-chip systems, CRISPR-Cas9 gene editing, and multi-omics approaches, further expand the potential of PDO-iNKT platforms for personalized immunotherapy research. Although the application of iNKT cells in PDOs is still undeveloped, these systems hold immense promise for bridging preclinical studies and clinical translation. By addressing the challenges of the TME and optimizing therapeutic strategies, PDO-iNKT platforms offer a transformative avenue for advancing cancer immunotherapy and personalized medicine.

Prostate ductal adenocarcinoma with MLH1 copy number loss, microsatellite instability high and BRCA2 mutation

Mismatch repair deficiency (MMRd) or microsatellite instability high (MSI-H) is rare in prostate cancer and more frequently observed in cases with ductal histology. MLH1 copy number loss is extremely rare in MMRd tumors. Herein, we describe a case of prostate ductal adenocarcinoma with MLH1 copy number loss, microsatellite instability high and BRCA2 mutation could derive benefit from immunotherapy plus ADT. A 72-year-old Chinese patient was diagnosed with poorly differentiated prostate ductal adenocarcinoma mixed with acinar adenocarcinoma (Gleason 5 + 4). Next-generation sequencing (NGS) showed a hypermutated tumor with a mutational burden of 34.71 mutations per Mb and microsatellite instability high (MSI-H). Suspected biallelic MLH1 loss (copy number 0.16) and a pathogenic somatic BRCA2 variant (E2981Kfs*7) were detected. After surgery, the patient received androgen-deprivation therapy (ADT) with goserelin (10.8 mg every 3 months) and tislelizumab (200 mg every 3 weeks). At the 1-year follow-up, the PSA level was lower than 0.01 ng/ml and a pelvic MRI revealed no abnormalities. Our case highlights the intricate molecular mechanisms of MMRd prostate cancer.

Evolution of myeloid-mediated immunotherapy resistance in prostate cancer

Patients with advanced metastatic castration-resistant prostate cancer (mCRPC) are refractory to immune checkpoint inhibitors (ICIs)1,2, partly because there are immunosuppressive myeloid cells in tumours3,4. However, the heterogeneity of myeloid cells has made them difficult to target, making blockade of the colony stimulating factor-1 receptor (CSF1R) clinically ineffective. Here we use single-cell profiling on patient biopsies across the disease continuum and find that a distinct population of tumour-associated macrophages with elevated levels of SPP1 transcripts (SPP1hi-TAMs) becomes enriched with the progression of prostate cancer to mCRPC. In syngeneic mouse modelling, an analogous macrophage population suppresses CD8+ T cell activity in vitro and promotes ICI resistance in vivo. Furthermore, Spp1hi-TAMs are not responsive to anti-CSF1R antibody treatment. Pathway analysis identifies adenosine signalling as a potential mechanism for SPP1hi-TAM-mediated immunotherapeutic resistance. Indeed, pharmacological inhibition of adenosine A2A receptors (A2ARs) significantly reverses Spp1hi-TAM-mediated immunosuppression in CD8+ T cells in vitro and enhances CRPC responsiveness to programmed cell death protein 1 (PD-1) blockade in vivo. Consistent with preclinical results, inhibition of A2ARs using ciforadenant in combination with programmed death 1 ligand 1 (PD-L1) blockade using atezolizumab induces clinical responses in patients with mCRPC. Moreover, inhibiting A2ARs results in a significant decrease in SPP1hi-TAM abundance in CRPC, indicating that this pathway is involved in both induction and downstream immunosuppression. Collectively, these findings establish SPP1hi-TAMs as key mediators of ICI resistance in mCRPC through adenosine signalling, emphasizing their importance as both a therapeutic target and a potential biomarker for predicting treatment efficacy.

Implementing evidence-based strategies for men with biochemically recurrent and advanced prostate cancer: Consensus recommendations from the US Prostate Cancer Conference 2024

Current US clinical practice guidelines for advanced prostate cancer management contain recommendations based on high-level evidence from randomized controlled trials; however, these guidelines do not address the nuanced clinical questions that are unanswered by prospective trials but nonetheless encountered in day-to-day practice. To address these practical questions, the 2024 US Prostate Cancer Conference (USPCC 2024) was created to generate US-focused expert clinical decision-making guidance for circumstances in which level 1 evidence is lacking. At the second annual USPCC meeting (USPCC 2024), a multidisciplinary panel of experts convened to discuss ongoing clinical challenges related to 5 topic areas: biochemical recurrence; metastatic, castration-sensitive prostate cancer; poly [ADP-ribose] polymerase inhibitors; prostate-specific membrane antigen radioligand therapy; and metastatic, castration-resistant prostate cancer. Through a modified Delphi process, 34 consensus recommendations were developed and are intended to provide clinicians who manage prostate cancer with guidance related to the implementation of novel treatments and technologies. In this report, the authors review the areas of consensus identified by the USPCC 2024 experts and evaluate ongoing unmet needs regarding translational application of the current clinical evidence.

Intensification Approaches and Treatment Sequencing in Metastatic Castration-resistant Prostate Cancer: A Systematic Review

BACKGROUND AND OBJECTIVE

Recently, research on treatment intensification has gathered momentum, and three novel therapy combinations were approved for metastatic castration-resistant prostate cancer (mCRPC). This systematic review summarizes the current and emerging evidence around intensified strategies for mCRPC and provides guidance for an ideal therapeutic sequencing.

METHODS

Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines were followed to perform this review. PubMed, EMBASE, Web of Science, Cochrane Library, ClinicalTrials.gov, and major international societies' online proceedings were searched comprehensively until May 15, 2024, for terms related to treatment intensification and sequencing for mCRPC.

KEY FINDINGS AND LIMITATIONS

Overall, 28 clinical trials and 24 ongoing studies of intensification treatments were included in this review. Algorithms of optimal sequencing of approved treatments for mCRPC were outlined according to the use of androgen receptor pathway inhibitors (ARPIs) with or without docetaxel for earlier disease states. In first line, poly(ADP-ribose) polymerase inhibitor + ARPI combinations improve radiographical progression-free survival (rPFS), particularly for those with BRCA1/2 alterations. The AKT inhibitor combination of ipatasertib + abiraterone extends rPFS in those with PTEN loss or PIK3CA/AKT1/PTEN alterations. In those with two or more risk factors for early progression on enzalutamide, radionuclide 177-Lu-PSMA-617 + enzalutamide prolongs progression-free survival. Ongoing research of intensified approaches for mCRPC, and available and potential predictive and prognostic biomarkers are discussed.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Recent approvals and ongoing investigations of single agents and intensification approaches will keep transforming the mCRPC treatment landscape. Improvement of patient profiling applying recognized genomic, molecular, and clinical predictive and prognostic indicators is fundamental to optimize sequential use of available therapies.

Microsatellite instability and high tumor mutational burden detected by next generation sequencing are concordant with loss of mismatch repair proteins by immunohistochemistry

Impairment of DNA mismatch repair function in neoplasms can be assessed by DNA-based methods to assess for high microsatellite instability (MSI-High) or immunohistochemical (IHC) analysis to assess for deficiency of mismatch repair proteins (dMMR). Neoplasms with mismatch repair deficiency often have high tumor mutational burden (TMB-High). MSI-High, dMMR, and TMB-High are all histology agnostic biomarkers for potential therapy using immune checkpoint inhibitors (ICI). In this single center, retrospective study, our primary aim was to assess if NGS-based positive TMB/MSI findings are concordant with patient matched concurrent MMR IHC studies. In addition, we determined if positive TMB/MSI findings are attributable to genetic/epigenetic alterations of MMR genes. Finally, we explored potential associations between IHC, TMB and MSI findings and specific tumor types We screened 4,258 patients in our database who had tumor-normal-testing with our institutional high-throughput NGS-based CLIA assay between Apr 1, 2021-August 31, 2022 for TMB and MSI. We identified 65 patients who had neoplasms with documented TMB-High/MSI-High (n = 59) or TMB-High/MSI-Undetermined (n = 6) results as well as concurrent IHC results for MMR proteins [colorectal (n = 25), endometrial (n = 28), prostatic (n = 7), urothelial (n = 3), other (n = 5)]. The concordance between positive NGS TMB/MSI and MMR results was 98 %. Genetic/epigenetic alterations of MMR genes were documented in 78 % of the neoplasms. IHC studies for dMMR proteins revealed loss of MLH1/PMS2 (n = 33), MSH2/MSH6 (n = 14), MLH1/MSH2/PMS2 (n = 1), MLH1 (n = 1), MSH2 (n = 2), MSH6 (n = 6) and PMS2 (n = 6). All six prostatic neoplasms with dMMR had loss of MSH2/MSH6 (p < 0.0001). We conclude that neoplasms with positive results for TMB/MSI are highly concordant with positive dMMR results. Genetic/epigenetic alterations in the MMR genes are an underlying reason for most positive findings. The association of MSH2/MSH6 loss with prostatic neoplasms is of in-terest, but sample size is limited, and further studies are warranted to address this association.

Nivolumab in Patients with Metastatic Castration-Resistant Prostate Cancer with and without DNA Repair Defects

PURPOSE

Despite the success of immune checkpoint inhibitors (ICI) across various cancers, their efficacy in metastatic castration-resistant prostate cancer (mCRPC) is modest, except for a subset of patients who experience significant, yet unpredictable, benefits. DNA repair defects (DRD) are associated with higher neoantigen load, which may predict response. Our study explored the potential of DRD for enhanced responsiveness to the ICI nivolumab.

PATIENTS AND METHODS

We conducted a phase II, multicenter, single-arm trial evaluating nivolumab in patients with mCRPC with prior docetaxel therapy. The DRD were assessed using ctDNA. The primary endpoint was PSA50 response. Secondary endpoints included the objective response rate, radiographic progression-free survival (rPFS), and overall survival. Also, exploratory comprehensive genomic profiling was performed via whole-exome sequencing of tumor samples and matched normal tissues, alongside PD-L1 expression evaluation.

RESULTS

Among the 38 enrolled patients, DRD was identifiable in 30.5% (11/36) through ctDNA and/or whole-exome sequencing analyses. The overall PSA50 response rate was 10.5% (4/38). The PSA50 and objective response rates did not significantly differ between patients with and without DRD (18.2% vs. 8%; P = 0.57 and 50% vs. 17.6%; P = 0.27, respectively). The median PSA-PFS (1.9 vs. 2.8 months; P = 0.52) and rPFS (3.4 vs. 5.5 months; P = 0.7) were not statistically different between patients with and without DRD. Grade ≥ 3 adverse events were reported in 47.3% of participants.

CONCLUSIONS

Nivolumab has clinical activity in a subset of patients with mCRPC; however, DRD does not predict response. These results highlight the necessity of identifying new biomarkers to more accurately determine patients with mCRPC who might respond to ICIs.

Blood-based tumor mutational burden impacts clinical outcomes of immune checkpoint inhibitor treated breast and prostate cancers

BACKGROUND

Breast and prostate tumors are known to be less responsive to immune checkpoint inhibitors (ICIs). Tissue-based tumor mutation burden (tTMB) has emerged as a predictive biomarker of response to ICIs, including in these "cold tumors". In clinical practice, when tTMB is not available, blood-based TMB score (bTMB) can be used to consider treatment with ICIs.

METHODS

This retrospective, real-world study included a final cohort of metastatic breast and prostate cancer patients treated with an ICI following a liquid biopsy test. Multiple bTMB-High cut-offs were assessed. Clinical, genomic, and outcomes data were collected. We hypothesized that a cut-off of bTMB ≥10 mut/Mb is not a strong predictor of response to ICIs in this setting. The Guardant Health genomic database (GHGD) was then queried (N = 13,992) for associations of bTMB with genomic alterations.

RESULTS

In the clinical cohort (N = 48), ICI treatment is offered after a median of 3 (1-9) lines of treatment. The median bTMB is 16.4 (10-186) mut/Mb. The median time on ICI and PFS is 2.1 (0-1.7) and 3.1 months (95%CI, 1.6-4.6) respectively; no difference by MSI/MMR status (p = 0.152). Response rate among eligible patients (n = 36) is 16.7%; only N = 1/6 in bTMB <16 mut/Mb. High bMSI is associated with higher bTMB (correlation test, r = 0.66, p = 0.000). In the GHGD, patients with bTMB high have significantly more alterations than bTMB low and TP53, PIK3CA, ATM, ESR1, NF1, BRCA2, ARID1A, and APC were the most frequently altered genes.

CONCLUSIONS

In this study, the practice of offering an ICIs based on bTMB was uncommon and did not independently predict ICI benefits in patients with refractory, advanced breast and prostate cancers.

Comprehensive scRNA-seq analysis to identify new markers of M2 macrophages for predicting the prognosis of prostate cancer

BACKGROUND

Prostate cancer (PCa) has become the highest incidence of malignant tumor among men in the world. Tumor microenvironment (TME) is necessary for tumor growth. M2 macrophages play an important role in many solid tumors. This research aimed at the role of M2 macrophages' prognosis value in PCa.

METHODS

Single-cell RNA-seq (scRNA-seq) data and mRNA expression data were obtained from the Gene Expression Omnibus database (GEO) and The Cancer Genome Atlas (TCGA). Quality control, normalization, reduction, clustering, and cell annotation of scRNA-seq data were preformed using the Seruat package. The sub-populations of the tumor-associated macrophages (TAMs) were analysis and the marker genes of M2 macrophage were selected. Differentially expressed genes (DEGs) in PCa were identified using limma and the immune infiltration was detected using CIBERSORTx. Then, a weighted correlation network analysis (WGCNA) was constructed to identify the M2 macrophage-related modules and genes. Integration of the marker genes of M2 macrophage from scRNA-seq data analysis and hub genes from WGCNA to select the prognostic gene signature based on Univariate and LASSO regression analysis. The risk score was calculated, and the DEGs, biological function, immune characteristics related to risk score were explored. And a predictive nomogram was constructed. CCK8, Transwell, and wound healing were used to verify cell phenotype changes after co-cultured.

RESULTS

A total of 2431 marker genes of M2 macrophage and 650 hub M2 macrophage-related genes were selected based on scRNA-seq data and WGCNA. Then, 113 M2 macrophage-related genes were obtained by overlapping the scRNA-seq data and WGCNA results. Nine M2 macrophage-related genes (SMOC2, PLPP1, HES1, STMN1, GPR160, ABCG1, MAZ, MYC, and EPCAM) were screened as prognostic gene signatures. M2 risk score was calculated, the DEGs, Immune score, stromal score, ESTIMATE score, tumor purity, and immune cell infiltration, immune checkpoint expression, and responses of immunotherapy and chemotherapy were identified. And a predictive nomogram was constructed. CCK8, Transwell invasion, and wound healing further verified that M2 macrophages promoted the proliferation, invasion, and migration of PCa (p < 0.05).

CONCLUSIONS

We uncovered that M2 macrophages and relevant genes played key roles in promoting the occurrence, development, and metastases of PCa and played as convincing predictors in PCa.

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.

Ipilimumab with nivolumab in molecularly selected patients with castration-resistant prostate cancer: primary analysis of the phase II INSPIRE trial

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) typically exhibits resistance to immune checkpoint inhibitors (ICIs). However, a subset of mCRPC patients displays a more immunogenic profile. This study examines efficacy and safety of dual ICI therapy in molecularly selected mCRPC.

PATIENTS AND METHODS

This single-arm, phase II trial included 69 molecularly selected mCRPC patients with mismatch repair deficiency (dMMR), non-synonymous tumour mutational burden ≥7.1 muts/Mb (hTMB), a BRCA2 mutation (BRCAm), or biallelic CDK12 inactivation (CDK12i). Efficacy was assessed in ICI-naïve patients (cohort A) with RECIST 1.1 (A1) and Prostate Cancer Working Group 3 (A2) measurable disease. Safety was evaluated in cohorts A and B (prior ICI monotherapy). Treatment included nivolumab 3 mg/kg and ipilimumab 1 mg/kg every 3 weeks for four cycles, followed by nivolumab 480 mg every 4 weeks for up to 1 year. The primary endpoint was disease control rate beyond 6 months (DCR > 6), aiming to surpass a DCR > 6 of 22%.

RESULTS

Patients initiated treatment between January 2021 and February 2024. Cohort A included 65 patients. Of these, 21 had dMMR (32%), 8 had hTMB (12%), 20 had BRCAm (31%), and 16 had CDK12i (25%). DCR > 6 was achieved in 38% of patients [95% confidence interval (CI) 27% to 51%], and was highest in dMMR (81%), followed by hTMB (25%), CDK12i (19%), and BRCAm (15%). Objective response rate in cohort A was 38% (95% CI 22% to 55%) and 47% (95% CI 34% to 60%) exhibited a 50% decline in prostate-specific antigen levels. Median progression-free survival (PFS) was 4.0 months (95% CI 3.5-12.0 months) in cohort A, and 32.7 months (95% CI 21.8 months-not reached) in dMMR patients. Treatment-related adverse events (TRAEs) led to permanent discontinuation in 14 of 69 patients (20%). Grade ≥3 TRAEs occurred in 48% of patients, with diarrhoea and elevated transaminases each in 10%. There was one treatment-related death due to a bowel perforation and a second following euthanasia after grade 4 toxicity.

CONCLUSIONS

This trial of dual ICIs in molecularly selected mCRPC met its primary endpoint, showing DCR > 6 in 38% of patients. Dual ICIs exhibited modest responses in the hTMB, BRCAm, and CDK12i subgroups, but demonstrated exceptional efficacy in dMMR.

Immunome profiling in prostate cancer: a guide for clinicians

Tumor immune microenvironment (TIME) plays a key role to understand how tumors respond to prostate cancer (PC) therapies and potential mechanisms of resistance. Previous research has suggested that specific genomic aberrations, such as microsatellite instability (MSI) or CDK12 bi-allelic loss can allow PC patients more likely to respond to immune checkpoint inhibitors (ICI) or other immune therapies. However, responses to these treatments remain highly variable even in selected patients. Thus, it is essential to obtain more information about tumor immune cells that infiltrate these tumors, and on their plasticity and interactions, in order to better understand the underlying biology to allow development of new therapeutic strategies. This review analyzes: 1) How interactions among immune cell populations and other cells infiltrating the tumor stroma can modulate the progression of PC, 2) How the standard therapies to treat PC (such as androgen deprivation therapy, new androgen-directed hormone therapy or chemotherapy) may influence the dynamic changes of the immunome and 3) What are the limitations in characterizing the immune landscape of the host´s response to tumors.

AI-Powered cellular morphometric biomarkers discovered in needle biopsy of prostatic cancer predict neoadjuvant androgen deprivation therapy response and prognosis: an international multicenter retrospective study

It is imperative to identify patients with prostate cancer (PCa) who will benefit from androgen receptor signaling inhibitors that can impact quality of life upon prolonged use. Using our extensively-validated artificial-intelligence technique: cellular morphometric biomarker via machine learning (CMB-ML), we identified 13 CMBs from whole slide images of needle biopsies from the trial specimens ( NCT02430480 , n=37) that accurately predicted response to neoadjuvant androgen deprivation therapy (NADT) (AUC: 0.980). Notably, 13-CMB model stratified PCa patients into responder and non-responder groups after NADT treatment in an independent hospital cohort (n=122) that significantly associated with pathologic complete response (p=0.0005), biochemical-recurrence-free survival (p=0.024) and mTOR signaling pathway (p=0.03), suggesting potentially more clinical benefit from mTOR inhibitors in non-responder group. Additionally, genetic and genomic analysis revealed interplay between genetic variants and CMBs on NADT resistance, and provided molecular annotations for CMBs. Overall, prospective clinical implementation of 13-CMB model could assist precision care of PCa patients.

Significance

We describe a highly accurate CMB model to predict the therapeutic benefit in prostate cancer patients and uncover the complex interplay between genetic variants and CMBs on NADT resistance. Our model relies only on widely available needle biopsy specimens and provides a robust and cost-effective solution for clinical implementation.

YAP1 Inhibition Induces Phenotype Switching of Cancer-Associated Fibroblasts to Tumor Suppressive in Prostate Cancer

Prostate cancer rarely responds to immune-checkpoint blockade (ICB) therapies. Cancer-associated fibroblasts (CAF) are critical components of the immunologically "cold" tumor microenvironment and are considered a promising target to enhance the immunotherapy response. In this study, we aimed to reveal the mechanisms regulating CAF plasticity to identify potential strategies to switch CAFs from protumorigenic to antitumor phenotypes and to enhance ICB efficacy in prostate cancer. Integration of four prostate cancer single-cell RNA sequencing datasets defined protumorigenic and antitumor CAFs, and RNA-seq, flow cytometry, and a prostate cancer organoid model demonstrated the functions of two CAF subtypes. Extracellular matrix-associated CAFs (ECM-CAF) promoted collagen deposition and cancer cell progression, and lymphocyte-associated CAFs (Lym-CAF) exhibited an antitumor phenotype and induced the infiltration and activation of CD8+ T cells. YAP1 activity regulated the ECM-CAF phenotype, and YAP1 silencing promoted switching to Lym-CAFs. NF-κB p65 was the core transcription factor in the Lym-CAF subset, and YAP1 inhibited nuclear translocation of p65. Selective depletion of YAP1 in ECM-CAFs in vivo promoted CD8+ T-cell infiltration and activation and enhanced the therapeutic effects of anti-PD-1 treatment on prostate cancer. Overall, this study revealed a mechanism regulating CAF identity in prostate cancer and highlighted a therapeutic strategy for altering the CAF subtype to suppress tumor growth and increase sensitivity to ICB. Significance: YAP1 regulates cancer-associated fibroblast phenotypes and can be targeted to switch cancer-associated fibroblasts from a protumorigenic subtype that promotes extracellular matrix deposition to a tumor-suppressive subtype that stimulates antitumor immunity and immunotherapy efficacy.

The evaluation of cyclin D1 expression in prostate carcinoma cases

OBJECTIVE

Cyclin D1 (CDDN1) is an important protein for mitotic cell cycle advancement through the G1 phase and contributes to the control of the cyclin-dependent kinases CDK4 and CDK6. We evaluated the relationship between CDDN1 expression and clinicopathological features in prostate cancer (PCa) cases and whether CDDN1 could be used as a prognostic biomarker for PCa cases in this study.

METHODS

This study comprised ninety cases; seventy-five had PCa and fifteen had benign prostatic hypertrophy (BPH) diagnoses (as the control group). The pathological specimens were stained immunohistochemically and categorized as a 'low' (L) or a 'high' (H) group for CDDN1 expression. The cases' clinicopathological features and survival rates were evaluated statistically, within a 95% confidence interval, p<0.05, retrospectively.

RESULTS

The median follow-up time was 75 (17-96) months, and the median overall survival (OS) was 87 months (CI 95%: 74.74-99.25). While the OS was 66 months (CI 95%: 49.61-82.38) in the H-CDDN1 group, the OS of the L-CDDN1 group was not yet reached. The OS of the L-CDDN1 group was longer in statistical significance (p=0.011). A Cox regression analysis revealed that the levels of CDDN1 expression, the values of lactate dehydrogenase, and post-treatment prostate specific antigen were found to be prognostic factors for OS in PCa cases (p<0.05).

CONCLUSION

Our results suggest the overexpression of CDDN1 is a potentially useful but poor prognostic biomarker for PCa cases.

The Role of Microsatellite Instability/DNA Mismatch Repair Deficiency and Tumor Mutational Burden as Biomarkers in Predicting Response to Immunotherapy in Castration-resistant Prostate Cancer

Large trials of immune checkpoint inhibitors (ICIs) in castration-resistant prostate cancer (CRPC) have mostly failed. Biomarker-selected CRPC patients, especially those with high microsatellite instability (MSI-H), mismatch repair deficiency (dMMR), or elevated tumor mutational burden (TMB), may benefit from single-agent ICIs. Despite their rarity in CRPC (∼2-5%), identification of MSI-H, dMMR, or TMB-H could improve patient selection for immunotherapy.

French AFU Cancer Committee Guidelines - Update 2024-2026: Prostate cancer - Diagnosis and management of localised disease

OBJECTIVE

The aim of the Oncology Committee of the French Urology Association is to propose updated recommendations for the diagnosis and management of localized prostate cancer (PCa).

METHODS

A systematic review of the literature from 2022 to 2024 was conducted by the CCAFU on the elements of diagnosis and therapeutic management of localized PCa, evaluating references with their level of evidence.

RESULTS

The recommendations set out the genetics, epidemiology and diagnostic methods of PCa, as well as the concepts of screening and early detection. MRI, the reference imaging test for localized cancer, is recommended before prostate biopsies are performed. Molecular imaging is an option for disease staging. Performing biopsies via the transperineal route reduces the risk of infection. Active surveillance is the standard treatment for tumours with a low risk of progression. Therapeutic methods are described in detail, and recommended according to the clinical situation.

CONCLUSION

This update of French recommendations should help to improve the management of localized PCa.

Inhibition of PIM kinase in tumor associated macrophages suppresses inflammasome activation and sensitizes prostate cancer to immunotherapy

Immunotherapy has changed the treatment paradigm for many types of cancer, but immune checkpoint inhibitors (ICIs) have not shown benefit in prostate cancer (PCa). Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment (TME) and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. Here, we identify PIM kinases as important regulators of inflammasome activation in tumor associated macrophages (TAMs). Analysis of clinical data from a cohort of treatment naïve, hormone responsive PCa patients revealed that tumors from patients with high PIM1/2/3 display an immunosuppressive TME characterized by high inflammation (IL-1β and TNFα) and a high density of repressive immune cells, most notably TAMs. Strikingly, macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of prostate cancer. Transcriptional analyses indicate that eliminating PIM from macrophages enhanced the adaptive immune response and increased cytotoxic immune cells. Combined treatment with PIM inhibitors and ICIs synergistically reduced tumor growth. Immune profiling revealed that PIM inhibitors sensitized PCa tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Collectively, our data implicate macrophage PIM as a driver of inflammation that limits the potency of ICIs and provides preclinical evidence that PIM inhibitors are an effective strategy to improve the efficacy of immunotherapy in prostate cancer.

Immunological facets of prostate cancer and the potential of immune checkpoint inhibition in disease management

Prostate cancer (PCa) is the most common non-cutaneous cancer in men and a major cause of cancer-related deaths. Whereas localized PCa can be cured by surgery and radiotherapy, metastatic disease can be treated, but is not curable. Inhibition of androgen signaling remains the main therapeutic intervention for treatment of metastatic PCa, in addition to chemotherapy, radionuclide therapy and emerging targeted therapies. Although initial responses are favorable, resistance to these therapies invariably arise with development of castration resistant PCa (CRPC) and lethal phenotypes. Recent findings have implicated the crosstalk between PCa cells and the tumor microenvironment (TME) as a key factor for disease progression and metastasis, and the immune system is becoming an increasingly attractive target for therapy. Given the striking success of immune checkpoint inhibitors (ICIs) in various cancer types, preclinical and clinical studies have begun to explore their potential in PCa. It has become clear that the PCa TME is largely immunosuppressive, and ICI therapy does not have efficacy for PCa. Intense effort is therefore being made in the field to understand the mechanisms of suppression and to turn the immunosuppressive TME into an immune active one that would enable ICI efficacy. Herein we examine this recent body of knowledge and how the mutational landscape of PCa integrates with an immunosuppressive TME to circumvent ICI-mediated T-cell activity and tumor killing. We then review the emerging potential success of combinatorial ICI approaches, utility of careful patient selection, and potential novel strategies to improve the efficacy of ICI for PCa therapy.

Navigating therapeutic sequencing in the metastatic castration-resistant prostate cancer patient journey

BACKGROUND

Novel therapies for metastatic castration-resistant prostate cancer (mCRPC) have improved patient outcomes. However, there is uncertainty on the optimal selection of therapeutic agents for subsequent lines of therapy.

METHODS

We conducted a comprehensive review of published evidence from pivotal clinical trials and recent guidelines for the treatment of mCRPC. We further identify gaps in knowledge and areas for future research.

RESULTS

Key considerations to help guide treatment selection for patients with mCRPC include personal treatment history, individual clinical characteristics, symptoms, prognosis, availability of clinical trials, and other patient-specific factors. Genetic testing and prostate-specific membrane antigen-targeted imaging are important tools to evaluate candidacy for newer therapeutic options such as poly (ADP-ribose) polymerase inhibitors, alone or in combination with androgen receptor pathway inhibitors, and [177Lu]Lu-PSMA-617.

CONCLUSION

This article provides an overview of the evolving treatment landscape of mCRPC, discussing guideline-recommended treatment options and data from key clinical trials, while highlighting ongoing trials that may impact the future treatment landscape. Recommendations for optimal treatment sequencing based on individual patient factors are provided.

Preliminary Efficacy, Tolerability, and Safety Analysis of Darolutamide for Metastatic Castration-Resistant Prostate Cancer: A Single-Center, Open-Label Study

INTRODUCTION

Darolutamide is a structurally unique second-generation androgen receptor antagonist that has been approved for indications in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) and metastatic hormone-sensitive prostate cancer (mHSPC). The aim was to assess the efficacy and safety of Darolutamide for mCRPC.

METHODS

In this single-center, open-label study, patients with previously untreated mCRPC were enrolled and received androgen deprivation therapy (goserelin acetate 3.6 mg every 28 days) and docetaxel (75 mg per square meter of body surface area every 21 days) with Denosumab (120 mg every 28 days) for bone metastases, Darolutamide (300 mg orally twice daily) in the experimental group, and the control group received the corresponding of placebo. Serum PSA changes were detected and recorded, and imaging changes and adverse events (AEs) were evaluated. The primary endpoints were safety, tolerability, and antitumor efficacy, and the second endpoint was radiographic progression-free survival (rPFS).

RESULTS

Thirty-seven patients with mCRPC were enrolled. The median time to PSA50 in the Darolutamide group was 1.5 months (95% CI: 0.2619-0.9545), significantly lower than that in the placebo group (3.0 months [95% CI: 1.048-3.818], p = 0.0259). The median time to PSA90 in the experimental group was 4 months (95% CI: 0.3094-1.437), 2 months shorter than that in the placebo group (6.0 months [95% CI: 0.6961-3.232]). With the median follow-up of 6 months, the median decrease in serum PSA was -81.8% (range -60.4 to -99.9%) in the Darolutamide group and -69.4% (range -50.3 to -89.6%) in the placebo group. Tumor-related pain and AEs were not increased, and the median rPFS was not reached.

CONCLUSIONS

The combination of Darolutamide and docetaxel was well tolerated with more clinically beneficial than docetaxel alone in previously untreated mCRPC. Darolutamide rapidly reduced PSA levels and prolonged rPFS and did not increase the incidence of AEs.

Prostate cancer microenvironment: multidimensional regulation of immune cells, vascular system, stromal cells, and microbiota

BACKGROUND

Prostate cancer (PCa) is one of the most prevalent malignancies in males worldwide. Increasing research attention has focused on the PCa microenvironment, which plays a crucial role in tumor progression and therapy resistance. This review aims to provide a comprehensive overview of the key components of the PCa microenvironment, including immune cells, vascular systems, stromal cells, and microbiota, and explore their implications for diagnosis and treatment.

METHODS

Keywords such as "prostate cancer", "tumor microenvironment", "immune cells", "vascular system", "stromal cells", and "microbiota" were used for literature retrieval through online databases including PubMed and Web of Science. Studies related to the PCa microenvironment were selected, with a particular focus on those discussing the roles of immune cells, vascular systems, stromal cells, and microbiota in the development, progression, and treatment of PCa. The selection criteria prioritized peer-reviewed articles published in the last five years, aiming to summarize and analyze the latest research advancements and clinical relevance regarding the PCa microenvironment.

RESULTS

The PCa microenvironment is highly complex and dynamic, with immune cells contributing to immunosuppressive conditions, stromal cells promoting tumor growth, and microbiota potentially affecting androgen metabolism. Vascular systems support angiogenesis, which fosters tumor expansion. Understanding these components offers insight into the mechanisms driving PCa progression and opens avenues for novel therapeutic strategies targeting the tumor microenvironment.

CONCLUSIONS

A deeper understanding of the PCa microenvironment is crucial for advancing diagnostic techniques and developing precision therapies. This review highlights the potential of targeting the microenvironment to improve patient outcomes, emphasizing its significance in the broader context of PCa research and treatment innovation.

Biomarkers in head and neck squamous cell carcinoma: unraveling the path to precision immunotherapy

Recent strides in understanding the molecular underpinnings of head and neck cancers have sparked considerable interest in identifying precise biomarkers that can enhance prognostication and enable personalized treatment strategies. Immunotherapy has particularly revolutionized the therapeutic landscape for head and neck squamous cell carcinoma, offering new avenues for treatment. This review comprehensively examines the application and limitations of the established and emerging/novel biomarkers for head and neck squamous cell carcinoma. Established biomarkers, including well-characterized genetic mutations, protein expressions, and clinical factors, have been extensively studied and validated in clinical practice. Novel biomarkers identified through molecular analyses, including novel genetic alterations, immune-related markers, and molecular signatures, are currently being investigated and validated in preclinical and clinical settings. Biomarkers hold the potential to deepen our understanding of head and neck squamous cell carcinoma biology and guide therapeutic strategies. The evolving paradigm of predictive biomarkers facilitates the study of individual responses to specific treatments, including targeted therapy and immunotherapy.

Personalized treatment using predictive biomarkers in solid organ malignancies: A review

In recent years, the influence of specific biomarkers in the diagnosis and prognosis of solid organ malignancies has been increasingly prominent. The relevance of the use of predictive biomarkers, which predict cancer response to specific forms of treatment provided, is playing a more significant role than ever before, as it affects diagnosis and initiation of treatment, monitoring for efficacy and side effects of treatment, and adjustment in treatment regimen in the long term. In the current review, we explored the use of predictive biomarkers in the treatment of solid organ malignancies, including common cancers such as colorectal cancer, breast cancer, lung cancer, prostate cancer, and cancers associated with high mortalities, such as pancreatic cancer, liver cancer, kidney cancer and cancers of the central nervous system. We additionally analyzed the goals and types of personalized treatment using predictive biomarkers, and the management of various types of solid organ malignancies using predictive biomarkers and their relative efficacies so far in the clinical settings.

Patterns and Frequency of Pathogenic Germline Variants Among Prostate Cancer Patients Utilizing Multi-Gene Panel Genetic Testing

Background

Germline genetic testing (GGT) has significant implications in the management of patients with prostate cancer (PCa). Herein, we report on patterns and frequency of pathogenic/likely pathogenic germline variants (P/LPGVs) among newly diagnosed Arab patients with PCa.

Methods

Patients meeting the National Comprehensive Cancer Network (NCCN) eligibility criteria for GGT were offered a 19-gene PCa panel or an expanded 84-gene multi-cancer panel.

Results

During the study period, 231 patients were enrolled; 107 (46.3%) had metastatic disease at diagnosis. In total, 17 P/LPGVs were detected in 17 patients (7.4%). Among the 113 (48.9%) patients who underwent GGT with the 19-gene panel, eight (7.1%) had P/LPGVs, compared to nine (7.6%) of the 118 (51.1%) who did GGT through the expanded 84-gene panel (P = 0.88). Variant of uncertain significance (VUS) rate was higher (n = 73, 61.9%) among the group who underwent expanded 84-gene panel testing compared to those who underwent the 19-gene PCa panel (n = 35, 30.9%) (P = 0.001). P/LPGVs in DNA damage repair (DDR) genes, most frequently BRCA2, CHEK2 and TP53, were the most common P/LPGVs findings.

Conclusion

This study is the first to characterize the germline genetic profile of an Arab population with PCa. All detected P/LPGVs were potentially actionable, with most variants able to be detected with a PCa-specific panel.

Advances in and prospects of immunotherapy for prostate cancer

Immunotherapy has shown promising therapeutic effects in hematological malignancies and certain solid tumors and has emerged as a critical and highly potential treatment modality for cancer. However, prostate cancer falls under the category of immune-resistant cold tumors, for which immunotherapy exhibits limited efficacy in patients with solid tumors. Thus, it is important to gain a deeper understanding of the tumor microenvironment in prostate cancer to facilitate immune system activation and overcome immune suppression to advance immunotherapy for prostate cancer. In this review, we discuss the immunosuppressive microenvironment of prostate cancer, which is characterized by the presence of few tumor-infiltrating lymphocytes, abundant immunosuppressive cells, low immunogenicity, and a noninflammatory phenotype, which significantly influences the efficacy of immunotherapy for prostate cancer. Immunotherapy is mainly achieved by activating the host immune system and overcoming immunosuppression. In this regard, we summarize the therapeutic advances in immune checkpoint blockade, immunogenic cell death, reversal of the immunosuppressive tumor microenvironment, tumor vaccines, immune adjuvants, chimeric antigen receptor T-cell therapy, and overcoming penetration barriers in prostate cancer, with the aim of providing novel research insights and approaches to enhance the effectiveness of immunotherapy for prostate cancer.

Left out in the cold: Moving beyond hormonal therapy for the treatment of immunologically cold prostate cancer with CAR T cell immunotherapies

Prostate cancer is primarily hormone-dependent, and medical treatments have focused on inhibiting androgen biosynthesis or signaling through various approaches. Despite significant advances with the introduction of androgen receptor signalling inhibitors (ARSIs), patients continue to progress to castration-resistant prostate cancer (CRPC), highlighting the need for targeted therapies that extend beyond hormonal blockade. Chimeric Antigen Receptor (CAR) T cells and other engineered immune cells represent a new generation of adoptive cellular therapies. While these therapies have significantly enhanced outcomes for patients with hematological malignancies, ongoing research is exploring the broader use of CAR T therapy in solid tumors, including advanced prostate cancer. In general, CAR T cell therapies are less effective against solid cancers with the immunosuppressive tumor microenvironment hindering T cell infiltration, activation and cytotoxicity following antigen recognition. In addition, inherent tumor heterogeneity exists in patients with advanced prostate cancer that may prevent durable therapeutic responses using single-target agents. These barriers must be overcome to inform clinical trial design and improve treatment efficacy. In this review, we discuss the innovative and rationally designed strategies under investigation to improve the clinical translation of cellular immunotherapy in prostate cancer and maximise therapeutic outcomes for these patients.