Update on Systemic Prostate Cancer Therapies: Management of Metastatic Castration-resistant Prostate Cancer in the Era of Precision Oncology

Contemporary Treatment Patterns and Oncological Outcomes of Metastatic Hormone-sensitive Prostate Cancer and First- to Sixth- line Metastatic Castration-resistant Prostate Cancer Patients

Background and objective

With approval of novel systemic therapies within the past decade for metastatic hormone-sensitive (mHSPC) and castration-resistant (mCRPC) prostate cancer, patients may receive several therapy lines. However, the use of these treatments is under an ongoing change. We investigated contemporary treatment trends and progression-free (PFS) and overall (OS) survival of different therapy lines.

Methods

Relying on our institutional tertiary-care database, we identified mHSPC and mCRPC patients. The main outcome consisted of treatment changes (estimated annual percentage change [EAPC]) within the past decade, as well as PFS and OS for different mHSPC and mCRPC treatment lines.

Key findings and limitations

In 1098 metastatic patients, the median age was 70 yr with a median of two systemic therapy lines. For first-line mCRPC between 2013 and 2023, androgen deprivation monotherapy (ADT) monotherapy usage decreased significantly from 31% to 0% (EAPC -38.3%, p < 0.001), while the administration of chemotherapy increased from 16.7% to 33.3% (EAPC: +10.1%, p < 0.001). The PFS/OS rates of mHSPC patients was 21/67 mo, and those for first-, second-, third-, fourth-, fifth-, and sixth-line mCRPC patients were 11/47, eight of 30, seven of 24, six of 19, seven of 17, and seven of 13 mo, respectively. With an increased number of new combination therapy lines received, the median OS in mCRPC improved from 26 mo (one systemic treatment) to 52 mo (two or more lines of systemic treatment).

Conclusions and clinical implications

Significant changes in treatment patterns could be observed for mHSPC and mCRPC patients within the past decade, and usage of ADT monotherapy has decreased rapidly in real-world practice. Moreover, PFS decreases significantly with every therapy line, and OS increases with the implementation of new therapies.

Patient summary

Improvements in the real-world setting regarding the usage of combination therapies for metastatic hormone-sensitive and castration-resistant prostate cancer were made, which is reflected in contemporary survival outcomes.

Investigating miR-6880-5p in extracellular vesicle from plasma as a prognostic biomarker in endocrine therapy-treated castration-resistant prostate cancer

BACKGROUND

Advancements in the diagnosis, treatment, and surveillance of castration-resistant prostate cancer (CRPC) have progressed considerably, but a new biomarker that combines existing clinical and pathological data could be useful for a more precise diagnosis and prognosis. Some investigations have found that extracellular vesicle (EV)-derived miRNAs play crucial roles in various types of malignant tumors. The objective of this study was to explore EV miRNA and identify its biologic function as a biomarker for the diagnosis and prognosis of CRPC.

METHODS

Plasma samples were collected from five healthy donors (Control, CT) and 17 CRPC patients, categorizing into two groups based on their endocrine treatment response: partial response (PR; n = 10) and progressive disease (PD; n = 7). Candidate extracellular vesicle (EV) miRNAs were identified using miRNA microarray and RT-qPCR. The biological functions of the selected miRNAs were evaluated using the MTT assay, wound healing assay, trans-well assay, and RNA sequencing in CRPC cells after transient miRNA expression.

RESULTS

Microarray analysis revealed a significant downregulation of EV-miR-6880-5p in the PD samples compared to both CT and PR samples (p < 0.01). The expression of EV-miR-6880-5p in CRPC patients was decreased compared with that CT group (p = 0.0336) using RT-qPCR. In the PR group, EV-miR-6880-5p was increased at follow-up compared with the baseline (p = 0.2803), while in the PD group, it decreased at follow-up compared with the baseline samples (p = 0.4356). Furthermore, overexpression of miR-6880-5p hampered cell proliferation, migration, and invasion, downregulated pathways associated with tumor progression, and simultaneously upregulated pathways associated with cell growth and apoptosis in CRPC cells.

CONCLUSIONS

EV-miR-6880-5p shows promise as a prognostic biomarker in patients with CRPC. Further, prospective validations are necessary to evaluate the potential of these candidate miRNAs.

Sedation-free pediatric [18F]FDG imaging on totalbody PET/CT with the assistance of artificial intelligence

PURPOSE

While sedation is routinely used in pediatric PET examinations to preserve diagnostic quality, it may result in side effects and may affect the radiotracer's biodistribution. This study aims to investigate the feasibility of sedation-free pediatric PET imaging using ultra-fast total-body (TB) PET scanners and deep learning (DL)-based attenuation and scatter correction (ASC).

METHODS

This retrospective study included TB PET (uExplorer) imaging of 35 sedated pediatric patients under four years old to determine the minimum effective scanning time. A DL-based ASC method was applied to enhance PET quantification. Both quantitative and qualitative assessments were conducted to evaluate the image quality of ultra-fast DL-ASC PET. Five non-sedated pediatric patients were subsequently used to validate the proposed approach.

RESULTS

Comparisons between standard 300-second and ultra-fast 15-second imaging, CT-ASC and DL-ASC ultra-fast 15-second images, as well as DL-ASC ultra-fast 15-second images in non-sedated and sedated patients, showed no significant differences in qualitative scoring, lesion detectability, and quantitative Standard Uptake Value (SUV) (P = ns).

CONCLUSIONS

This study demonstrates that pediatric PET imaging can be effectively performed without sedation by combining ultra-fast imaging techniques with a DL-based ASC. This advancement in sedation-free ultra-fast PET imaging holds potential for broader clinical adoption.

Correlation analyses of radiographic progression-free survival with clinical and health-related quality of life outcomes in metastatic castration-resistant prostate cancer: Analysis of the phase 3 VISION trial

BACKGROUND

[177Lu]Lu-PSMA-617 (177Lu-PSMA-617) plus protocol-permitted standard of care (SOC) prolonged overall survival (OS) and radiographic progression-free survival (rPFS) versus SOC in patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) in the phase 3 VISION study, in addition to beneficial effects on symptomatic skeletal events (SSEs) and health-related quality of life (HRQOL).

METHODS

Post hoc analyses used the full analysis set from the VISION study (N = 831) overall and by randomized treatment arm (177Lu-PSMA-617 plus SOC, n = 551; SOC, n = 280). Correlations were determined between OS and rPFS and between rPFS or OS and time to SSE or to worsening HRQOL (Functional Assessment of Cancer Therapy-Prostate [FACT-P] and 5-level EQ-5D [EQ-5D-5L]). Correlation analyses used an iterative multiple imputation copula-based approach (correlation coefficients [rho] of <0.3 were defined as weak, ≥0.3 and <0.5 as mild, ≥0.5 and <0.7 as moderate, and ≥0.7 as strong).

RESULTS

In the overall population, rPFS correlated strongly with OS (rho, ≥0.7). Correlations between rPFS or OS and time to SSE without death were weak or mild. Time to worsening in the FACT-P total score and emotional and physical well-being domains correlated mildly or moderately with rPFS and moderately with OS. Correlation coefficients for time-to-worsening EQ-5D-5L scores were mild to moderate for both rPFS and OS. Correlation coefficients were similar between treatment arms.

CONCLUSIONS

In this analysis of the VISION study, rPFS correlated strongly with OS but not with time to SSE or worsening HRQOL. These findings require further investigation.

The current landscape of stereotactic body radiation therapy for metastatic castration-resistant prostate cancer

BACKGROUND

The onset of castration-resistance is associated with dismal outcomes in patients with prostate cancer (PCa). Metastasis directed therapy has been investigated in multiple disease settings and may improve outcomes in selected patients. Our systematic review aims to summarize evidence with stereotactic body radiotherapy (SBRT) in castration-resistant prostate cancer (CRPC).

METHODS

The literature search was performed on March 2024, on Pubmed, using the keywords "SBRT" AND "CRPC", and "stereotactic ablative radiotherapy (SABR)" AND "CRPC". This search retrieved a total of 108 articles, 19 were included.

RESULTS

The literature is largely dominated by retrospective series. In men with metachronous oligoprogression, SBRT with androgen receptor pathway inhibitor significantly increased progression-free survival (PFS) including biochemical progression-free survival in a randomized phase II trial (hazard ratio of 0.35, p < 0.001). In patients continuing ADT, the bPFS ranged between 9.5 months to 17.9 months, and next systemic treatment-free survival (NEST-FS) reached up to 2 years. In men with induced oligoprogression, SBRT enabled NEST-FS up to 3 years. SBRT was well tolerated, with less than 5% grade 3 toxicity reported across studies.

CONCLUSION

In the population of patients with oligometastatic CRPC, SBRT enables long-term biochemical response and PFS. In the oligoprogressive setting, SBRT could be integrated to prolong the duration and efficacy of systemic therapies. Nevertheless, the level of evidence remains very low and inclusion within prospective trials remain the preferred option for this population of patients.

Mesenchymal stem cell-derived exosomes for management of prostate cancer: An updated view

Prostate cancer represents the second most prevalent form of cancer found in males, and stands as the fifth primary contributor to cancer-induced mortality on a global scale. Research has shown that transplanted mesenchymal stem cells (MSCs) can migrate by homing to tumor sites in the body. In prostate cancer, researchers have explored the fact that MSC-based therapies (including genetically modified delivery vehicles or vectors) and MSC-derived exosomes are emerging as attractive options to improve the efficacy and safety of traditional cancer therapies. In addition, researchers have reported new insights into the application of extracellular vesicle (EV)-MSC therapy as a novel treatment option that could provide a more effective and targeted approach to prostate cancer treatment. Moreover, the new generation of exosomes, which contain biologically functional molecules as signal transducers between cells, can simultaneously deliver different therapeutic agents and induce an anti-tumor phenotype in immune cells and their recruitment to the tumor site. The results of the current research on the use of MSCs in the treatment of prostate cancer may be helpful to researchers and clinicians working in this field. Nevertheless, it is crucial to emphasize that although dual-role MSCs show promise as a therapeutic modality for managing prostate cancer, further investigation is imperative to comprehensively grasp their safety and effectiveness. Ongoing clinical trials are being conducted to assess the viability of MSCs in the management of prostate cancer. The results of these trials will help determine the viability of this approach. Based on the current literature, engineered MSCs-EV offer great potential for application in targeted tumor therapy.

Prostein expression on circulating tumor cells as a prognostic marker in metastatic castration-resistant prostate cancer

BACKGROUND

Identification of emerging molecular biomarkers on circulating tumor cells (CTCs) represents an attractive feature of liquid biopsy that facilitates precision and tailored medicine in the management of metastatic castration-resistant prostate cancer (mCRPC). Prostein is an androgen-regulated transmembrane protein with high prostate specificity. Prostein-positive circulating tumor cell (CTC) was recently suggested to have diagnostic potential; however, no study has been conducted to evaluate its prognostic value in mCRPC.

METHODS

CTCs from mCRPC patients were enumerated using the CellSearch System. Prostein-positive CTCs were identified by immunostaining results. The relationships between prostein expression on CTCs and PSA response rate, PSA progression-free survival (PSA-PFS), radiographic progression-free survival (PFS), and overall survival (OS) were tested by Fisher's exact test or evaluated using Kaplan-Meier and multivariate Cox analyses.

RESULTS

Prostein-positive CTCs were identified in 31 of 87 baseline samples from mCRPC patients and 16 of 51 samples collected at the first follow-up visit. PSA response rates were significantly lower in baseline prostein-positive patients (0%, 0/31) than in prostein-negative patients (19.6%, 11/56) (p = 0.007). The 31 prostein-positive patients had significantly shorter PSA-PFS (p < 0.001), radiographic PFS (p < 0.001), and OS (p = 0.018), compared to the 56 prostein-negative patients at baseline. The association with PSA-PFS maintained its significance (p = 0.028) in multivariate analyses. Analyzing prostein expression at the first follow-up as well as the conversion of prostein expression from baseline to follow-up samples not only confirmed the association with PSA-PFS, but also demonstrated prognostic significance with OS.

CONCLUSION

Our study provides the first evidence to support the potential of prostein expression on CTCs to serve as a novel prognostic marker in mCRPC patients. Future large-scale prospective studies are needed to validate our findings.

Mining bone metastasis related key genes of prostate cancer from the STING pathway based on machine learning

Background

Prostate cancer (PCa) is the second most prevalent malignant tumor in male, and bone metastasis occurs in about 70% of patients with advanced disease. The STING pathway, an innate immune signaling mechanism, has been shown to play a key role in tumorigenesis, metastasis, and cancerous bone pain. Hence, exploring regulatory mechanism of STING in PCa bone metastasis will bring novel opportunities for treating PCa bone metastasis.

Methods

First, key genes were screened from STING-related genes (SRGs) based on random forest algorithm and their predictive performance was evaluated. Subsequently, a comprehensive analysis of key genes was performed to explore their roles in prostate carcinogenesis, metastasis and tumor immunity. Next, cellular experiments were performed to verify the role of RELA in proliferation and migration in PCa cells, meanwhile, based on immunohistochemistry, we verified the difference of RELA expression between PCa primary foci and bone metastasis. Finally, based on the key genes to construct an accurate and reliable nomogram, and mined targeting drugs of key genes.

Results

In this study, three key genes for bone metastasis were mined from SRGs based on the random forest algorithm. Evaluation analysis showed that the key genes had excellent prediction performance, and it also showed that the key genes played a key role in carcinogenesis, metastasis and tumor immunity in PCa by comprehensive analysis. In addition, cellular experiments and immunohistochemistry confirmed that overexpression of RELA significantly inhibited the proliferation and migration of PCa cells, and RELA was significantly low-expression in bone metastasis. Finally, the constructed nomogram showed excellent predictive performance in Receiver Operating Characteristic (ROC, AUC = 0.99) curve, calibration curve, and Decision Curve Analysis (DCA) curve; and the targeted drugs showed good molecular docking effects.

Conclusion

In sum, this study not only provides a new theoretical basis for the mechanism of PCa bone metastasis, but also provides novel therapeutic targets and novel diagnostic tools for advanced PCa treatment.

Real-World Experience with 177Lu-PSMA-617 Radioligand Therapy After Food and Drug Administration Approval

We report our initial real-world experience with 177Lu-PSMA-617 radioligand therapy. Methods: We performed a retrospective review of patients treated with 177Lu-PSMA-617. Pretreatment PSMA PET, laboratory findings, overall survival, a fall in prostate-specific antigen by 50% (PSA50), and toxicities were evaluated. Results: Ninety-nine patients were included. Sixty patients achieved a PSA50. Seven of 18 (39%) patients who did not meet the TheraP PSMA imaging criteria achieved a PSA50. Nineteen of 31 (61%) patients who did not meet the VISION laboratory criteria achieved a PSA50. Sixty-three patients had a delay or stoppage in therapy, which was due to a good response in 19 patients and progressive disease in 14 patients. Of 10 patients with a good response who restarted treatment, 9 subsequently achieved a PSA50 on retreatment. The most common toxicities were anemia (33%) and thrombocytopenia (21%). Conclusion: At our center, patients who did not meet the TheraP PSMA imaging criteria or the VISION laboratory criteria benefited from 177Lu-PSMA-617 radioligand therapy.

Impact of Circulating Tumor Cell-Expressed Prostate-Specific Membrane Antigen and Prostate-Specific Antigen Transcripts in Different Stages of Prostate Cancer

PURPOSE

Prostate-specific membrane antigen (PSMA)-based images, which visually quantify PSMA expression, are used to determine prostate cancer micrometastases. This study evaluated whether a circulating tumor cell (CTC)-based transcript platform, including PSMA mRNA, could help identify potential prognostic markers in prostate cancer.

EXPERIMENTAL DESIGN

We prospectively enrolled 21 healthy individuals and 247 patients with prostate cancer [localized prostate cancer (LPCa), n = 94; metastatic hormone-sensitive prostate cancer (mHSPC), n = 44; and metastatic castration-resistant prostate cancer (mCRPC), n = 109]. The mRNA expression of six transcripts [PSMA, prostate-specific antigen (PSA), AR, AR-V7, EpCAM, and KRT 19] from CTCs was measured, and their relationship with biochemical recurrence (BCR) in LPCa and mCRPC progression-free survival (PFS) rate in mHSPC was assessed. PSA-PFS and radiological-PFS were also calculated to identify potential biomarkers for predicting androgen receptor signaling inhibitor (ARSI) and taxane-based chemotherapy resistance in mCRPC.

RESULTS

CTC detection rates were 75.5%, 95.3%, and 98.0% for LPCa, mHSPC, and mCRPC, respectively. In LPCa, PSMA [hazard ratio (HR), 3.35; P = 0.028) and PSA mRNA (HR, 1.42; P = 0.047] expressions were associated with BCR. Patients with mHSPC with high PSMA (HR, 4.26; P = 0.020) and PSA mRNA (HR, 3.52; P = 0.042) expressions showed significantly worse mCRPC-PFS rates than those with low expression. Increased PSA and PSMA mRNA expressions were significantly associated with shorter PSA-PFS and radiological PFS in mCPRC, indicating an association with drug resistance.

CONCLUSIONS

PSMA and PSA mRNA expressions are associated with BCR in LPCa. In advanced prostate cancer, PSMA and PSA mRNA can also predict rapid progression from mHSPC to mCRPC and ARSI or taxane-based chemotherapy resistance.

Spatial distribution of tumor-associated macrophages in an orthotopic prostate cancer mouse model

Mounting evidence suggests that the immune landscape within prostate tumors influences progression, metastasis, treatment response, and patient outcomes. In this study, we investigated the spatial density of innate immune cell populations within NOD.SCID orthotopic prostate cancer xenografts following microinjection of human DU145 prostate cancer cells. Our laboratory has previously developed nanoscale liposomes that attach to leukocytes via conjugated E-selectin (ES) and kill cancer cells via TNF-related apoptosis inducing ligand (TRAIL). Immunohistochemistry (IHC) staining was performed on tumor samples to identify and quantify leukocyte infiltration for different periods of tumor growth and E-selectin/TRAIL (EST) liposome treatments. We examined the spatial-temporal dynamics of three different immune cell types infiltrating tumors using QuPath image analysis software. IHC staining revealed that F4/80+ tumor-associated macrophages (TAMs) were the most abundant immune cells in all groups, irrespective of time or treatment. The density of TAMs decreased over the course of tumor growth and decreased in response to EST liposome treatments. Intratumoral versus marginal analysis showed a greater presence of TAMs in the marginal regions at 3 weeks of tumor growth which became more evenly distributed over time and in tumors treated with EST liposomes. TUNEL staining indicated that EST liposomes significantly increased cell apoptosis in treated tumors. Additionally, confocal microscopy identified liposome-coated TAMs in both the core and periphery of tumors, highlighting the ability of liposomes to infiltrate tumors by "piggybacking" on macrophages. The results of this study indicate that TAMs represent the majority of innate immune cells within NOD.SCID orthotopic prostate tumors, and spatial density varies widely as a function of tumor size, duration of tumor growth, and treatment of EST liposomes.

Safety Analyses of the Phase 3 VISION Trial of [177Lu]Lu-PSMA-617 in Patients with Metastatic Castration-resistant Prostate Cancer

BACKGROUND AND OBJECTIVE

[177Lu]Lu-PSMA-617 (177Lu-PSMA-617) plus the standard of care (SoC) significantly improved overall survival and radiographic progression-free survival versus SoC alone in patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer in the VISION trial. We evaluated the safety of additional cycles of 177Lu-PSMA-617 and the impact of longer observation time for patients receiving 177Lu-PSMA-617 plus SoC.

METHODS

VISION was an international, open-label study. Patients were randomised 2:1 to receive 177Lu-PSMA-617 plus SoC or SoC alone. The incidence of treatment-emergent adverse events (TEAEs) was assessed in prespecified subgroups of patients who received ≤4 cycles versus 5-6 cycles of treatment and during each cycle of treatment. The TEAE incidence was also adjusted for treatment exposure to calculate the incidence per 100 patient-treatment years of observation. This analysis was performed for the first occurrence of TEAEs.

KEY FINDINGS AND LIMITATIONS

The any-grade TEAE incidence was similar in cycles 1-4 and cycles 5-6. TEAE frequency was similar across all cycles of 177Lu-PSMA-617 treatment. No additional safety concerns were reported for patients who received >4 cycles. The exposure-adjusted safety analysis revealed that the overall TEAE incidence was similar between arms, but distinct trends for different TEAE types were noted and the incidence of events associated with 177Lu-PSMA-617 remained higher in the 177Lu-PSMA-617 arm.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Longer exposure to 177Lu-PSMA-617 plus SoC was not associated with a higher toxicity risk, and the extended time for safety observation could account for the higher TEAE incidence in comparison to SoC alone. The findings support a favourable benefit-risk profile for 6 cycles of 177Lu-PSMA-617 in this setting and the use of up to 6 cycles of 177Lu-PSMA-617 in patients who are clinically benefiting from and tolerating this therapy.

PATIENT SUMMARY

For patients with metastatic prostate cancer no longer responding to hormone therapy, an increase in the number of cycles of treatment with a radioactive compound called 177Lu-PSMA-617 from four to six had no additional adverse side effects.

PARP Inhibitors in the Treatment of Prostate Cancer: From Scientific Rationale to Clinical Development

Prostate cancer (PC) treatment has reached a milestone with the introduction of poly(ADP-ribose) polymerase (PARP) inhibitors. PARP inhibitors (PARPi) induce breaks in single-stranded and/or double-stranded DNA, resulting in synthetic lethality in cancer cells lacking functional homologous recombination genes. Around 20% to 25% of patients with metastatic castration-resistant prostate cancer harbor mutations in DNA damage repair genes, either somatic or germline. The success of PARPi in these patients has prompted studies exploring its potential in tumors classified as "BRCAness," which refers to tumors without germline BRCA1 or BRCA2 mutations. Additionally, there is a proposed connection between androgen receptor signaling and synthetic lethality of PARPi. The inclusion of genetic mutation tests in the treatment algorithm for PC is a significant step towards precision and personalized medicine, marking a first in the field. The objectives of this review encompass understanding the mechanism of action of PARPi in both monotherapy and combination therapy, exploring patient selection criteria, discussing pivotal studies that led to its approval, and offering future prospects. However, numerous unanswered questions remain, including the identification of the patient population that could benefit most from PARPi, determining whether to use PARPi as monotherapy or in combination, and finding the optimal timing of PARPi administration in advanced or localized disease. To address these questions, several ongoing clinical trials are being conducted.

Treatment Patterns and Clinical Outcomes Among Patients With Metastatic Prostate Cancer Harboring Homologous Recombination Repair Mutations

BACKGROUND

There is currently limited literature assessing the real-world treatment patterns and clinical outcomes of patients with metastatic castration-resistant prostate cancer (mCRPC) and homologous recombination repair (HRR) mutations.

METHODS

Medical charts were abstracted for mCRPC patients with ≥ 1 of 12 HRR somatic gene alterations treated at US oncology centers participating in the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange. Treatment patterns and clinical outcomes were assessed from the initiation of first-line or later (1L+) mCRPC therapy received on or after July 1, 2014.

RESULTS

Among 138 patients included in the study, the most common somatic HRR mutations were CDK12 (47.8%), BRCA2 (22.5%), and ATM (21.0%). Novel hormonal therapy and taxane chemotherapy were most commonly used in 1L; taxane use increased in later lines. Median overall survival (95% confidence interval [CI]) was 36.3 (30.7-47.8) months from initiation of 1L therapy and decreased for subsequent lines. Similarly, there was a trend of decreasing progression-free survival and prostate-specific antigen response from 1L to 4L+ therapy.

CONCLUSIONS

Treatment patterns identified in this study were similar to those among patients with mCRPC regardless of tumor HRR mutation status in the literature.

ST3 beta-galactoside alpha-2,3-sialyltransferase 1 (ST3Gal1) synthesis of Siglec ligands mediates anti-tumour immunity in prostate cancer

Immune checkpoint blockade has yet to produce robust anti-cancer responses for prostate cancer. Sialyltransferases have been shown across several solid tumours, including breast, melanoma, colorectal and prostate to promote immune suppression by synthesising sialoglycans, which act as ligands for Siglec receptors. We report that ST3 beta-galactoside alpha-2,3-sialyltransferase 1 (ST3Gal1) levels negatively correlate with androgen signalling in prostate tumours. We demonstrate that ST3Gal1 plays an important role in modulating tumour immune evasion through the synthesises of sialoglycans with the capacity to engage the Siglec-7 and Siglec-9 immunoreceptors preventing immune clearance of cancer cells. Here, we provide evidence of the expression of Siglec-7/9 ligands and their respective immunoreceptors in prostate tumours. These interactions can be modulated by enzalutamide and may maintain immune suppression in enzalutamide treated tumours. We conclude that the activity of ST3Gal1 is critical to prostate cancer anti-tumour immunity and provide rationale for the use of glyco-immune checkpoint targeting therapies in advanced prostate cancer.

Progression-directed therapy in patients with oligoprogressive castration-resistant prostate cancer

PURPOSE

Oligoprogressive lesions are observed in a subset of patients who progress to castration-resistant prostate cancer (CRPC), while other lesions remain controlled by systemic therapy. This study evaluates the impact of progression-directed therapy (PDT) on these oligoprogressive lesions.

MATERIALS AND METHODS

This retrospective study included 40 patients diagnosed with oligoprogressive CRPC. PDT was performed for treating all progressive sites using radiotherapy. Fifteen patients received PDT using radiotherapy for all progressive sites (PDT group) while 25 had additional first-line systemic treatments (non-PDT group). In PDT group, 7 patients underwent PDT and unchanged systemic therapy (PDT-A group) and 8 patients underwent PDT with additional new line of systemic therapy on CRPC (PDT-B group). The Kaplan-Meier method was used to assess treatment outcomes.

RESULTS

The prostate specific antigen (PSA) nadir was significantly lower in PDT group compare to non-PDT group (p=0.007). A 50% PSA decline and complete PSA decline were observed in 13 patients (86.7%) and 10 patients (66.7%) of PDT group and in 18 patients (72.0%) and 11 patients (44.0%) of non-PDT group, respectively. The PSA-progression free survival of PDT-B group was significantly longer than non-PDT group. The median time to failure of first-line systemic therapy on CRPC was 30.2 months in patients in PDT group and 14.9 months in non-PDT group (p=0.014). PDT-B group showed a significantly longer time to progression than non-PDT group (p=0.025). Minimal PDT-related adverse events were observed.

CONCLUSIONS

PDT can delay progression of disease and enhance treatment efficacy with acceptable tolerability in oligoprogressive CRPC.

Nanotherapeutics for prostate cancer treatment: A comprehensive review

Prostate cancer (PCa) is the most prevalent solid organ malignancy and seriously affects male health. The adverse effects of prostate cancer therapeutics can cause secondary damage to patients. Nanotherapeutics, which have special targeting abilities and controlled therapeutic release profiles, may serve as alternative agents for PCa treatment. At present, many nanotherapeutics have been developed to treat PCa and have shown better treatment effects in animals than traditional therapeutics. Although PCa nanotherapeutics are highly attractive, few successful cases have been reported in clinical practice. To help researchers design valuable nanotherapeutics for PCa treatment and avoid useless efforts, herein, we first reviewed the strategies and challenges involved in prostate cancer treatment. Subsequently, we presented a comprehensive review of nanotherapeutics for PCa treatment, including their targeting methods, controlled release strategies, therapeutic approaches and mechanisms. Finally, we proposed the future prospects of nanotherapeutics for PCa treatment.

GRP78 promotes bone metastasis of prostate cancer by regulating bone microenvironment through Sonic hedgehog signaling

Bone metastasis is the leading cause of tumor-related deaths in patients with prostate cancer (PCa). The interactions between PCa and the bone microenvironment form a vicious cycle. However, the complex molecular mechanism by which PCa regulates the bone microenvironment remains unclear. To determine the role of glucose-regulated protein (GRP78) in bone metastasis and growth, we established intracardiac injection and tibial injection models, and performed their histological staining. To assess the effect of GRP78 on the differentiation of osteoblasts and osteoclasts, we performed cell co-culture, enzyme-linked immunosorbent assay, alizarin red staining, and tartrate-resistant acid phosphatase staining. We found that GRP78 is upregulated in PCa tissues and that its upregulation is associated with PCa progression in patients. Functional experiments showed that GRP78 overexpression in PCa cells considerably promotes bone metastasis and induces bone microstructure changes. Silencing GRP78 substantially inhibits the migration and invasion of PCa cells in vitro and bone metastasis and tumor growth in vivo. Mechanistically, GRP78 promotes the migration and invasion of PCa cells via the Sonic hedgehog (Shh) signaling pathway. Cell co-culture showed that GRP78 promotes the differentiation of osteoblasts and osteoclasts through Shh signaling. Our findings suggest that tumor-bone matrix interactions owing to GRP78-activated paracrine Shh signaling by PCa cells regulate the differentiation of osteoblasts and osteoclasts. This process promotes bone metastasis and the proliferation of PCa cells in the bone microenvironment. Targeting the GRP78/Shh axis can serve as a therapeutic strategy to prevent bone metastasis and improve the quality of life of patients with PCa.

PrLZ regulates EMT and invasion in prostate cancer via the TGF-β1/p-smad2/miR-200 family/ZEB1 axis

BACKGROUND

Prostate leucine zipper (PrLZ) is a prostate-specific protein, and our previous study demonstrated that PrLZ enhances the malignant progression of prostate cancer (Pca). However, the roles of PrLZ in epithelial to mesenchymal transition (EMT) remain unknown.

METHODS

Quantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) staining, hematoxylin-eosin (HE) staining, and western blotting were used to analyze the expression of protein and genes level in human PCa cell lines. Invasion assay was used to examine the effect of PrLZ, miR-200a, miR-200b, miR-200c, miR-141, miR-429, miR-205, and ZEB1 on PCa cell line invasion in vitro. Prostate cancer metastasis animal model was designed to assess the effect of PrLZ on PCa cell line invasion in vivo.

RESULTS

We proved that high PrLZ expression initiates EMT, which was shown by the downregulation of E-cadherin and upregulation of vimentin in PC-3/PrLZ and ARCaP-E/PrLZ cells. Mechanistic analysis revealed that PrLZ regulates EMT by activating TGF-β1/p-smad2 signaling and further inhibiting the expression of miR-200 family members, which negatively regulates ZEB1 expression and causes EMT in Pca. Moreover, using two of orthotopic mouse model and tail vein injection of human prostate cancer cells mouse model, we observed that PC-3/PrLZ cells led to the development of distant organ metastases in vivo.

CONCLUSIONS

Our results show the mechanism by which PrLZ regulates EMT and metastasis and suggest that PrLZ may be a potential therapeutic target for Pca metastasis.

Pretreatment level of serum sialic acid predicts both qualitative and quantitative bone metastases of prostate cancer

Background

Recently, serum sialic acid (SA) has emerged as a distinct prognostic marker for prostate cancer (PCa) and bone metastases, warranting differential treatment and prognosis for low-volume (LVD) and high-volume disease (HVD). In clinical settings, evaluating bone metastases can prove advantageous.

Objectives

We aimed to establish the correlation between SA and both bone metastasis and HVD in newly diagnosed PCa patients.

Methods

We conducted a retrospective analysis of 1202 patients who received a new diagnosis of PCa between November 2014 and February 2021. We compared pretreatment SA levels across multiple groups and investigated the associations between SA levels and the clinical parameters of patients. Additionally, we compared the differences between HVD and LVD. We utilized several statistical methods, including the non-parametric Mann-Whitney U test, Spearman correlation, receiver operating characteristic (ROC) curve analysis, and logistic regression.

Results

The results indicate that SA may serve as a predictor of bone metastasis in patients with HVD. ROC curve analysis revealed a cut-off value of 56.15 mg/dL with an area under the curve of 0.767 (95% CI: 0.703-0.832, P < 0.001) for bone metastasis versus without bone metastasis and a cut-off value of 65.80 mg/dL with an area under the curve of 0.766 (95% CI: 0.644-0.888, P = 0.003) for HVD versus LVD. Notably, PCa patients with bone metastases exhibited significantly higher SA levels than those without bone metastases, and HVD patients had higher SA levels than LVD patients. In comparison to the non-metastatic and LVD cohorts, the cohort with HVD exhibited higher levels of alkaline phosphatase (AKP) (median, 122.00 U/L), fibrinogen (FIB) (median, 3.63 g/L), and prostate-specific antigen (PSA) (median, 215.70 ng/mL), as well as higher Gleason scores (> 7). Multivariate logistic regression analysis demonstrated that an SA level of > 56.15 mg/dL was independently associated with the presence of bone metastases in PCa patients (OR = 2.966, P = 0.018), while an SA level of > 65.80 mg/dL was independently associated with HVD (OR = 1.194, P = 0.048).

Conclusion

The pretreatment serum SA level is positively correlated with the presence of bone metastases.

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.

Organoids: An Emerging Precision Medicine Model for Prostate Cancer Research

Prostate cancer (PCa) has been known as the most prevalent cancer disease and the second leading cause of cancer mortality in men almost all over the globe. There is an urgent need for establishment of PCa models that can recapitulate the progress of genomic landscapes and molecular alterations during development and progression of this disease. Notably, several organoid models have been developed for assessing the complex interaction between PCa and its surrounding microenvironment. In recent years, PCa organoids have been emerged as powerful in vitro 3D model systems that recapitulate the molecular features (such as genomic/epigenomic changes and tumor microenvironment) of PCa metastatic tumors. In addition, application of organoid technology in mechanistic studies (i.e., for understanding cellular/subcellular and molecular alterations) and translational medicine has been recognized as a promising approach for facilitating the development of potential biomarkers and novel therapeutic strategies. In this review, we summarize the application of PCa organoids in the high-throughput screening and establishment of relevant xenografts for developing novel therapeutics for metastatic, castration resistant, and neuroendocrine PCa. These organoid-based studies are expected to expand our knowledge from basic research to clinical applications for PCa diseases. Furthermore, we also highlight the optimization of PCa cultures and establishment of promising 3D organoid models for in vitro and in vivo investigations, ultimately facilitating mechanistic studies and development of novel clinical diagnosis/prognosis and therapies for PCa.

Sanguinarine chloride induces ferroptosis by regulating ROS/BACH1/HMOX1 signaling pathway in prostate cancer

BACKGROUND

Sanguinarine chloride (S.C) is a benzophenanthrine alkaloid derived from the root of sanguinaria canadensis and other poppy-fumaria species. Studies have reported that S.C exhibits antioxidant, anti-inflammatory, proapoptotic, and growth inhibitory effects, which contribute to its anti-cancer properties. Recent studies suggested that the antitumor effect of S.C through inducing ferroptosis in some cancers. Nevertheless, the precise mechanism underlying the regulation of ferroptosis by S.C remains poorly understood.

METHODS

A small molecule library was constructed based on FDA and CFDA approved small molecular drugs. CCK-8 assay was applied to evaluate the effects of the small molecule compound on tumor cell viability. Prostate cancer cells were treated with S.C and then the cell viability and migration ability were assessed using CCK8, colony formation and wound healing assay. Reactive oxygen species (ROS) and iron accumulation were quantified through flow cytometry analysis. The levels of malondialdehyde (MDA) and total glutathione (GSH) were measured using commercially available kits. RNA-seq analysis was performed to identify differentially expressed genes (DEGs) among the treatment groups. Western blotting and qPCR were utilized to investigate the expression of relevant proteins and genes. In vivo experiments employed a xenograft mice model to evaluate the anti-cancer efficacy of S.C.

RESULTS

Our study demonstrated that S.C effectively inhibited the viability of various prostate cancer cells. Notably, S.C exhibited the ability to enhance the cytotoxicity of docetaxel in DU145 cells. We found that S.C-induced cell death partially relied on the induction of ferroptosis, which was mediated through up-regulation of HMOX1 protein. Additionally, our investigation revealed that S.C treatment decreased the stability of BACH1 protein, which contributed to HMOX1expression. We further identified that S.C-induced ROS caused BACH1 instability by suppressing USP47expression. Moreover, In DU145 xenograft model, we found S.C significantly inhibited prostate cancer growth, highlighting its potential as a therapeutic strategy. Collectively, these findings provide evidence that S.C could induce regulated cell death (RCD) in prostate cancer cells and effectively inhibit tumor growth via triggering ferroptosis. This study provides evidence that S.C effectively suppresses tumor progression and induces ferroptosis in prostate cancer cells by targeting ROS/USP47/BACH1/HMOX1 axis.

CONCLUSION

This study provides evidence that S.C effectively suppresses tumor progression and induces ferroptosis in prostate cancer cells by targeting the ROS/USP47/BACH1/HMOX1 axis. These findings offer novel insights into the underlying mechanism by which S.C inhibits the progression of prostate cancer. Furthermore, leveraging the potential of S.C in targeting ferroptosis may present a new therapeutic opportunity for prostate cancer. This study found that S.C induces ferroptosis by targeting the ROS/USP47/BACH1/HMOX1 axis in prostate cancer cells.

Protocol for Evaluating the Efficacy and Safety of Radiotherapy for Prostate and Oligometastatic Lesions in Patients With Low-Burden Sensitive Oligometastatic Prostate Cancer: An Open, Exploratory Pilot Clinical Trial

INTRODUCTION

The existing large prospective study demonstrates the benefits of primary radiotherapy in patients with low-volume oligometastatic prostate cancer (OMPC), and there is additional evidence of the benefits of local metastasis-directed therapy (MDT) for metastatic lesions. However, there are no results from a prospective study to demonstrate the efficacy of radiotherapy for prostate and oligometastases. Therefore, the aim of the protocol is to illustrate the efficacy of radiotherapy for prostate and oligometastatic lesions in patients with low-volume de novo hormone-sensitive OMPC.

METHODS AND ANALYSIS

This study involves a prospective, single-center, limited-sample, single-arm exploration of radiotherapy for prostate and oligometastatic lesions in patients diagnosed with low-volume hormone-sensitive OMPC. Eligible participants undergo thorough assessments and treatment involving endocrine therapy alongside radiation targeting metastatic lesions and the pelvic region. The primary site is treated with volumetric modulated arc therapy (VMAT), while metastatic sites are treated with either VMAT or stereotactic body radiation therapy (SBRT) depending on their location. All patients received radiation therapy for both the primary and metastatic lesions combined with endocrine therapy. Endocrine therapy with an antiandrogen (bicalutamide, for 4 weeks) androgen deprivation therapy combined with novel hormonal agents (acetate abiraterone) will be continued for 2 years. The primary objective is to evaluate progression-free survival-2 (PFS-2), while secondary endpoints include androgen deprivation therapy (ADT)-free survival, quality of life (QoL), overall survival, time to castration-resistant prostate cancer (CRPC), radiation-related complications, and endocrine therapy-related adverse events.

ETHICS AND DISSEMINATION

Approval was obtained from the ethics committee of the First Affiliated Hospital of Naval Medical University (CHEC2023-220). This is a single-arm exploration pilot trial evaluating radiotherapy for prostate and oligometastatic lesions in patients with OMPC. It aims to disseminate its findings through peer-reviewed journals and relevant medical conferences, with the intention of publication and presentation at these events.

TRIAL REGISTRATION NUMBERS

Clinicaltrials.gov identifier NCT06198387.

Risk factors of foot ulcers in patients with end-stage renal disease on dialysis: A meta-analysis

The present study aims to assess the risk factors for foot ulcers in patients undergoing dialysis for end-stage renal disease (ESRD) and to provide evidence-based guidance for prevention and treatment. A systematic search was conducted on PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Chinese Biomedical Literature Database and Wanfang Data from the database inception until May 2023 to identify relevant studies investigating the risk factors for foot ulcers in dialysis patients with ESRD. Two independent researchers conducted the literature screening and data extraction. The meta-analysis was performed using STATA 17.0 software. Ultimately, six articles comprising 1620 patients were included for analysis. The meta-analysis revealed that male (OR, 1.464; 95% CI: 1.082-1.980, p = 0.013), hypertension (OR, 1.781; 95% CI: 1.293-2.4550, p < 0.001), peripheral artery disease (PAD) (OR, 5.014; 95% CI: 2.514-9.998, p < 0.001), type 1 diabetes mellitus (T1DM) (OR, 2.993; 95% CI: 1.477-6.065, p = 0.002) and type 2 diabetes mellitus (T2DM) (OR, 2.498; 95% CI:1.466-4.256, p = 0.001) were risk factors for foot ulcers in dialysis patients with ESRD. Conversely, the female sex (OR, 0.683; 95% CI: 0.505-0.924, p = 0.013) was a protective factor against foot ulcers. Our analysis revealed that male sex, hypertension, PAD, T1DM and T2DM were risk factors for foot ulcers in patients undergoing dialysis for ESRD. Conversely, the female sex was a protective factor against foot ulcers. Therefore, it is crucial to strengthen health education that targets patients with these risk factors and regularly screen high-risk individuals. Early detection and treatment can help delay disease progression.

Gastrodin inhibits prostate cancer proliferation by targeting canonical Wnt/β-catenin signaling pathway

Prostate cancer is an epithelial malignant tumor occurring in the prostate and is the most common malignant tumor in the male genitourinary system. In recent years, the incidence of prostate cancer in China has shown a trend of sudden increase. The search for new and effective drugs to treat prostate cancer is therefore extremely important.The canonical Wnt/β-catenin signaling pathway has been shown to be involved in the regulation of tumor proliferation, migration and differentiation. Activation of the canonical Wnt/β-Catenin signaling pathway in the prostate has oncogenic effects. Drugs targeting the canonical Wnt/β-catenin signaling pathway have great potential in the treatment of prostate cancer. In this study, we found that Gastrodin could significantly inhibit the proliferation of prostate cancer cell line PC3 and DU145. Oral administration Gastrodin could significantly inhibit the tumor growth of PC3 cells subcutaneously injected. Gastrodin has an inhibitory effect on canonical Wnt/β-Catenin signaling pathway in Prostate cancer, and this inhibitory effect can be abolished by Wnt/β-Catenin agonist LiCl. These findings raise the possibility that Gastrodin can be used in the treatment of Prostate cancer by targeting canonical Wnt/β-Catenin signaling pathway.

Fascin-1 expression is associated with neuroendocrine prostate cancer and directly suppressed by androgen receptor

BACKGROUND

Neuroendocrine prostate cancer (NEPC) is an aggressive form of prostate cancer, arising from resistance to androgen-deprivation therapies. However, the molecular mechanisms associated with NEPC development and invasiveness are still poorly understood. Here we investigated the expression and functional significance of Fascin-1 (FSCN1), a pro-metastasis actin-bundling protein associated with poor prognosis of several cancers, in neuroendocrine differentiation of prostate cancer.

METHODS

Differential expression analyses using Genome Expression Omnibus (GEO) database, clinical samples and cell lines were performed. Androgen or antagonist's cellular treatments and knockdown experiments were used to detect changes in cell morphology, molecular markers, migration properties and in vivo tumour growth. Chromatin immunoprecipitation-sequencing (ChIP-Seq) data and ChIP assays were analysed to decipher androgen receptor (AR) binding.

RESULTS

We demonstrated that FSCN1 is upregulated during neuroendocrine differentiation of prostate cancer in vitro, leading to phenotypic changes and NEPC marker expression. In human prostate cancer samples, FSCN1 expression is restricted to NEPC tumours. We showed that the androgen-activated AR downregulates FSCN1 expression and works as a transcriptional repressor to directly suppress FSCN1 expression. AR antagonists alleviate this repression. In addition, FSCN1 silencing further impairs in vivo tumour growth.

CONCLUSION

Collectively, our findings identify FSCN1 as an AR-repressed gene. Particularly, it is involved in NEPC aggressiveness. Our results provide the rationale for the future clinical development of FSCN1 inhibitors in NEPC patients.

CircDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis

Prostate cancer is the most prevalent type of cancer among men worldwide. The importance of circular RNA (circRNA) in prostate cancer and its connection to malignancy has been steadily recognized. circRNA expression was obtained by circRNA sequencing of prostate cancer. circRNA and its function were further analysed. The results were verified by qRT-PCR, RIP assay, FISH, RNA pulldown, WB, CCK-8, colony formation assay and wound-healing assay. BALB/c Nude mice were used for xenograft hosts. Low expression of circDHRS3 was assessed in prostate cancer. Overexpression of circDHRS3 inhibited prostate cancer growth and migration in vitro. Additionally, miR-421 was shown to be the downstream target of circDHRS3, as shown by fluorescence in situ hybridization and dual-luciferase experiments. The rescue assay results for the PC3 and Du145 cell lines demonstrated that circDHRS3 inhibits prostate cancer cell lines' ability to proliferate and metastasize by modulating MEIS2 expression through the circDHRS3/miR-421/MEIS2 axis. In vivo investigations confirmed that the overexpression of circDHRS3 could inhibit both the lung and bone metastasis of prostate cancer cells. circDHRS3 has the potential to become a biomarker and a targeted therapeutic site for prostate cancer, particularly in the malignant stage. Our study indicates that circDHRS3 inhibits prostate cancer cell proliferation and metastasis through the circDHRS3/miR-421/MEIS2 axis.

New Therapeutic Perspectives in Prostate Cancer: Patient-Derived Organoids and Patient-Derived Xenograft Models in Precision Medicine

One of the major goals in the advancement of basic cancer research focuses on the development of new anticancer therapies. To understand the molecular mechanisms of cancer progression, acquired drug resistance, and the metastatic process, the use of preclinical in vitro models that faithfully summarize the properties of the tumor in patients is still a necessity. The tumor is represented by a diverse group of cell clones, and in recent years, to reproduce in vitro preclinical tumor models, monolayer cell cultures have been supplanted by patient-derived xenograft (PDX) models and cultured organoids derived from the patient (PDO). These models have proved indispensable for the study of the tumor microenvironment (TME) and its interaction with tumor cells. Prostate cancer (PCa) is the most common neoplasia in men in the world. It is characterized by genomic instability and resistance to conventional therapies. Despite recent advances in diagnosis and treatment, PCa remains a leading cause of cancer death. Here, we review the studies of the last 10 years as the number of papers is growing very fast in the field. We also discuss the discovered limitations and the new challenges in using the organoid culture system and in using PDXs in studying the prostate cancer phenotype, performing drug testing, and developing anticancer molecular therapies.

Hematological Toxicities with PARP Inhibitors in Prostate Cancer: A Systematic Review and Meta-Analysis of Phase II/III Randomized Controlled Trials

BACKGROUND

Poly ADP-ribose polymerase inhibitors (PARPis) are an important class of therapeutics for metastatic castration-resistant prostate cancer (mCRPC). Unlike hormone-based treatments for mCRPC, PARPis are not without drug-related hematological adverse events.

OBJECTIVE

To review the evidence on hematological toxicities, including anemia, thrombocytopenia, and neutropenia from PARPis in prostate cancer.

STUDY METHODOLOGY

A systematic review and meta-analysis using the PRISMA guidelines was performed for phase II and III randomized controlled trials (RCTs) of PARPis in prostate cancer. PubMed, Embase, and Ovid All EBM reviews-Cochrane were queried from inception to 9 June 2023. The Mantel-Haenszel method was used to report risk ratios (RR) and 95% confidence intervals (CI) for all-grade and high-grade anemia, thrombocytopenia, and neutropenia toxicities.

RESULTS

The systematic review retrieved eight phase II and III RCTs; specifically, eight were included in the anemia, five in the all-grade thrombocytopenia and neutropenia, and four in the high-grade thrombocytopenia and neutropenia outcomes. Compared to a placebo and/or other non-PARPi treatments, PARPi use was associated with an increased risk of all-grade anemia (RR, 3.37; 95% CI, 2.37-4.79; p < 0.00001), thrombocytopenia (RR, 4.54; 95% CI, 1.97-10.44; p = 0.0004), and neutropenia (RR, 3.11; 95% CI, 1.60-6.03; p = 0.0008). High-grade anemia (RR, 6.94; 95% CI, 4.06-11.86; p < 0.00001) and thrombocytopenia (RR, 5.52; 95% CI, 2.80-10.88; p < 0.00001) were also associated with an increased risk, while high-grade neutropenia (RR, 3.63; 95% CI, 0.77-17.23; p = 0.10) showed no significant association. Subgroup stratification analyses showed differences in various all-grade and high-grade toxicities.

CONCLUSION

PARPis were associated with an increased risk of hematological AEs. Future studies with more pooled RCTs will enhance this understanding and continue to inform patient-physician shared decision-making. Future studies may also have a role in improving the current management strategies for these AEs.

Potential agnostic role of BRCA alterations in patients with several solid tumors: One for all, all for one?

Germline BRCA1/2 alterations in the Homologous Recombination (HR) pathway are considered as main susceptibility biomarkers to Hereditary Breast and Ovarian Cancers (HBOC). The modern molecular biology technologies allowed to characterize germline and somatic BRCA1/2 alterations in several malignancies, broadening the landscape of BRCA1/2-alterated tumors. In the last years, BRCA genetic testing, beyond the preventive value, also assumed a predictive and prognostic significance for patient management. The approval of molecules with agnostic indication is leading to a new clinical model, defined "mutational". Among these drugs, the Poly (ADP)-Ribose Polymerase inhibitors (PARPi) for BRCA1/2-deficient tumors were widely studied leading to increasing therapeutic implications. In this Review we provided an overview of the main clinical studies describing the association between BRCA-mutated tumors and PARPi response, focusing on the controversial evidence about the potential agnostic indication based on BRCA1/2 alterations in several solid tumors.

Real-World Treatment Patterns Among French Patients With Metastatic Castration-Resistant Prostate Cancer Under Abiraterone or Enzalutamide

PURPOSE

Using large French retrospective study cohort of chemotherapy-naïve metastatic castration-resistant prostate cancer patients (mCRPC; n = 10,308) comparing survival between patients who initiated abiraterone (ABI; 64%) and those initiating enzalutamide (ENZ; 36%), the present objective was to describe treatment patterns in the 2 years following initiation.

METHOD

Using the national health data system (SNDS) from 2014 to 2018, we first explored the number of treatment lines, and secondly, patterns of patient management using state sequence analysis; cluster analyses were performed on the 0 to 12 month and 13 to 24 month periods. Age, Charlson score, and duration of androgen deprivation therapy (ADT) were obtained for each cluster in the first year of follow-up.

RESULTS

Patients with only 1 treatment line accounted for 52%. In the 0 to 12 month sequence analysis, the main clusters among ABI/ENZ new users involved patients who continued the initial treatment (54% of 65% respectively) and discontinued active treatment (14.5% for both). Less than 2 years exposure to ADT prior to ABI/ENZ initiation was frequently observed for noncontrolled mCRPC, as shown in the death and switch from ABI/ENZ to docetaxel clusters. The clusters for a switch ABI/ENZ to ENZ/ABI involved 6% to 11% of the patients.

CONCLUSION

Our study suggested fairly similar patterns between ABI and ENZ initiation. The cluster of patients with active treatment discontinuation needs to be further investigated, as well as factors influencing therapeutic choice. Better understanding for the use of second-generation hormone therapy in mCRPC in real life, could improve its implementation by clinicians in the early stages of prostate cancer.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

m6A-modified circABCC4 promotes stemness and metastasis of prostate cancer by recruiting IGF2BP2 to increase stability of CCAR1

Prostate cancer (PCa) is a malignant tumor of the urinary system. CircABCC4 has been demonstrated to promote the development of PCa; however, its regulatory mechanisms in PCa progression remain largely unknown. We found that circABCC4 was highly expressed in PCa tissues and cells, and elevated circABCC4 level indicated a poor overall survival of PCa patients. METTL3 overexpression increased circABCC4 expression via m6A modification in PCa cells. Functionally, knockdown of circABCC4 or METTL3 repressed PCa cell stemness, migration, and invasion in vitro and delayed PCa cancer growth and metastasis in vivo. circABCC4 knockdown-mediated inhibition in PCa cell stemness and metastasis could be counteracted by overexpression of wild-type circABCC4 with m6A sites. Mechanistically, circABCC4 recruited IGF2BP2 protein to CCAR1 mRNA, thereby enhancing CCAR1 mRNA stability and subsequent activation of the Wnt/β-catenin pathway. Overexpression of CCAR1 counteracted the inhibitory effect of circABCC4 silencing on PCa cell stemness and metastasis. These results revealed that m6A-modified circABCC4 by METTL3 facilitated PCa cell stemness and metastasis by interacting with IGF2BP2 to increase the stability and expression of CCAR and subsequent expression of Wnt/β-catenin target genes. Our findings suggest circABCC4 as a promising therapeutic target for PCa.

A Phase Ib, Open-label Study Evaluating the Safety and Efficacy of Ipatasertib plus Rucaparib in Patients with Metastatic Castration-resistant Prostate Cancer

PURPOSE

To report the safety and efficacy of ipatasertib (AKT inhibitor) combined with rucaparib (PARP inhibitor) in patients with metastatic castration-resistant prostate cancer (mCRPC) previously treated with second-generation androgen receptor inhibitors.

PATIENTS AND METHODS

In this two-part phase Ib trial (NCT03840200), patients with advanced prostate, breast, or ovarian cancer received ipatasertib (300 or 400 mg daily) plus rucaparib (400 or 600 mg twice daily) to assess safety and identify a recommended phase II dose (RP2D). A part 1 dose-escalation phase was followed by a part 2 dose-expansion phase in which only patients with mCRPC received the RP2D. The primary efficacy endpoint was prostate-specific antigen (PSA) response (≥50% reduction) in patients with mCRPC. Patients were not selected on the basis of tumor mutational status.

RESULTS

Fifty-one patients were enrolled (part 1 = 21; part 2 = 30). Ipatasertib 400 mg daily plus rucaparib 400 mg twice daily was the selected RP2D, received by 37 patients with mCRPC. Grade 3/4 adverse events occurred in 46% (17/37) of patients, with one grade 4 adverse event (anemia, deemed related to rucaparib) and no deaths. Adverse events leading to treatment modification occurred in 70% (26/37). The PSA response rate was 26% (9/35), and the objective response rate per Response Criteria in Solid Tumors (RECIST) 1.1 was 10% (2/21). Median radiographic progression-free survival per Prostate Cancer Working Group 3 criteria was 5.8 months [95% confidence interval (CI), 4.0-8.1], and median overall survival was 13.3 months (95% CI, 10.9-not evaluable).

CONCLUSIONS

Ipatasertib plus rucaparib was manageable with dose modification but did not demonstrate synergistic or additive antitumor activity in previously treated patients with mCRPC.

The role of cytoreductive radical prostatectomy and lymph node dissection in bone-metastatic prostate cancer: A population-based study

BACKGROUNDS

The role of cytoreductive radical prostatectomy (cRP) for bone-metastatic prostate cancer (bmPCa) remains controversial. We aimed to figure out whether cRP and lymph node dissection (LND) can benefit bmPCa.

METHODS

11,271 PCa patients with bone metastatic burden from 2010 to 2019 were identified using SEER-Medicare. Overall survival (OS) and cancer-specific survival (CSS) rates were visualized using Kaplan-Meier plots. Multivariable Cox regression analyses were constructed to examine the effects of cRP and LND on survival, after stratifying to age, prostate specific antigen (PSA), clinical stages, Gleason score, metastatic burden, radiotherapy, and chemotherapy status.

RESULTS

317 PCa patients underwent cRP and cRP was increasingly performed for bmPCa from 2010 (2.2%) to 2019 (3.0%) (p < 0.05). In multi analyses, cRP was predisposed to a better OS or CSS in patients with age < 75, PSA < 98 ng/mL, bone-only metastatic sites or patients not receiving chemotherapy (all p < 0.05). For the patients undergoing cRP, LND especially extended LND was associated with a better OS or CSS (all p < 0.05).

CONCLUSIONS

cRP might benefit OS or CSS in young patients with low PSA and bone-only metastatic sites not receiving chemotherapy. And a clear OS or CSS benefit of LND especially extended LND was observed in patients undergoing cRP.

Lutetium-177 PSMA for the treatment of metastatic castrate resistant prostate cancer: a systematic review

INTRODUCTION

Metastatic castrate resistant prostate cancer (mCPRC) remains an aggressive form of prostate cancer that no longer responds to traditional hormonal treatment alone. Despite the advent of novel anti-androgen medications, many patients continue to progress, and as a result, there is a growing need for additional treatment options.

AREAS COVERED

Lutetium-177 (177Lu) - PSMA-617 has become one of the new frontline treatment options for refractory metastatic castrate resistant prostate cancer after the failure of novel anti-androgen therapy and chemotherapy. Lu-177 has been used in real-world prospective trials and is now becoming utilized in newer phase III clinical trials. Here, we present a comprehensive overview of the current literature, covering retrospective studies, prospective studies, and clinical trials that established Lutetium-177-PSMA-617 (177Lu-PSMA-617) for the treatment of mCRPC.

EXPERT OPINION

177Lu - PSMA-617 has been approved for treatment of mCRPC based on positive phase III studies. While this treatment is tolerable and effective, biomarkers are necessary to determine which patients will benefit. In the future, radioligand treatments will likely be utilized in earlier lines of therapy and potentially in combination with other prostate cancer treatments.

Chemotherapy for the initial treatment of metastatic prostate adenocarcinoma and neuroendocrine carcinoma at diagnosis: real world application and impact in the SEER database (2004 -2018)

Background

Randomized controlled phase III trials have reported significant improvements in disease response and survival with the addition of chemotherapy to androgen deprivation therapy for men presenting with metastatic prostate cancer. We examined the implementation of such knowledge and its impact within the Surveillance, Epidemiology, and End Results (SEER) database.

Method

The administration of chemotherapy for men with an initial presentation of metastatic prostate cancer from 2004 to 2018 in the SEER database and its association with survival outcomes was examined. Kaplan-Meier estimates were applied to compare survival curves. Cox proportion hazard survival models were used to analyze the association of chemotherapy and other variables with both cancer- specific and overall survival.

Result

A total of 727,804 patients were identified with 99.9% presenting with adenocarcinoma and 0.1% with neuroendocrine histopathology. Chemotherapy as initial treatment for men with de novo distant metastatic adenocarcinoma increased from 5.8% during 2004-2013 to 21.4% during 2014-2018. Chemotherapy was associated with a poorer prognosis during 2004-2013 but was associated with improved cancer-specific (hazard ratio (HR) = 0.85, 95% confidence interval (CI): 0.78-0.93, p=0.0004) and overall survival (HR= 0.78, 95% CI: 0.71-0.85, p < 0.0001) during 2014-2018. The improved prognosis during 2014-2018 was observed in patients with visceral or bone metastasis and most impactful for patients aged 71-80 years. These findings were confirmed by subsequent propensity score matching analyses. Furthermore, chemotherapy was consistently provided to 54% of patients with neuroendocrine carcinoma at diagnosis from 2004 to 2018. Treatment was associated with improved cancer-specific survival (HR= 0.62, 95% CI: 0.45-0.87, p=0.0055) and overall survival (HR= 0.69, 95% CI: 0.51-0. 94, p=0.0176) during 2014-2018 but not significant in earlier years.

Conclusion

Chemotherapy at initial diagnosis was increasingly employed in men with metastatic adenocarcinoma after 2014 and consistent with the evolution of National Comprehensive Cancer Network (NCCN) guidelines. Benefits for chemotherapy are suggested after 2014 in the treatment of men with metastatic adenocarcinoma. The use of chemotherapy for neuroendocrine carcinoma at diagnosis has remained stable, and outcomes have improved in more recent years. Further development and optimization of chemotherapy continues to evolve for men with de novo diagnosis of metastatic prostate cancer.

Health-related quality of life and pain outcomes with [177Lu]Lu-PSMA-617 plus standard of care versus standard of care in patients with metastatic castration-resistant prostate cancer (VISION): a multicentre, open-label, randomised, phase 3 trial

BACKGROUND

In VISION, the prostate-specific membrane antigen (PSMA)-targeted radioligand therapy lutetium-177 [177Lu]Lu-PSMA-617 (vipivotide tetraxetan) improved radiographic progression-free survival and overall survival when added to protocol-permitted standard of care in patients with metastatic castration-resistant prostate cancer. Here, we report additional health-related quality of life (HRQOL), pain, and symptomatic skeletal event results.

METHODS

This multicentre, open-label, randomised, phase 3 trial was conducted at 84 cancer centres in nine countries in North America and Europe. Eligible patients were aged 18 years or older; had progressive PSMA-positive metastatic castration-resistant prostate cancer; an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2; and had previously received of at least one androgen receptor pathway inhibitor and one or two taxane-containing regimens. Patients were randomly assigned (2:1) to receive either [177Lu]Lu-PSMA-617 plus protocol-permitted standard of care ([177Lu]Lu-PSMA-617 group) or standard of care alone (control group) using permuted blocks. Randomisation was stratified by baseline lactate dehydrogenase concentration, liver metastases, ECOG performance status, and androgen receptor pathway inhibitor inclusion in standard of care. Patients in the [177Lu]Lu-PSMA-617 group received intravenous infusions of 7·4 gigabecquerel (GBq; 200 millicurie [mCi]) [177Lu]Lu-PSMA-617 every 6 weeks for four cycles plus two optional additional cycles. Standard of care included approved hormonal treatments, bisphosphonates, and radiotherapy. The alternate primary endpoints were radiographic progression-free survival and overall survival, which have been reported. Here we report the key secondary endpoint of time to first symptomatic skeletal event, and other secondary endpoints of HRQOL assessed with the Functional Assessment of Cancer Therapy-Prostate (FACT-P) and EQ-5D-5L, and pain assessed with the Brief Pain Inventory-Short Form (BPI-SF). Patient-reported outcomes and symptomatic skeletal events were analysed in all patients who were randomly assigned after implementation of measures designed to reduce the dropout rate in the control group (on or after March 5, 2019), and safety was analysed according to treatment received in all patients who received at least one dose of treatment. This trial is registered with ClinicalTrials.gov, NCT03511664, and is active but not recruiting.

FINDINGS

Between June 4, 2018, and Oct 23, 2019, 831 patients were enrolled, of whom 581 were randomly assigned to the [177Lu]Lu-PSMA-617 group (n=385) or control group (n=196) on or after March 5, 2019, and were included in analyses of HRQOL, pain, and time to first symptomatic skeletal event. The median age of patients was 71 years (IQR 65-75) in the [177Lu]Lu-PSMA-617 group and 72·0 years (66-76) in the control group. Median time to first symptomatic skeletal event or death was 11·5 months (95% CI 10·3-13·2) in the [177Lu]Lu-PSMA-617 group and 6·8 months (5·2-8·5) in the control group (hazard ratio [HR] 0·50, 95% CI 0·40-0·62). Time to worsening was delayed in the [177Lu]Lu-PSMA-617 group versus the control group for FACT-P score (HR 0·54, 0·45-0·66) and subdomains, BPI-SF pain intensity score (0·52, 0·42-0·63), and EQ-5D-5L utility score (0·65, 0·54-0·78). Grade 3 or 4 haematological adverse events included decreased haemoglobin (80 [15%] of 529 assessable patients who received [177Lu]Lu-PSMA-617 plus standard of care vs 13 [6%] of 205 who received standard of care only), lymphocyte concentrations (269 [51%] vs 39 [19%]), and platelet counts (49 [9%] vs five [2%]). Treatment-related adverse events leading to death occurred in five (1%) patients who received [177Lu]Lu-PSMA-617 plus standard of care (pancytopenia [n=2], bone marrow failure [n=1], subdural haematoma [n=1], and intracranial haemorrhage [n=1]) and no patients who received standard of care only.

INTERPRETATION

[177Lu]Lu-PSMA-617 plus standard of care delayed time to worsening in HRQOL and time to skeletal events compared with standard of care alone. These findings support the use of [177Lu]Lu-PSMA-617 in patients with metastatic castration-resistant prostate cancer who received previous androgen receptor pathway inhibitor and taxane treatment.

FUNDING

Advanced Accelerator Applications (Novartis).

Validation of an LC-MS/MS method for simultaneous quantification of abiraterone, enzalutamide and darolutamide in human plasma

Currently, several oral androgen receptor signalling inhibitors are available for the treatment of advanced prostate cancer. Quantification of plasma concentrations of these drugs is highly relevant for various purposes, such as Therapeutic Drug Monitoring (TDM) in oncology. Here, we report a liquid chromatography/tandem mass spectrometric (LC-MS/MS) method for the simultaneous quantification of abiraterone, enzalutamide, and darolutamide. The validation was performed according to the requirements of the U.S. Food and Drug Administration and European Medicine Agency. We also demonstrate the clinical applicability of the quantification of enzalutamide and darolutamide in patients with metastatic castration-resistant prostate cancer.

Practical Utility of Liquid Biopsies for Evaluating Genomic Alterations in Castration-Resistant Prostate Cancer

Traditional tissue-based assessments of genomic alterations in castration-resistant prostate cancer (CRPC) can be challenging. To evaluate the real-world clinical utility of liquid biopsies for the evaluation of genomic alterations in CRPC, we preemptively collected available plasma samples and archival tissue samples from patients that were being treated for clinically confirmed CRPC. The cell-free DNA (cfDNA) and tumor tissue DNA were analyzed using the AlphaLiquid^®100-HRR panel. Plasma samples from a total of 87 patients were included in this study. Somatic mutations from cfDNA were detected in 78 (89.7%) patients, regardless of the presence of overt metastasis or concomitant treatment given at the time of plasma sample collection. Twenty-three patients were found to have known deleterious somatic or germline mutations in HRR genes from their cfDNA. Archival tissue samples from 33 (37.9%) patients were available for comparative analysis. Tissue sequencing was able to yield an NGS result in only 51.5% of the tissue samples. The general sensitivity of cfDNA for detecting somatic mutations in tissues was 71.8%, but important somatic/germline mutations in HRR genes were found to have a higher concordance (100%). Liquid biopsies can be a reasonable substitute for tissue biopsies in CRPC patients when evaluating genomic alterations.

LSD1 Inhibition Disrupts Super-Enhancer-Driven Oncogenic Transcriptional Programs in Castration-Resistant Prostate Cancer

The lysine demethylase LSD1 (also called KDM1A) plays important roles in promoting multiple malignancies including both hematologic cancers and solid tumors. LSD1 targets histone and nonhistone proteins and can function as a transcriptional corepressor or coactivator. LSD1 has been reported to act as a coactivator of androgen receptor (AR) in prostate cancer and to regulate the AR cistrome via demethylation of its pioneer factor FOXA1. A deeper understanding of the key oncogenic programs targeted by LSD1 could help stratify prostate cancer patients for treatment with LSD1 inhibitors, which are currently under clinical investigation. In this study, we performed transcriptomic profiling in an array of castration-resistant prostate cancer (CRPC) xenograft models that are sensitive to LSD1 inhibitor treatment. Impaired tumor growth by LSD1 inhibition was attributed to significantly decreased MYC signaling, and MYC was found to be a consistent target of LSD1. Moreover, LSD1 formed a network with BRD4 and FOXA1 and was enriched at super-enhancer regions exhibiting liquid-liquid phase separation. Combining LSD1 inhibitors with BET inhibitors exhibited strong synergy in disrupting the activities of multiple drivers in CRPC, thereby inducing significant growth repression of tumors. Importantly, the combination treatment showed superior effects than either inhibitor alone in disrupting a subset of newly identified CRPC-specific super-enhancers. These results provide mechanistic and therapeutic insights for cotargeting two key epigenetic factors and could be rapidly translated in the clinic for CRPC patients.

SIGNIFICANCE

LSD1 drives prostate cancer progression by activating super-enhancer-mediated oncogenic programs, which can be targeted with the combination of LSD1 and BRD4 inhibitors to suppress the growth of CRPC.

hSSB1 (NABP2/OBFC2B) modulates the DNA damage and androgen-induced transcriptional response in prostate cancer

BACKGROUND

Activation and regulation of androgen receptor (AR) signaling and the DNA damage response impact the prostate cancer (PCa) treatment modalities of androgen deprivation therapy (ADT) and radiotherapy. Here, we have evaluated a role for human single-strand binding protein 1 (hSSB1/NABP2) in modulation of the cellular response to androgens and ionizing radiation (IR). hSSB1 has defined roles in transcription and maintenance of genome stability, yet little is known about this protein in PCa.

METHODS

We correlated hSSB1 with measures of genomic instability across available PCa cases from The Cancer Genome Atlas (TCGA). Microarray and subsequent pathway and transcription factor enrichment analysis were performed on LNCaP and DU145 prostate cancer cells.

RESULTS

Our data demonstrate that hSSB1 expression in PCa correlates with measures of genomic instability including multigene signatures and genomic scars that are reflective of defects in the repair of DNA double-strand breaks via homologous recombination. In response to IR-induced DNA damage, we demonstrate that hSSB1 regulates cellular pathways that control cell cycle progression and the associated checkpoints. In keeping with a role for hSSB1 in transcription, our analysis revealed that hSSB1 negatively modulates p53 and RNA polymerase II transcription in PCa. Of relevance to PCa pathology, our findings highlight a transcriptional role for hSSB1 in regulating the androgen response. We identified that AR function is predicted to be impacted by hSSB1 depletion, whereby this protein is required to modulate AR gene activity in PCa.

CONCLUSIONS

Our findings point to a key role for hSSB1 in mediating the cellular response to androgen and DNA damage via modulation of transcription. Exploiting hSSB1 in PCa might yield benefits as a strategy to ensure a durable response to ADT and/or radiotherapy and improved patient outcomes.

Case Report: Long-term complete response to PSMA-targeted radioligand therapy and abiraterone in a metastatic prostate cancer patient

Despite decades of research and clinical trials, metastatic castration-resistant prostate cancer (mCRPC) remains incurable and typically fatal. Current treatments may provide modest increases in progression-free survival but can come with significant adverse effects and are disaggregated from the diagnostic imaging needed to fully assess the spread of metastatic disease. A theranostic approach, using radiolabeled ligands that target the cell surface protein PSMA, simplifies the visualization and disease treatment process by enabling both to use similar agents. Here, we describe an exemplary case wherein a gentleman in his 70s with mCRPC on diagnosis was treated with 177Lu-PSMA-617 and abiraterone, and remains disease-free to date, over five years later.

Recent advances in the molecular targeted drugs for prostate cancer

CONTEXT

Prostate cancer (PCa) is the second largest male tumor in the world and one of the most common malignant tumors in the urinary system. In recent years, the incidence rate of PCa in China has been increasing year by year. Meanwhile, refractory hormone resistance and adverse drug reactions of advanced PCa cause serious harm to patients.

OBJECTIVE

The present study aims to systematically review the recent advances in molecularly targeted drugs for prostate cancer and to use the retrieval and analysis of the literature library to summarize the adverse effects of different drugs so as to maximize the treatment benefits of targeted therapies.

EVIDENCE ACQUISITION

We performed a systematic literature search of the Medline, EMBASE, PubMed, and Cochrane databases up to March 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Medical Subject Heading (MeSH) terms and keywords such as (prostate cancer) AND (molecular target drugs) AND (side effect) were used. No language restrictions were set on the search process, and all these results were processed independently by two authors. Consensus was reached through discussion once met with any disagreements. The primary endpoint was differential features between different molecular targeted drugs. Secondary endpoints were side effects of different drugs on the body and corresponding prognostic values.

EVIDENCE SYNTHESIS

The Cochrane Collaboration risk of bias tool was used to assess the study quality in terms of sequence generation, allocation concealment, blinding, the completeness of outcome data, selective reporting and other biases. We retrieved 332 articles, of which 49 met the criteria for inclusion. Included studies show that prostatic tumor cells, tumor neovascularization and immune checkpoints are the main means for targeted therapy. Common drugs include 177 Lu-PSMA, Olaparib, Rucaparib, Bevacizumab, Pazopanib, Sorafenib, Cabozantinib, Aflibercept, Ipilimumab, Atezolizumab, Avelumab, Durvalumab. A series of publicly available data suitable for further analysis of side effects. An over-representation analysis of these datasets revealed reasonable dosage and usage is the key to controlling the side effects of targeted drugs. Important information such as the publication year, the first author, location and outcome observation of adverse effects was extracted from the original article. If the study data has some insufficient data, contacting the corresponding authors is necessary. All the studies included prospective nonrandomized and randomized research. Retrospective reviews were also screened according to the relevant to the purpose of this study. Meeting abstracts as well as letters to the editor and editorials were excluded.

STATISTICAL ANALYSIS

Data analysis was based on Cochrane's risk of bias tools to obtain the quality assessment. The included randomized studies used RoB2 and non-randomized ones corresponded to ROBINS-I. Standardized mean differences (SMD) were used to determine relative risk (RR) and side effects between groups. The eggers' test was used to check the publication bias from variable information in the included studies. All p < 0.05 were considered to be significant, and 95% was set as the confidence interval.

CONCLUSIONS

With the approval of a variety of targeted drugs, targeted therapy will be widely used in the treatment of advanced or metastatic prostate cancer. Despite the existence of adverse reactions related to targeted drug treatment, it is still meaningful to adjust the drug dosage or treatment cycle to reduce the occurrence of adverse reactions, improving the treatment benefits of patients.

Combination with vorinostat enhances the antitumor activity of cisplatin in castration-resistant prostate cancer by inhibiting DNA damage repair pathway and detoxification of GSH

BACKGROUND

Like DNA methylation, histone modifications are considered important processes for epigenetic alterations in gene function, and abnormally high expression of histone deacetylases (HDACs) plays a key role in many human diseases. In addition to regulating the acetylation levels of histone and non-histone proteins and gene transcription, HDAC inhibitors as antitumor drugs can also affect the DNA damage repair (DDR) pathway in tumor cells. Prostate cancer (PCa) is one of the most heritable malignancies in which DDR pathway defects can be detected in a considerable proportion of cases. Such defects are more prevalent in castration-resistant prostate cancer (CRPC) and are highly enriched in metastatic lesions. There is currently evidence that DDR pathway-deficient PCa is associated with high-risk biological behaviors and response sensitivity to platinum-based chemotherapy. Platinum-based drugs have been used in multiple clinical trials as monotherapy or in combination with other chemotherapeutic agents for the treatment of CRPC.

METHODS

This study evaluated the combined anticancer effect of (cisplatin) CDDP and the HDAC inhibitors vorinostat (SAHA) on three androgen-dependent cell lines PC-3, DU-145, and C4-2B in vitro. The efficacy and safety of SAHA combined with CDDP in the treatment of CRPC were further verified through animal experiments.

RESULTS

The combination of the two drugs increases cytotoxic effects by increasing DNA damage. Our results showed that the SAHA could not only reduce the expression of homologous recombinant repair proteins BRCA2, BRCA1, PARP1, and RAD51, but also decrease enzymes that Reduce the key enzymes of GSH biosynthesis, GSS and GCLC, and GSTP1 which can catalyze the binding of GSH to cisplatin. The intracellular GSH level also decreased with the increase of SAHA concentration, at the same time, the content of intracellular Pt element.

CONCLUSION

The combination of CDDP and SAHA can produce synergistic anticancer effects in androgen-independent PCa cells in vitro and in vivo. Our results open up a new avenue for the effective treatment of CRPC. To optimize the chemotherapy regimen for patients with advanced PCa, it is necessary to further study the molecular mechanism of platinum drugs, HDAC inhibitors, and their combined action.

Outcomes and prognostic predictors of Lu-177 PSMA radioligand therapy in metastatic castration-resistant prostate cancer (Asian Population Study)

AIM

Lutetium-177 (Lu-177) prostate-specific membrane antigen radioligand therapy (PSMA-RLT) is a promising therapy for metastatic castration-resistant prostate cancer (mCRPC), but there is limited data of its efficacy and safety in Asian population. We aim to explore the clinical outcomes of Lu-177 PSMA-RLT in this population.

METHODS

We evaluated 84 patients with progressive mCRPC receiving Lu-177 PSMA-RLT between 9 May 2018 and 21 February 2022. Lu-177-PSMA-I&T was administered at 6-8-week intervals. Primary end point was overall survival (OS), and secondary end points included prostate-specific antigen (PSA) progression-free survival (PFS), PSA response rate, clinical response, toxicity assessment, and prognostic indicators.

RESULTS

The median OS and PSA PFS were 12.2 and 5.2 months, respectively. PSA decline of ≥50% was observed in 51.8% of patients. Patients achieving PSA response had longer median OS (15.0 vs. 9.5 months, p = .03) and PSA PFS (6.5 vs. 2.9 months, p < .001). Pain score improvement was seen in 19 out of 34 patients. A hematotoxicity of ≥grade 3 was observed in 13 out of 78 patients. Multivariable analyses showed that PSA velocity, alkaline phosphatase, hemoglobin (Hb), and the number of treatment cycles were independent prognostic indicators for OS. The retrospective design was the main limitation of the study.

CONCLUSIONS

Our study demonstrated a similar safety and efficacy of Lu-177 PSMA-RLT in Asian mCRPC patients compared to the existing literature. A PSA decline ≥50% was associated with longer OS and PSA PFS. Several prognostic indicators for patient outcomes were also identified.

A phase I prospective, non-randomized trial of autologous dendritic cell-based cryoimmunotherapy in patients with metastatic castration-resistant prostate cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an immunologically cold disease with dismal outcomes. Cryoablation destroys cancer tissue, releases tumor-associated antigens and creates a pro-inflammatory microenvironment, while dendritic cells (DCs) activate immune responses through processing of antigens. Immunotherapy combinations could enhance the anti-tumor efficacy. This open-label, single-arm, single-center phase I trial determined the safety and tolerability of combining cryoablation and autologous immature DC, without and with checkpoint inhibitors. Immune responses and clinical outcomes were evaluated. Patients with mCRPC, confirmed metastases and intact prostate gland were included. The first participants underwent prostate cryoablation with intratumoral injection of autologous DCs in a 3 + 3 design. In the second part, patients received cryoablation, the highest acceptable DC dose, and checkpoint inhibition with either ipilimumab or pembrolizumab. Sequentially collected information on adverse events, quality of life, blood values and images were analyzed by standard descriptive statistics. Neither dose-limiting toxicities nor adverse events > grade 3 were observed in the 18 participants. Results indicate antitumor activity through altered T cell receptor repertoires, and 33% durable (> 46 weeks) clinical benefit with median 40.7 months overall survival. Post-treatment pain and fatigue were associated with circulating tumor cell (CTC) presence at inclusion, while CTC responses correlated with clinical outcomes. This trial demonstrates that cryoimmunotherapy in mCRPC is safe and well tolerated, also for the highest DC dose (2.0 × 10⁸) combined with checkpoint inhibitors. Further studies focusing on the biologic indications of antitumor activity and immune system activation could be considered through a phase II trial focusing on treatment responses and immunologic biomarkers.