Meta-Analysis Evaluating the Impact of Site of Metastasis on Overall Survival in Men With Castration-Resistant Prostate Cancer

Prognostic value of [18F]FDG PET/CT in metastatic hormone-sensitive prostate cancer at initial diagnosis: a retrospective cohort study

INTRODUCTION

This retrospective study aimed to evaluate the prognostic value of [18F]FDG parameters in patients with visceral and bone metastatic hormone-sensitive prostate cancer (mHSPC).

PATIENTS AND METHODS

This analysis included the mHSPC patients who underwent [18F]FDG PET/CT at the initial diagnosis. Baseline characteristics were analyzed, and the uptake of [18F]FDG was quantified using SUVmax. Kaplan-Meier and Cox proportional hazard regression analysis were employed to evaluate the correlation between SUVmax and patient survival.

RESULTS

Among the 267 patients enrolled, 90 (33.7%) presented with visceral metastases and 177 (66.3%) had bone metastases. The median follow-up for the visceral metastasis group was 35.5 months (IQR 26-53.8 months). The median overall survival for patients with lung, liver, or both metastases were 30, 21 and 17 months, respectively. Patients exhibiting higher [18F]FDG uptake in metastatic lesions experienced shorter overall survival (OS) in comparison to those with lower [18F]FDG uptake, both in the visceral metastases group (17 vs. 31 months, p = 0.002) and the bone metastases group (27.5 vs. 34.5 months, p < 0.001). Cox regression analysis further revealed that increased [18F]FDG uptake in metastatic lesions emerged as a significant risk factor in both OS and progression-free survival (PFS). In contrast, the variability in [18F]FDG uptake in primary lesions did not provide a reliable indicator for predicting prognosis.

CONCLUSIONS

In mHSPC patients, higher [18F]FDG uptake in metastatic lesions indicates shorter survival and increased risk of disease progression. The [18F]FDG SUVmax in primary tumors did not show significant prognostic value. Our study underscores the unique prognostic potential of [18F]FDG PET/CT in mHSPC patients, highlighting its importance in the management of both bone and visceral metastases.

Prognostic role of prostate specific antigen kinetics in primary high volume metastatic hormonal sensitive prostate cancer treated with novel hormonal therapy agents

The prognostic value of prostate-specific antigen (PSA) kinetics in primary high-volume metastatic hormone-sensitive prostate cancer (mHSPC) patients treated with novel hormonal therapy agents is still unclear. Here, we retrospectively reviewed the data of 102 patients with primary high-volume mHSPC who received novel hormonal therapy agents. The median follow-up was 32.25 ± 14.51 months and the median nadir PSA (nPSA) was 0.20 (0.06, 11.71) ng/mL after treatment. The mean time to nPSA was 10.82 ± 7.27 months and 55 patients (53.9%) had a PSA-density (PSA-D) ≤ 0.08 at 3-months. Univariate and multivariate Cox regression analyses showed that the absence of visceral metastases, nPSA ≤ 0.2 and PSA-D ≤ 0.08 were independent prognostic factors for better PFS and OS (all P < 0.05). Moreover, patients with nPSA ≤ 0.2 and PSA-D ≤ 0.08 had the best PFS and OS, and the combination of the nPSA and PSA-D had a better predictive accuracy for PFS and OS than nPSA and PSA-D alone. Thus, Visceral metastases, nPSA and PSA-D were independent prognostic factors for primary high-volume mHSPC patients treated with novel hormonal therapy agents. Patients with lower nPSA and PSA-D had a best survival outcome, and the combination of nPSA and PSA-D had a better effect on prognosis predicting.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Dissecting the Significance of Acid Phosphatase 1 Gene Alterations in Prostate Cancer

PURPOSE

The acid phosphatase 1 (ACP1) gene encodes low-molecular-weight protein tyrosine phosphatase, which is overexpressed in prostate cancer (PC) and a potential therapeutic target. We analyzed ACP1 expression in primary/metastatic PC and its association with molecular profiles and clinical outcomes.

METHODS

NextGen sequencing of DNA (592-gene/whole-exome sequencing)/RNA(whole-transcriptome sequencing) was performed for 5,028 specimens. ACP1-High/ACP1-Low expression was defined as quartile (Q4/1) of RNA transcripts per million (TPM). DNA mutational profiles were analyzed for ACP1-quartile-stratified samples. Gene set enrichment analysis was used for Hallmark collection of pathways. PD-L1+(≥2+, ≥5%; SP142) was tested by immunohistochemistry. Tumor microenvironment's (TME) immune cell fractions were estimated by RNA deconvolution/quanTIseq. Overall survival (OS) was assessed from initial diagnosis/treatment initiation to death/last follow-up.

RESULTS

We included 3,058 (60.8%) samples from the prostate, 634 (12.6%) from lymph node metastases (LNMs), and 1,307 (26.0%) from distant metastases (DMs). ACP1 expression was higher in LNM/DM than prostate (49.8/47.9 v 44.1 TPM; P < .0001). TP53 mutations were enriched in ACP1-Q4 (37.9%[Q4] v 27.0%[Q1]; P < .001) among prostate samples. Pathways associated with cell cycle regulation and oxidative phosphorylation were enriched in ACP1-Q4, whereas epithelial-mesenchymal transition and tumor necrosis factor-alpha signaling via nuclear factor kappa-light-chain-enhancer of activated B-cell pathways were enriched in ACP1-Q1. Neuroendocrine and androgen receptor signaling was increased in ACP1-Q4. M2 macrophages and natural killer cell fractions were increased, whereas T cells and M1 macrophages were decreased in ACP1-Q4. While OS differences between ACP1-Q1/Q4 were not statistically significant, there was a trend for worse OS among ACP1-Q4 prostate samples (Q4 v Q1: hazard ratio [HR], 1.19 [95% CI, 0.99 to 1.42]; P = .06) and DM (HR, 1.12 [95% CI, 0.93 to 1.36]; P = .22) but not LNM (HR, 0.98 [95% CI, 0.74 to 1.29]; P = .87).

CONCLUSION

ACP1-High tumors exhibit a distinct molecular profile and cold TME, highlighting ACP1's potential role in PC pathogenesis and novel therapeutic targeting.

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

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

Sclerotic prostate cancer bone metastasis: woven bone lesions with a twist

Bone metastases are the most severe and prevalent consequences of prostate cancer (PC), affecting more than 80% of patients with advanced PC. PCBMs generate pain, pathological fractures, and paralysis. As modern therapies increase survival, more patients are suffering from these catastrophic consequences. Radiographically, PCBMs are predominantly osteosclerotic, but the mechanisms of abnormal bone formation and how this pathological increase in bone density is related to fractures are unclear. In this study, we conducted a comprehensive analysis on a cohort of 76 cadaveric PCBM specimens and 12 cancer-free specimens as controls. We used micro-computed tomography to determine 3D organization and quantify bone characteristics, quantitative backscattering electron microscopy to characterize mineral content and details in bone structure, nanoindentation to determine mechanical properties, and histological and immunohistochemical analysis of bone structure and composition. We define 4 PCBM phenotypes: osteolytic, mixed lytic-sclerotic, and 2 subgroups of osteosclerotic lesions-those with residual trabeculae, and others without residual trabeculae. The osteosclerotic lesions are characterized by the presence of abnormal bone accumulated on trabeculae surfaces and within intertrabecular spaces. This abnormal bone is characterized by higher lacunae density, abnormal lacunae morphology, and irregular lacunae orientation. However, mineral content, hardness, and elastic modulus at micron-scale were indistinguishable between this irregular bone and residual trabeculae. The collagen matrix of this abnormal bone presents with irregular organization and a prominent collagen III composition. These characteristics suggest that osteosclerotic PCBMs initiate new bone deposition as woven bone; however, the lack of subsequent bone remodeling, absence of lamellar bone deposition on its surface, and presence of collagen III distinguish this pathologic matrix from conventional woven bone. Although the mineralized matrix retains normal bone hardness and stiffness properties, the lack of fibril anisotropy presents a compromised trabecular structure, which may have clinical implications.

Pretherapeutic PSMA PET-Derived Semiquantitative Parameters as Predictors of PSA Response in Patients with mCRPC Receiving [ 177 Lu]Lu-PSMA-617 Radioligand Therapy

Objective  [ 177 Lu]Lu-prostate-specific membrane antigen (PSMA)-617 radioligand therapy (RLT) shows promise for metastatic castration-resistant prostate cancer (mCRPC) patients with positive PSMA positron emission tomography (PET) imaging. Identifying high-risk patients is crucial. We evaluated pretherapeutic PSMA PET-derived parameters to predict prostate-specific antigen (PSA) response in patients undergoing [ 177 Lu]Lu-PSMA-617 RLT. Materials and Methods  We conducted a retrospective analysis among 27 patients (mean age: 71.0 ± 9.5 years; range: 52-85 years) who underwent PSMA PET/computed tomography (CT) and subsequent [ 177 Lu]Lu-PSMA-617 RLT between March 2019 and January 2023. After excluding patients with liver metastases, the number of patients left for analysis was 21 (14 responders and 7 nonresponders). Tumors were semiautomatically delineated with calculation of total tumor volume (PSMA-TV), lesion uptake (PSMA-TLU = PSMA-TV * standardized uptake value [SUV]mean), and lesion quotient (PSMA-TLQ = PSMA-TV/SUVmean) for each patient. Semiquantitative parameters were analyzed only in patients with mCRPC and no liver metastasis. Results  In total, 17/27 patients (62.96%) had a decline in PSA levels; 15/27 patients (55.56%) experienced a decline of > 50%. Pretherapeutic PSMA PET/CT results revealed significant differences in PSMA-TV ( p  = 0.003), PSMA-TLU ( p  = 0.013), and PSMA-TLQ ( p  = 0.011) between responders and nonresponders. SUVmax was significantly correlated to the best percentage change in PSA response after 177 Lu-PSMA-617 treatment ( r  = -0.79, p  = 0.006). No association was observed between PSMA-TV ( p  = 0.367), PSMA-TLU ( p  = 0.128), and PSMA-TLQ ( p  = 0.556), with the best percentage change in PSA response after 177 Lu-PSMA-617 therapy. Conclusion  Pretherapeutic PSMA PET-derived PSMA-TV, PSMA-TLU, and PSMA-TLQ were significant negative predictors of PSA response in patients with mCRPC and no liver metastasis receiving [ 177 Lu]Lu-PSMA-617 RLT.

A single-center retrospective review of metastatic prostate cancer on PSMA position emission tomography/computed tomography: Beyond lymph nodes and bones

BACKGROUND

Prostate-specific membrane antigen (PSMA) Positron emission tomography/computed tomography (PET/CT) has become a crucial imaging modality for the staging of patients with prostate cancer. The purpose of this study is to retrospectively determine the frequency, anatomical distribution, and clinical-pathologic correlates of extra-nodal and extra-osseous metastatic prostate cancer detected on PSMA PET/CT.

METHODS

All available 650 PSMA PET/CT performed in patients with biopsy-proved prostate cancer in our institution between September 2021 and December 2023 were reviewed for the presence of extra-nodal and extra-osseous metastatic disease (M1C disease). Thirty-four patients with M1C disease were identified.

RESULTS

The most frequent sites of visceral/soft tissue metastases were the lungs (58.8%), liver (23.5%) and adrenal glands (20.6%). 75% of patients with lung metastases detected on PSMA PET/CT had concurrent intrathoracic lymph node involvement. A higher frequency of patients with M1C disease (55.9%) had a high Gleason score. The median prostate-specific antigen (PSA) level at the time of the PSMA scan was 20.16 ng/mL. There was a statistically significant association between PSA level and osseous disease (p = 0.004), as well as PSA level and nodal disease (p = 0.008). While a large number of patients had concurrent osseous and nodal disease (82.4% and 79.4%, respectively), no visceral/soft tissue sites demonstrated a significant association with the presence of osseous or nodal involvement.

CONCLUSIONS

Given the increasing utilization of PSMA PET/CT, increased knowledge of the location and pattern of distribution of visceral/soft tissue metastatic sites is crucial not only for staging but also to better understand patterns of therapeutic response. We identified the lungs, liver and adrenal glands as the most common visceral/soft tissue metastatic sites from prostate cancer. We found that higher PSA levels at the time of PSMA PET/CT imaging were positively associated with concurrent osseous and nodal involvement.

Impact of different visceral metastatic sites on survival in metastatic prostate cancer patients

INTRODUCTION

Visceral metastasis is an important predictor for poor outcomes in prostate cancer, however, the prognostic significance surrounding the specific sites of visceral metastasis remains unclear. The aim of this study was to evaluate the impact of different visceral metastatic sites on survival in patients with prostate cancer.

METHODS

We identified patients with metastatic prostate cancer between January 1, 2010 and December 31, 2023 using the TriNetX database. Patients were divided into 4 cohorts according to their specific metastatic sites: lung metastases, brain metastases, liver metastases, and bone metastases. Survival analysis was calculated using the Kaplan-Meier method and Cox regression models.

RESULTS

In total, 59,875 patients diagnosed with metastatic prostate cancer were identified, with 39,495 (65.2%) having bone metastases, 7,573 (12.5%) lung metastases, 5,240 (8.7%) brain metastases, and 7,567 (12.5%) liver metastases. The median overall survival was 44.4 months for patients with bone metastases, 31.9 months for lung metastases, 9.6 months for brain metastases, and 10 months for liver metastases. Lung metastases were associated with an improved survival when compared with liver and brain metastases. For patients with two visceral metastatic sites or concomitant bone metastases, liver metastases were related to worse outcomes. Asian patients experienced better OS than Caucasian and African American patients in visceral metastatic prostate cancer.

CONCLUSION

Patients with lung metastases experienced better survival outcomes in prostate cancer with only one visceral metastatic site. Liver metastases were associated with worse outcomes when there were two visceral metastatic sites combined or concomitant bone metastases. Asian patients displayed improved survival rates when compared with both Caucasian and African American patients in visceral metastatic prostate cancer.

Prostate cancer-induced endothelial-cell-to-osteoblast transition drives immunosuppression in the bone-tumor microenvironment through Wnt pathway-induced M2 macrophage polarization

Immune checkpoint therapy has limited efficacy for patients with bone-metastatic castration-resistant prostate cancer (bmCRPC). To improve immunotherapy for bmCRPC, we aimed to identify the mechanism of bmCRPC-induced changes in the immune microenvironment. Among bmCRPC patients, higher levels of a 32-gene M2-like macrophage signature in bone metastasis samples correlated with shorter overall survival. Immunohistochemistry showed that CD206-positive (CD206+) macrophages were enriched in bmCRPC bone biopsy specimens compared with primary tumors or lymph node metastases. In preclinical osteogenic prostate cancer (Pca) xenograft models, CD206+ macrophages were recruited to areas with tumor-induced bone. RNA sequencing (RNAseq) analysis showed higher expression of an M2-like gene signature, with activated canonical and noncanonical Wnt pathways, in tumor-associated macrophages isolated from osteogenic tumors (bone-TAMs) than in TAMs isolated from nonosteogenic tumors (ctrl-TAMs). Mechanistic studies showed that endothelial cells (ECs) that had undergone EC-to-osteoblast (EC-to-OSB) transition, the precursors of tumor-induced OSBs, produced paracrine factors, including Wnts, CXCL14, and lysyl oxidase, which induced M2 polarization and recruited M2-like TAMs to the bone-tumor microenvironment (bone-TME). Bone-TAMs suppressed CD8+ T cells' proliferation and cytolytic activity, and these effects were partially reversed by treating bone-TAMs with Wnt inhibitors. Genetic or pharmacological inhibition of Pca-induced EC-to-OSB transition reduced the levels of M2-like macrophages in osteogenic tumors. Our study demonstrates that Pca-induced EC-to-OSB transition drives immunosuppression in the bone-TME, suggesting that therapies that reduce Pca-induced bone formation may improve immunotherapeutic outcomes for bmCRPC.

Survival Patterns Based on First-site-specific Visceral Metastatic Prostate Cancer: Are Outcomes of Visceral Metastases the Same?

Background and objective

Visceral metastatic disease in prostate cancer patients conveys a poor prognosis. Using advanced imaging techniques, studies have demonstrated increasing detection rates of visceral metastasis. Visceral metastases are now seen in up to 30-60% of prostate cancer patients. Survival patterns of site-specific visceral metastasis are described poorly in the literature. Here, we sought to investigate survival patterns in prostate cancer patients according to their first detected site of visceral metastasis.

Methods

Retrospectively, we identified 203 prostate cancer patients with visceral metastases from the Mayo Clinic Advanced Prostate Cancer Registry. Patients were divided into three groups according to the first site of visceral metastases detected: lung, brain, or liver. Visceral metastases were detected primarily on either metabolic imaging (C-11 choline) or prostate-specific membrane antigen positron emission tomography computed tomography (CT) scan. Confirmation of visceral metastasis diagnosis was established with either biopsy when feasible or focused conventional imaging, including focused CT or magnetic resonance imaging. Overall survival and cancer-specific survival were estimated using the Kaplan-Meier method. Univariate and multivariate Cox regression model was conducted to assess different variables that affect overall and cancer-specific survival.

Key findings and limitations

Over a median (interquartile range) follow-up duration of 16.2 (3.9-49.8) mo, the overall and cancer-specific survival of the entire cohort suggests better survival patterns in patients with first-site lung metastases than in patients with first-site brain or liver metastases (p < 0.0001). In univariate and multivariate analyses of factors impacting patients' overall and cancer-specific survival, a high prostate-specific antigen level at diagnosis of visceral metastasis, concomitant bone and lymph node disease, and more than four visceral metastases were associated with poor overall and cancer-specific survival (p < 0.05). On the contrary, first-site lung metastasis was associated with improved overall and cancer-specific survival, compared with first-site liver and brain metastases (p < 0.001).

Conclusions and clinical implications

These data suggest that prostate cancer patients with visceral metastatic disease have varying survival patterns according to first-site detected visceral metastasis. In our cohort, patients with first-site lung metastasis demonstrated better survival outcomes than patients with first-site brain or liver metastasis.

Patient summary

Our study explored the survival outcomes among patients with visceral metastatic prostate cancer employing cutting-edge imaging methods. Prostate cancer patients with metastases to different organs have different survival rates. Patients with cancer spreading to the lungs first showed better survival than those with cancer spreading to the brain or liver first.

Heterogeneity of Radiological Progression Patterns and Association with Outcomes in Patients with Metastatic Prostate Cancer

BACKGROUND

With an increasing number of clinical trials using radiographic progression-free survival (rPFS) instead of overall survival as the primary study endpoint, the heterogeneity of different radiological progression patterns in rPFS and postprogression survival (PPS) remains unclear.

OBJECTIVE

Herein, we investigate the proportion of various radiological progression patterns in patients with metastatic hormone-sensitive prostate cancer (mHSPC) and metastatic castration-resistant prostate cancer (mCRPC), and further explore the differences in rPFS and PPS between patients exhibiting single- or multicategory progression patterns.

DESIGN, SETTING, AND PARTICIPANTS

This post hoc, retrospective secondary analysis was based on individual patient data from LATITUDE (phase 3 randomized mHSPC study) and COU-AA-302 (phase 3 randomized mCRPC study). Patients with complete imaging follow-up data and radiological progression were included in the analysis.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The rPFS and PPS in LATITUDE and COU-AA-302 were evaluated. The proportion of patients exhibiting each progression pattern was calculated, and a survival analysis was conducted using the Kaplan-Meier method.

RESULTS AND LIMITATIONS

Of the 489 mHSPC patients studied, 366 experienced single-category progression, while the remaining 123 patients (25.2%) exhibited simultaneous occurrence of different progressive events (multicategory radiological progression). Of the 534 mCRPC patients studied, 390 experienced single-category progression, while the remaining 144 patients (27.0%) experienced multicategory progressive events. Among mCRPC patients, the rPFS of bone progression was the shortest. In contrast, among mHSPC patients, the rPFS of target lesion enlargement is the shortest, followed by bone progression. Notably, patients experiencing a single-category progression pattern displayed comparable rPFS to but significantly longer PPS than those experiencing multicategory progression patterns (PPS mHSPC cohort: 21.5 vs 6.9 mo, p < 0.0001; mCRPC cohort: 23.6 vs 15.7 mo, p < 0.0001). The study is limited by its hypothesis-generating nature. Therefore, the observed phenomena in our research necessitate validation through future prospective studies.

CONCLUSIONS

Patients who experience multicategory radiological progression represent a significant proportion, accounting for approximately 25% of all men with mHSPC or mCRPC. Patients with multicategory radiological progression patterns had similar rPFS to but significantly shorter PPS than those experiencing single-category progression patterns. In future clinical trials and clinical practice, radiological progression patterns should be recognized as a crucial determinant of prognosis, while also serving as the stratification or inclusion criteria for second-line treatment clinical trials.

PATIENT SUMMARY

In this study, we observed that among men with metastatic prostate cancer, those who experienced two or more radiological events during a single visit had a worse prognosis than those who experienced isolated radiological events.

Cancer-associated fibroblasts and prostate cancer stem cells: crosstalk mechanisms and implications for disease progression

The functional heterogeneity and ecological niche of prostate cancer stem cells (PCSCs), which are major drivers of prostate cancer development and treatment resistance, have attracted considerable research attention. Cancer-associated fibroblasts (CAFs), which are crucial components of the tumor microenvironment (TME), substantially affect PCSC stemness. Additionally, CAFs promote PCSC growth and survival by releasing signaling molecules and modifying the surrounding environment. Conversely, PCSCs may affect the characteristics and behavior of CAFs by producing various molecules. This crosstalk mechanism is potentially crucial for prostate cancer progression and the development of treatment resistance. Using organoids to model the TME enables an in-depth study of CAF-PCSC interactions, providing a valuable preclinical tool to accurately evaluate potential target genes and design novel treatment strategies for prostate cancer. The objective of this review is to discuss the current research on the multilevel and multitarget regulatory mechanisms underlying CAF-PCSC interactions and crosstalk, aiming to inform therapeutic approaches that address challenges in prostate cancer treatment.

Clinical implications of Wnt pathway genetic alterations in men with advanced prostate cancer

BACKGROUND

Aberrant Wnt signaling has been implicated in prostate cancer tumorigenesis and metastasis in preclinical models but the impact of genetic alterations in Wnt signaling genes in men with advanced prostate cancer is unknown.

METHODS

We utilized the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) clinical-genomic database for this retrospective analysis. Patients with activating mutations in CTNNB1 or RSPO2 or inactivating mutations in APC, RNF43, or ZNRF3 were defined as Wnt-altered, while those lacking such alterations were defined as Wnt non-altered. We compared patient characteristics and clinical outcomes as well as co-occurring genetic alterations according to Wnt alteration status.

RESULTS

Of the 1498 patients included, 193 (12.9%) were Wnt-altered. These men had a statistically significant 2-fold increased prevalence of liver and lung metastases as compared with Wnt non-altered patients at the time of initial diagnosis, (4.66% v 2.15% ; 6.22% v 3.07%), first metastatic disease diagnosis (10.88% v 5.29%; 13.99% v 6.21%), and CRPC development (11.40% v 6.36%; 12.95% v 5.29%). Wnt alterations were associated with more co-occurring alterations in RB1 (10.4% v 6.2%), AR (38.9% vs 25.7%), SPOP (13.5% vs 4.1%), FOXA1 (6.7% vs 2.8%), and PIK3CA (10.9% vs 5.1%). We found no significant differences in overall survival or other clinical outcomes from initial diagnosis, first metastatic disease, diagnosis of CRPC, or with AR inhibition for mCRPC between the Wnt groups.

CONCLUSIONS

Wnt-altered patients with prostate cancer have a higher prevalence of visceral metastases and are enriched in RB1, AR, SPOP, FOXA1, and PIK3CA alterations. Despite these associations, Wnt alterations were not associated with worse survival or treatment outcomes in men with advanced prostate cancer.

Multiparametric Whole-Body MRI: A Game Changer in Metastatic Prostate Cancer

Prostate cancer ranks among the most prevalent tumours globally. While early detection reduces the likelihood of metastasis, managing advanced cases poses challenges in diagnosis and treatment. Current international guidelines support the concurrent use of 99Tc-Bone Scintigraphy and Contrast-Enhanced Chest and Abdomen CT for the staging of metastatic disease and response assessment. However, emerging evidence underscores the superiority of next-generation imaging techniques including PSMA-PET/CT and whole-body MRI (WB-MRI). This review explores the relevant scientific literature on the role of WB-MRI in metastatic prostate cancer. This multiparametric imaging technique, combining the high anatomical resolution of standard MRI sequences with functional sequences such as diffusion-weighted imaging (DWI) and bone marrow relative fat fraction (rFF%) has proved effective in comprehensive patient assessment, evaluating local disease, most of the nodal involvement, bone metastases and their complications, and detecting the increasing visceral metastases in prostate cancer. It does have the advantage of avoiding the injection of contrast medium/radionuclide administration, spares the patient the exposure to ionizing radiation, and lacks the confounder of FLARE described with nuclear medicine techniques. Up-to-date literature regarding the diagnostic capabilities of WB-MRI, though still limited compared to PSMA-PET/CT, strongly supports its widespread incorporation into standard clinical practice, alongside the latest nuclear medicine techniques.

Prostate-specific Membrane Antigen: Interpretation Criteria, Standardized Reporting, and the Use of Machine Learning

Prostate-specific membrane antigen targeting positron emission tomography (PSMA-PET) is routinely used for the staging and restaging of patients with various stages of prostate cancer. For clear communication with referring physicians and to improve inter-reader agreement, the use of standardized reporting templates is mandatory. Increasingly, tumor volume is used by reporting and response assessment frameworks to prognosticate patient outcome or measure response to therapy. However, the quantification of tumor volume is often too time-consuming in routine clinical practice. Machine learning-based tools can facilitate the quantification of tumor volume for improved outcome prognostication.

Distinct CT imaging features of new liver metastases from primary genitourinary cancers

PURPOSE

To apply natural language processing (NLP) to a large volume of structured radiology reports in the investigation of CT imaging features of new liver metastases from primary genitourinary cancers.

METHODS

In this retrospective study, a previously reported NLP model was applied to consecutive structured CT reports from 2016 to 2022 to predict those patients with primary genitourinary cancer who developed liver metastasis. Pathology or imaging follow-up served as the reference standard for validating NLP predictions. Subsequently, diagnostic CTs of the identified patients were qualitatively assessed by two radiologists, whereby several imaging features of new liver metastasis were assessed. Proportions of the assessed imaging features were compared between primary genitourinary cancers using the Chi-square or Fisher's exact test.

RESULTS

In 112 patients (mean age = 72 years; 83 males), the majority of new liver metastases were hypovascular (73.2%), well defined (76.6%), homogenous (66.9%), and without necrotic/cystic component (73.2%). There was a higher proportion of iso- to hyperdense liver metastases for primary kidney cancer vs other primary genitourinary cancers (42.5% in kidney cancer; 2.3% in ureter/bladder cancer, 8% in prostate cancer, and 0% in testicular cancer; p < 0.05) and a higher proportion of new liver metastases with ill-defined margin for primary prostate cancer vs other primary genitourinary cancers (44.0% in prostate cancer, 15.0% in kidney cancer, 18.6% in ureter/bladder cancer, and 25.0% in testicular cancer; p < 0.05).

CONCLUSION

New liver metastases from primary genitourinary cancers tend to be hypovascular and show several distinct imaging features between different primary genitourinary cancers.

Exploring membranous NECTIN-4 expression patterns and enfortumab vedotin response in prostate cancer

Antibody-drug conjugates (ADCs) represent a novel type of targeted cancer therapy combining the specificity of monoclonal antibodies with the cytotoxicity of conventional chemotherapy. Recently, ADCs have demonstrated practice-changing efficacy across diverse solid cancers. The anti-NECTIN-4 ADC enfortumab vedotin (EV) has just been approved for patients with urothelial cancer and is currently under investigation for patients with castration-resistant prostate cancer (CRPC e.g. Phase II ENCORE trial). Our objective was to evaluate the efficacy of EV in established prostate cancer (PCa) cell lines and to examine the membranous NECTIN-4 expression in primary tumours (PRIM) and distant metastases (MET). NECTIN-4 was heterogeneously expressed in the panel of PCa cell lines. EV led to growth inhibition in NECTIN-4 expressing PCa cells (22Rv1 and LNCaP), whereas the NECTIN-4-negative PC-3 cells were significantly less responsive to EV, emphasizing the dependence of EV response on its target expression. Immunohistochemical staining revealed moderate membranous NECTIN-4 expression only in a small subgroup of CRPC patients with lung and peritoneal MET [n = 3/22 with H-score ≥100, median H-score 140 (IQR 130-150)], while 100% of PRIM (n = 48/48) and 86.4% of common MET sites (n = 19/22), including lymph node, bone and liver MET, were NECTIN-4 negative. In summary, EV may be effective in NECTIN-4-positive PCa. However, our findings demonstrate that the tumoural NECTIN-4 expression is predominantly low in metastatic PCa, which suggests that EV may only be effective in a biomarker-stratified subgroup.

The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study

BACKGROUND

COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes.

METHODS

Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2, hospitalized and received supplemental O2, admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality.

RESULTS

Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity.

CONCLUSIONS

Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

PSMA-PET follow-up to assess response in patients not receiving PSMA therapy: Is there value beyond localization of disease?

Introduction: Prostate Specific Membrane Antigen Positron Emission Tomography (PSMA-PET) is routinely used for the staging of patients with prostate cancer, but data on response assessment are sparse and primarily stem from metastatic castration-resistant prostate cancer (mCRPC) patients treated with PSMA radioligand therapy. Still, follow-up PSMA-PET is employed in earlier disease stages in case of clinical suspicion of disease persistence, recurrence or progression to decide if localized or systemic treatment is indicated. Therefore, the prognostic value of PSMA-PET derived tumor volumes in earlier disease stages (i.e., hormone-sensitive prostate cancer (HSPC) and non-[177Lu]Lu-PSMA-617 (LuPSMA) therapy castration resistant prostate cancer (CRPC)) are evaluated in this manuscript. Methods: A total number of 73 patients (6 primary staging, 42 HSPC, 25 CRPC) underwent two (i.e., baseline and follow-up, median interval: 379 days) whole-body [68Ga]Ga-PSMA-11 PET/CT scans between Nov 2014 and Dec 2018. Analysis was restricted to non-LuPSMA therapy patients. PSMA-PETs were retrospectively analyzed and primary tumor, lymph node-, visceral-, and bone metastases were segmented. Body weight-adjusted organ-specific and total tumor volumes (PSMAvol: sum of PET volumes of all lesions) were measured for baseline and follow-up. PSMAvol response was calculated as the absolute difference of whole-body tumor volumes. High metastatic burden (>5 metastases), RECIP 1.0 and PSMA-PET Progression Criteria (PPP) were determined. Survival data were sourced from the cancer registry. Results: The average number of tumor lesions per patient on the initial PET examination was 10.3 (SD 28.4). At baseline, PSMAvol was strongly associated with OS (HR 3.92, p <0.001; n = 73). Likewise, response in PSMAvol was significantly associated with OS (HR 10.48, p < 0.005; n = 73). PPP achieved significance as well (HR 2.19, p <0.05, n = 73). Patients with hormone sensitive disease and poor PSMAvol response (upper quartile of PSMAvol change) in follow-up had shorter outcome (p < 0.05; n = 42). PSMAvol in bones was the most relevant parameter for OS prognostication at baseline and for response assessment (HR 31.11 p < 0.001; HR 32.27, p < 0.001; n = 73). Conclusion: PPP and response in PSMAvol were significantly associated with OS in the present heterogeneous cohort. Bone tumor volume was the relevant miTNM region for OS prognostication. Future prospective evaluation of the performance of organ specific PSMAvol in more homogeneous cohorts seems warranted.

IL-23 inhibitor enhances the effects of PTEN DNA-loaded lipid nanoparticles for metastatic CRPC therapy

Introduction: Metastatic castration-resistant prostate cancer (mCRPC) patients face challenges due to limited treatment options. About 50% of patients with mCRPC have a functional loss of phosphatase and tensin homology deleted on chromosome 10 (PTEN), leading to tumor progression, metastasis, and immune suppression. Moreover, elevated IL-23 produced by myeloid-derived suppressor cells (MDSCs) is found in CRPC patients, driving tumor progression. Therefore, a combination strategy based on PTEN restoration and IL-23 inhibition may block CRPC progression and metastasis. Methods: The antitumor effect of restoring PTEN expression combined with the IL-23 inhibitor Apilimod was studied in a mouse model of bone metastasis CRPC and mouse prostate cancer RM-1 cells. To verify the targeting ability of PTEN DNA coated with lipid nanoparticles (LNP@PTEN) in vitro and in vivo. In addition, RT-qPCR and flow cytometry were used to investigate the related mechanisms of the antitumor effect of LNP@PTEN combined with Apilimod. Results: LNPs exhibited significant tumor-targeting and tumor accumulation capabilities both in vitro and in vivo, enhancing PTEN expression and therapeutic efficacy. Additionally, the combination of LNP@PTEN with the IL-23 inhibitor Apilimod demonstrated enhanced inhibition of tumor growth, invasion, and metastasis (particularly secondary organ metastasis) compared to other groups, and extended the survival of mice to 41 days, providing a degree of bone protection. These effects may be attributed to the PTEN function restoration combined with IL-23 inhibition, which help reverse immune suppression in the tumor microenvironment by reducing MDSCs recruitment and increasing the CD8+/CD4+ T cell ratio. Discussion: In summary, these findings highlight the potential of LNPs for delivering gene therapeutic agents. And the combination of LNP@PTEN with Apilimod could achieve anti-tumor effects and improve tumor microenvironment. This combinational strategy opens new avenues for the treatment of mCRPC.

Tumour-based Mutational Profiles Predict Visceral Metastasis Outcome and Early Death in Prostate Cancer Patients

BACKGROUND

Visceral metastases are known to occur in advanced prostate cancer, usually when the tumour is resistant to androgen deprivation and, have worse outcomes regardless of therapies.

OBJECTIVE

To analyse genomic alterations in tumour samples according to their lymphatic, bone, and visceral metastatic stages and overall survival.

DESIGN, SETTING, AND PARTICIPANTS

We selected 200 patients with metastatic prostate cancer. Genomic profiling of 111 genes and molecular signatures (homologous recombination deficiency [HRD], microsatellite instability, and tumour burden mutation) was performed with the MyChoice test (Myriad Genetics, Inc, Salt Lake City, UT, USA).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The association between genomic profiles and visceral metastatic evolution was evaluated using logistic regression. Kaplan-Meier and Cox proportional hazard analyses were used for analyses of early death.

RESULTS AND LIMITATIONS

A total of 173 (87%) genomic profiles were obtained. Eighty-four (49%) patients died during the follow-up period (median duration = 76 mo). TP53 was the most frequently mutated gene, followed by FANC genes, including BRCA2, and those of the Wnt-pathway (APC/CTNNB1). TP53 gene mutations were more frequent in patients of European (42%) than in those of African (16%) ancestry. An HRD score of >25 was predictive of FANC gene mutations. The mutational status of TP53 (p < 0.001) and APC (p = 0.002) genes were significantly associated with the risk of visceral metastases. The mutational status of CTNNB1 (p = 0.001), TP53 (p = 0.015), BRCA2 (p = 0.027), and FANC (p = 0.005) genes were significantly associated with an earlier age at death. The limitations are the retrospective study design based on a selection of genes and the low frequency of certain molecular events.

CONCLUSIONS

Mutations in the TP53 gene and genes (APC/CTNNB1) related to the Wnt pathway are associated with metastatic visceral dissemination and early death. These genomic alterations could be considered as markers to identify prostate cancer patients at a high risk of life-threatening disease who might benefit from more intensified treatment or new targeted therapies.

PATIENT SUMMARY

In this report, we evaluated the relationships between genomic profiles (gene mutations and molecular signatures) of tumour samples from patients with metastatic prostate cancer and early death. We found that mutations of specific genes, notably TP53 and APC/CTNNB1 related to the Wnt pathway, are associated with visceral metastatic progression and an earlier age at death.

Comparative analysis of prognosis and gene expression in prostate cancer patients with site-specific visceral metastases

INTRODUCTION

Prostate cancer patients with visceral metastases often exhibited poor prognoses. Few researches had compared the prognostic impact and gene expression profiles among distinct visceral metastatic sites. Therefore, we conducted a comprehensive study utilizing data from the Surveillance, Epidemiology, and End Results (SEER) database and the Gene Expression Omnibus database.

PATIENTS AND METHODS

We analyzed the prostate cancer-specific mortality (PCSM) risk for 8,170 patients diagnosed with metastatic prostate cancer (mPCa) between 2000 and 2019, utilizing data from the SEER 17 registry database. Patients with metastatic disease in nonregional lymph nodes, bones, brains, livers, and lungs were identified. Competing risks regression was employed to evaluate the effect of visceral metastatic disease sites on PCSM. Differentially expressed genes (DEGs) between visceral metastases were assessed using data from the GSE6752 dataset. A relative protein-protein interaction (PPI) network was constructed based on STRING analysis. Furthermore, we explored the distribution of DEGs in various normal tissues and tumor tissues using the Human Protein Atlas and GEPIA.

RESULTS

Competing risks regression analysis revealed that liver and lung metastases had a substantial impact on PCSM (hazard ratio 2.24, 95% confidence interval 1.70-2.95, P < 0.001; hazard ratio 1.30, 95% confidence interval 1.06-1.59, P = 0.012, respectively). Seven significant DEGs were identified from samples of liver and lung metastases (HERV-FRD, NUDT12, FAM63A, SCGB3A1, CEACAM6, LOC440416, SFTPB) and were associated with respiratory gaseous exchange, pulmonary surfactant metabolism, and fibronectin matrix formation in PPI network analysis. Notably, the expression levels of the three DEGs significantly upregulated in lung metastases were also found to be higher in normal lung tissues compared to normal liver tissues.

CONCLUSION

Patients diagnosed with mPCa and presenting with liver and/or lung metastases exhibit poorer prognoses. SCGB3A1, identified as a tumor suppressor gene, may contribute to the better survival prognosis observed in patients with prostate cancer lung metastases compared to those with liver metastases. The gene expression profiles in these two specific metastatic sites reveal a combination of both heterogeneity and homogeneity.

A Phase I Study of Acapatamab, a Half-life Extended, PSMA-Targeting Bispecific T-cell Engager for Metastatic Castration-Resistant Prostate Cancer

PURPOSE

Safety and efficacy of acapatamab, a prostate-specific membrane antigen (PSMA) x CD3 bispecific T-cell engager were evaluated in a first-in-human study in metastatic castration-resistant prostate cancer (mCRPC).

PATIENTS AND METHODS

Patients with mCRPC refractory to androgen receptor pathway inhibitor therapy and taxane-based chemotherapy received target acapatamab doses ranging from 0.003 to 0.9 mg in dose exploration (seven dose levels) and 0.3 mg (recommended phase II dose) in dose expansion intravenously every 2 weeks. Safety (primary objective), pharmacokinetics, and antitumor activity (secondary objectives) were assessed.

RESULTS

In all, 133 patients (dose exploration, n = 77; dose expansion, n = 56) received acapatamab. Cytokine release syndrome (CRS) was the most common treatment-emergent adverse event seen in 97.4% and 98.2% of patients in dose exploration and dose expansion, respectively; grade ≥ 3 was seen in 23.4% and 16.1%, respectively. Most CRS events were seen in treatment cycle 1; incidence and severity decreased at/beyond cycle 2. In dose expansion, confirmed prostate-specific antigen (PSA) responses (PSA50) were seen in 30.4% of patients and radiographic partial responses in 7.4% (Response Evaluation Criteria in Solid Tumors 1.1). Median PSA progression-free survival (PFS) was 3.3 months [95% confidence interval (CI): 3.0-4.9], radiographic PFS per Prostate Cancer Clinical Trials Working Group 3 was 3.7 months (95% CI: 2.0-5.4). Acapatamab induced T-cell activation and increased cytokine production several-fold within 24 hours of initiation. Treatment-emergent antidrug antibodies were detected in 55% and impacted serum exposures in 36% of patients in dose expansion.

CONCLUSIONS

Acapatamab was safe and tolerated and had a manageable CRS profile. Preliminary signs of efficacy with limited durable antitumor activity were observed. Acapatamab demonstrated pharmacokinetic and pharmacodynamic activity.

Overall Survival of Metastatic Prostate Cancer Patients According to Location of Visceral Metastatic Sites

INTRODUCTION

It is unknown whether specific locations of visceral metastatic sites affect overall survival (OS) of metastatic prostate cancer (mPCa) patients. We tested the association between specific locations of visceral metastatic sites and OS in mPCa patients.

MATERIALS AND METHODS

Within Surveillance, Epidemiology and End Results database (2010-2016), survival analyses relied on specific locations of visceral metastases: lung only vs. liver only vs. brain only vs. ≥2 visceral sites. Kaplan-Meier plots and Cox regression models were fitted.

RESULTS

Of 1827 patients, 1044 (57%) harbored lung only visceral metastases vs. 457 (25%) liver only vs. 131 (7%) brain only vs. 195 (11%) ≥2 visceral sites. Median OS was 22 months in all patients vs. 33 months in lung only vs. 15 months in liver only vs. 16 months in brain only vs. 15 months in patients with ≥2 visceral sites. Highest OS was recorded in lung only visceral metastases patients, especially when concomitant nonvisceral metastases were located in lymph nodes only (median OS 57 months) vs. bone only (26 months) vs. lymph nodes and bone (28 months). Liver only, brain only or ≥2 visceral sites exhibited poor OS, regardless of concomitant nonvisceral metastases type (median OS from 13 to 19 months).

CONCLUSION

In mPCa patients, lung only visceral metastases, especially when associated with lymph node only nonvisceral metastases, portend the best prognosis. Conversely, visceral metastatic sites other than lung portend poor prognosis, regardless of concomitant nonvisceral metastases type.

Prediction of plasma ctDNA fraction and prognostic implications of liquid biopsy in advanced prostate cancer

No consensus strategies exist for prognosticating metastatic castration-resistant prostate cancer (mCRPC). Circulating tumor DNA fraction (ctDNA%) is increasingly reported by commercial and laboratory tests but its utility for risk stratification is unclear. Here, we intersect ctDNA%, treatment outcomes, and clinical characteristics across 738 plasma samples from 491 male mCRPC patients from two randomized multicentre phase II trials and a prospective province-wide blood biobanking program. ctDNA% correlates with serum and radiographic metrics of disease burden and is highest in patients with liver metastases. ctDNA% strongly predicts overall survival, progression-free survival, and treatment response independent of therapeutic context and outperformed established prognostic clinical factors. Recognizing that ctDNA-based biomarker genotyping is limited by low ctDNA% in some patients, we leverage the relationship between clinical prognostic factors and ctDNA% to develop a clinically-interpretable machine-learning tool that predicts whether a patient has sufficient ctDNA% for informative ctDNA genotyping (available online: https://www.ctDNA.org ). Our results affirm ctDNA% as an actionable tool for patient risk stratification and provide a practical framework for optimized biomarker testing.

UCHL1 is a potential molecular indicator and therapeutic target for neuroendocrine carcinomas

Neuroendocrine carcinomas, such as neuroendocrine prostate cancer and small-cell lung cancer, commonly have a poor prognosis and limited therapeutic options. We report that ubiquitin carboxy-terminal hydrolase L1 (UCHL1), a deubiquitinating enzyme, is elevated in tissues and plasma from patients with neuroendocrine carcinomas. Loss of UCHL1 decreases tumor growth and inhibits metastasis of these malignancies. UCHL1 maintains neuroendocrine differentiation and promotes cancer progression by regulating nucleoporin, POM121, and p53. UCHL1 binds, deubiquitinates, and stabilizes POM121 to regulate POM121-associated nuclear transport of E2F1 and c-MYC. Treatment with the UCHL1 inhibitor LDN-57444 slows tumor growth and metastasis across neuroendocrine carcinomas. The combination of UCHL1 inhibitors with cisplatin, the standard of care used for neuroendocrine carcinomas, significantly delays tumor growth in pre-clinical settings. Our study reveals mechanisms of UCHL1 function in regulating the progression of neuroendocrine carcinomas and identifies UCHL1 as a therapeutic target and potential molecular indicator for diagnosing and monitoring treatment responses in these malignancies.

The Detection and Negative Reversion of Circulating Tumor Cells as Prognostic Biomarkers for Metastatic Castration-Resistant Prostate Cancer with Bone Metastases Treated by Enzalutamide

Enzalutamide is a second-generation androgen receptor inhibitor that increases overall survival (OS) rates in patients with metastatic castration-resistant prostate cancer (mCRPC). This study evaluates the efficacy of circulating tumor cell (CTC) status as a prognostic biomarker following enzalutamide administration. A retrospective subgroup analysis and prognostic survey were conducted on 43 patients with mCRPC and bone metastases treated in Juntendo University-affiliated hospitals from 2015 to 2022. Patients were treated with 160 mg enzalutamide daily. CTC analyses on blood samples were performed regularly before and every three months after treatment. The relationship between the patients' clinical factors and the OS rate was analyzed using the log-rank test; the median OS was 37 months. Patients with no detected CTCs at baseline showed significantly longer OS than those with detectable CTCs at baseline. Furthermore, patients demonstrating negative reversion of CTCs during enzalutamide treatment had significantly longer OS than patients with CTC-positivity. Two biomarkers-higher hemoglobin at baseline and achieving negative reversion of CTCs-were significantly associated with prolonged OS. This study suggests that patients achieving CTC-negative reversion during treatment for mCRPC with bone metastases exhibit improved long-term OS. Chronological measurement of CTC status might be clinically useful in the treatment of mCRPC.

A real-world experience of pembrolizumab monotherapy in microsatellite instability-high and/or tumor mutation burden-high metastatic castration-resistant prostate cancer: outcome analysis

BACKGROUND

The efficacy of pembrolizumab monotherapy in metastatic castration-resistant prostate cancer patients (mCRPC) when stratified by MSI-H and/or TMB-H is poorly defined. Additionally, outcomes based on sequencing source (i.e., tissue or liquid biopsy) have not been well described. We sought to assess outcomes of pembrolizumab monotherapy in patients with mCRPC and compare efficacy based on MSI-H and/or TMB-H when identified by tissue or liquid biopsy.

METHODS

A retrospective analysis was performed of mCRPC patients treated at Mayo Clinic with pembrolizumab monotherapy between 2018 and 2023. Objective response rates (ORR), median progression-free survival (mPFS), and overall survival (mOS), were determined by RECIST v1.1 criteria.

RESULTS

Twenty-two patients with mCRPC received pembrolizumab monotherapy for at least 3 cycles for a MSI-H or TMB-H indication. All patients had next generation sequencing (NGS) performed via tissue (n = 11) or liquid (n = 10) biopsy source. The ORR was 50% (27.3% complete response and 22.7% had partial response). The mPFS for TMB 10-14.9 mut/Mb (n = 4), TMB 15-24.9 mut/Mb (n = 6), and TMB ≥ 25 mut/Mb (n = 10) was 2.1, not reached (NR), and NR, respectively (p = 0.0003). The mOS for these same groups was 5.1 months, 20.5 months, and not reached, respectively. Among patients with TMB-H without co-occurring MSI-H or CDK12 (n = 6), none experienced a response and only one patient had stable disease compared to patients with MSI-H (n = 12) for whom the ORR was 75%. Immunotherapy responsive alterations such as ATRX and PTCH1 mutations were frequently noticed among patients who had complete response (CR).

CONCLUSIONS

Our hypothesis-generating study suggests that MSI-H drives the efficacy of pembrolizumab in mCRPC with better survival outcomes as TMB increases. Clinicians should consider alternative treatment strategies for advanced prostate cancer when TMB-H is present without co-occurring MSI-H or CDK12.

Comprehensive prognostic prediction of metastatic breast cancer treated with eribulin using blood‑based parameters and ratio

Eribulin is widely used to treat metastatic breast cancer (BC). Higher neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are associated with higher mortality in several cancer types. However, the association between BC prognosis and peripheral immune status remains controversial. In the present study, the relative effects of NLR and PLR on survival in patients with metastatic BC were quantified and their clinical prognostic value was evaluated. This retrospective study included 156 patients with metastatic BC who received eribulin monotherapy at Saitama Medical University International Medical Center. Clinicopathological features were examined (peripheral blood findings and biochemical liver and kidney function test results) and univariate and multivariate analyses were conducted of the overall survival (OS). The 156 patients treated with eribulin had a median follow-up duration of 18.3 months. Before eribulin treatment, patients with absolute lymphocyte counts (ALC) >1,500/µl, NLR <3.0, and PLR <150 had significantly longer OS than those with lower ALC, and higher NLR and PLR (median OS, 25.5 vs. 15.5 months; P<0.01; 20.3 vs. 13.6 months, P<0.01; and 29.2 vs. 14.8 months; P<0.001, respectively). Patients with anemia [hemoglobin (Hb) <10 g/dl] or liver dysfunction [albumin-bilirubin (ALBI) grade 2/3] had significantly shorter OS than those without (P<0.001, respectively). Multivariate analysis revealed low ALBI grade (P<0.001), high Hb (P<0.01) and low PLR (P<0.05) as independent factors of longer OS after eribulin administration. Low PLR, anemia and liver dysfunction might be factors associated with prolonged OS in patients with metastatic BC on eribulin therapy, which could be clinically useful, as their evaluation requires neither new equipment nor invasive testing.

Prostate Cancer Liver Metastasis: An Ominous Metastatic Site in Need of Distinct Management Strategies

Prostate cancer liver metastasis (PCLM), seen in upwards of 25% of metastatic castration-resistant PC (mCRPC) patients, is the most lethal site of mCRPC with a median overall survival of 10-14 months. Despite its ominous prognosis and anticipated rise in incidence due to longer survival with contemporary therapy, PCLM is understudied. This review aims to summarize the existing literature regarding the risk factors associated with the development of PCLM, and to identify areas warranting further research. A literature search was conducted through Ovid MEDLINE from 2000 to March 2023. Relevant subject headings and text words were used to capture the following concepts: "Prostatic Neoplasms", "Liver Neoplasms", and "Neoplasm Metastasis". Citation searching identified additional manuscripts. Forty-one studies were retained for detailed analysis. The clinical risk factors for visceral/liver metastasis included <70 years, ≥T3 tumor, N1 nodal stage, de novo metastasis, PSA >20 ng/mL, and a Gleason score >8. Additional risk factors comprised elevated serum AST, LDH or ALP, decreased Hb, genetic markers like RB1 and PTEN loss, PIK3CB and MYC amplification, as well as numerous PC treatments either acting directly or indirectly through inducing liver injury. Further research regarding predictive factors, early detection strategies, and targeted therapies for PCLM are critical for improving patient outcomes.

GALNT12 suppresses the bone-specific prostate cancer metastasis by activating BMP pathway via the O-glycosylation of BMPR1A

Bone metastasis caused the majority death of prostate cancer (PCa) but the mechanism remains poorly understood. In this present study, we show that polypeptide N-acetylgalactosaminyltransferase 12 (GALNT12) suppresses bone-specific metastasis of PCa. GALNT12 suppresses proliferation, migration, invasion and cell division ability of PCa cells by activating the BMP pathway. Mechanistic investigations showed that GALNT12 augments the O-glycosylation of BMPR1A then actives the BMP pathway. Activated BMP signaling inhibits the expression of integrin αVβ3 to reduce the bone-specific seeding of PCa cells. Furthermore, activated BMP signaling remolds the immune microenvironment by suppressing the STAT3 pathway. Our results of this study illustrate the role and mechanism of GALNT12 in the process of bone metastasis of PCa and identify GALNT12 as a potential therapeutic target for metastatic PCa.

A phase II study evaluating the efficacy of enzalutamide and the role of liquid biopsy for evaluation of ARv7 in mCRPC patients with measurable metastases including visceral disease (Excalibur study)

Background

Up to 30% of patients with metastatic castration-resistant prostate cancer (mCRPC) develop visceral metastases, which are associated with a poor prognosis.

Objectives

Efficacy of enzalutamide in mCRPC patients with measurable metastases, including visceral and/or extra-regional lymph nodes.

Methods

In this phase II multicenter study, patients with mCRPC and measurable metastases received enzalutamide as the first line. Primary endpoint: 3-month (mo) disease control rate (DCR) defined as the proportion of patients with complete (CR) or partial response (PR) or stable disease (SD) as per Response Evaluation Criteria in Solid Tumors 1.1. Secondary endpoint: safety. Exploratory endpoint: the association between ARv7 splicing variants in basal circulating tumor cell (CTC)-enriched blood samples and treatment response/resistance using the AdnaTest ProstateCancerSelect kit and the AdnaTest ProstateCancer Panel AR-V7.

Results

From March 2017 to January 2021, 68 patients were enrolled. One patient never started treatment. Median age: 72 years. A total of 52 patients (78%) received enzalutamide as a first line for mCRPC. The median follow-up was 32 months. At the 3-month assessment, 24 patients presented an SD, 1 patient achieved a CR, and 23 patients had a PR (3-mo-DCR of 72%). Discontinuations due to adverse events (AEs), disease-related death, or disease progression occurred in 9%, 6%, and 48% of patients. All patients reported at least one grade (G) 1-2 AE: the most common were fatigue (49%) and hypertension (33%). Six G3 AEs were reported: two hypertension, one seizure, one fatigue, one diarrhea, and one headache. Basal detection of ARv7 was significantly associated with poor treatment response (p = 0.034) and a nonsignificant association (p = 0.15) was observed between ARv7 detection and response assessments. At month 3, ARv7 was detected in 57%, 25%, and 15% of patients undergoing progressive disease, SD, and PR, respectively.

Conclusion

The study met its primary endpoint, showing the efficacy of enzalutamide in men with mCRPC and measurable metastatic lesions in visceral and/or lymph node sites.

Trial registration

ClinicalTrials.gov Identifier: NCT03103724. First Posted: 6 April 2017. First patient enrollment: 19 April 2017.

Standardized PSMA-PET Imaging of Advanced Prostate Cancer

Imaging of advanced prostate cancer is a challenging task, as it requires longitudinal characterization of disease extent in a standardized way to enable appropriate treatment selection and evaluation of treatment efficacy. In the last years, prostate-specific membrane antigen (PSMA)-PET/CT has become the reference standard examination for patients with advanced prostate cancer. Together with the rise of PSMA-PET, standardized frameworks for the reporting of image findings have been proposed, eg, the Prostate Cancer Molecular Imaging Standardized Evaluation (PROMISE) and the structured reporting system for PSMA targeted PET imaging (PSMA-RADS) framework. Therefore, recent evidence on PSMA-PET derived tumor volume as useful a biomarker for outcome prognostication and related frameworks will be discussed in the article. The PROMISE framework recommends quantifying the tumor volume per-organ system, which accounts for the fact that the location of the metastases greatly influence its biological aggressiveness. In addition, changes in PSMA-PET derived tumor volume have been shown to be promising biomarkers for response assessment. Limitations of PSMA-PET will also be discussed because the tumor volume might not always be suited for response assessment. As a pitfall of PSMA-based systems, decreasing PSMA-expression might erroneously be interpreted as response to therapy. Also, especially for patients with limited disease, the tumor volume might not be ideal for response assessment. Therefore, various frameworks have been introduced to objectively measure response to therapy with PSMA-PET. Amongst these, the PSMA-PET progression (PPP) criteria and the response evaluation criteria in PSMA (RECIP) are optimized for earlier and later phenotypes of advanced prostate cancer, respectively. Variables needed to determine PPP or RECIP outcome on PSMA-PET are recorded under the umbrella of PROMISE recommendations. In this article, various reporting and response assessment frameworks are explained and discussed. Also, recent evidence for the relevance of PSMA-PET biomarkers for clinical management and outcome prognostication are shown.

Predictive significance of inflammatory markers and mGPS in metastatic castration-resistant prostate cancer treated with abiraterone or enzalutamide

BACKGROUND

Prostate cancer is a prevalent cancer in men worldwide, and castration-resistant prostate cancer (CRPC) is characterized by disease progression despite androgen deprivation therapy. While clinical and prognostic biomarkers have been identified in CRPC, the significance of serum inflammatory markers remains unclear.

MATERIALS AND METHODS

This retrospective study included 79 CRPC patients treated with abiraterone or enzalutamide. Inflammatory markers, including the modified Glasgow prognostic score (mGPS), systemic immune-inflammation index (SII), and neutrophil-to-lymphocyte ratio (NLR), were assessed as predictive tools for treatment response. Patient data were obtained from medical charts, and statistical analyses were performed.

RESULTS

The median age of the patients was 67 years, with most having a Gleason score of 8-10. The median values for NLR, PLR, and SII were 2.9, 168.5, and 713.5, respectively. The objective response rate (ORR) to abiraterone or enzalutamide therapy was 55.1%. mGPS showed a significant association with ORR, with the mGPS 0 group having the highest response rate (59.5%). Median progression-free survival (PFS) was 12.8 months, and median overall survival (OS) was 35.4 months. Palliative radiotherapy during therapy and PSA doubling time were independent prognostic factors for PFS.

CONCLUSIONS

mGPS and PSA doubling time significantly impacted survival, and mGPS significantly predicted the treatment response in mCRPC, which may lead to further prospective studies.

Newly developed preclinical models reveal broad-spectrum CDK inhibitors as potent drugs for CRPC exhibiting primary resistance to enzalutamide

Androgen-deprivation therapy is a standard treatment for advanced prostate cancer. However, most patients eventually acquire resistance and progress to castration-resistant prostate cancer (CRPC). In this study, we established new CRPC cell lines, AILNCaP14 and AILNCaP15, from LNCaP cells under androgen-deprived conditions. Unlike most pre-existing CRPC cell lines, both cell lines expressed higher levels of androgen receptor (AR) and prostate-specific antigen (PSA) than parental LNCaP cells. Moreover, these cells exhibited primary resistance to enzalutamide. Since AR signaling plays a significant role in the development of CRPC, PSA promoter sequences fused with GFP were introduced into AILNCaP14 cells to conduct GFP fluorescence-based chemical screening. We identified flavopiridol, a broad-spectrum CDK inhibitor, as a candidate drug that could repress AR transactivation of CRPC cells, presumably through the inhibition of phosphorylation of AR on the serine 81 residue (pARSer81 ). Importantly, this broad-spectrum CDK inhibitor inhibited the proliferation of AILNCaP14 cells both in vitro and in vivo. Moreover, a newly developed liver metastatic model using AILNCaP15 cells revealed that the compound attenuated tumor growth of CRPC harboring highly metastatic properties. Finally, we developed a patient-derived xenograft (PDX) model of CRPC and DCaP CR from a patient presenting therapeutic resistance to enzalutamide, abiraterone, and docetaxel. Flavopiridol successfully suppressed the tumor growth of CRPC in this PDX model. Since ARSer81 was found to be phosphorylated in clinical CRPC samples, our data suggested that broad-spectrum CDK inhibitors might be a potent candidate drug for the treatment of CRPC, including those exhibiting primary resistance to enzalutamide.

Prostate cancer-induced endothelial-to-osteoblast transition generates an immunosuppressive bone tumor microenvironment

Immune checkpoint therapy has limited efficacy for patients with bone metastatic castrate-resistant prostate cancer (bmCRPC). In this study, we revealed a novel mechanism that may account for the relative resistance of bmCRPC to immune checkpoint therapy. We found that prostate cancer (PCa)-induced bone via endothelial-to-osteoblast (EC-to-OSB) transition causes an ingress of M2-like macrophages, leading to an immunosuppressive bone tumor microenvironment (bone-TME). Analysis of a bmCRPC RNA-seq dataset revealed shorter overall survival in patients with an M2-high versus M2-low signature. Immunohistochemical (IHC) analysis showed CD206 + M2-like macrophages were enriched in bmCRPC specimens compared with primary tumors or lymph node metastasis. In osteogenic PCa xenografts, CD206 + macrophages were enriched adjacent to tumor-induced bone. FACS analysis showed an increase in CD206 + cells in osteogenic tumors compared to non-osteogenic tumors. Genetic or pharmacological inhibition of the EC-to-OSB transition reduced aberrant bone and M2-like macrophages in osteogenic tumors. RNAseq analysis of tumor-associated macrophages from osteogenic (bone-TAMs) versus non-osteogenic (ctrl-TAMs) tumors showed high expression of an M2-like gene signature, canonical and non-canonical Wnt pathways, and a decrease in an M1-like gene signature. Isolated bone-TAMs suppressed T-cell proliferation while ctrl-TAMs did not. Mechanistically, EC-OSB hybrid cells produced paracrine factors, including Wnts, CXCL14 and LOX, which induced M2 polarization and recruited M2-like TAMs to bone-TME. Our study thus links the unique EC-to-OSB transition as an "upstream" event that drives "downstream" immunosuppression in the bone-TME. These studies suggest that therapeutic strategies that inhibit PCa-induced EC-to-OSB transition may reverse immunosuppression to promote immunotherapeutic outcomes in bmCRPC.

Significance

The insight that prostate cancer-induced bone generates an immunosuppressive bone tumor microenvironment offers a strategy to improve responses to immunotherapy approaches in patients with bone metastatic castrate-resistant prostate cancer.

Liver Metastases and Immune Checkpoint Inhibitor Efficacy in Patients With Refractory Metastatic Colorectal Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

Immune checkpoint inhibitors (ICIs) have limited activity in microsatellite-stable (MSS) or mismatch repair-proficient (pMMR) colorectal cancer. Recent findings suggest the efficacy of ICIs may be modulated by the presence of liver metastases (LM).

Objective

To investigate the association between the presence of LM and ICI activity in advanced MSS colorectal cancer.

Design, Setting, and Participants

In this secondary analysis of the Canadian Cancer Trials Group CO26 (CCTG CO.26) randomized clinical trial, patients with treatment-refractory colorectal cancer were randomized in a 2:1 fashion to durvalumab plus tremelimumab or best supportive care alone between August 10, 2016, and June 15, 2017. The primary end point was overall survival (OS) with 80% power and 2-sided α = .10. The median follow-up was 15.2 (0.2-22.0) months. In this post hoc analysis performed from February 11 to 14, 2022, subgroups were defined based on the presence or absence of LM and study treatments.

Intervention

Durvalumab plus tremelimumab or best supportive care.

Main Outcomes and Measures

Hazard ratios (HRs) and 90% CIs were calculated based on a stratified Cox proportional hazards regression model. Plasma tumor mutation burden at study entry was determined using a circulating tumor DNA assay. The primary end point of the study was OS, defined as the time from randomization to death due to any cause; secondary end points included progression-free survival (PFS) and disease control rate (DCR).

Results

Of 180 patients enrolled (median age, 65 [IQR, 36-87] years; 121 [67.2%] men; 19 [10.6%] Asian, 151 [83.9%] White, and 10 [5.6%] other race or ethnicity), LM were present in 127 (70.6%). For patients with LM, there was a higher proportion of male patients (94 of 127 [74.0%] vs 27 of 53 [50.9%]; P = .005), and the time from initial cancer diagnosis to study entry was shorter (median, 40 [range, 8-153] vs 56 [range, 14-181] months; P = .001). Plasma tumor mutation burden was significantly higher in patients with LM. Patients without LM had significantly improved PFS with durvalumab plus tremelimumab (HR, 0.54 [90% CI, 0.35-0.96]; P = .08; P = .02 for interaction). Disease control rate was 49% (90% CI, 36%-62%) in patients without LM treated with durvalumab plus tremelimumab, compared with 14% (90% CI, 6%-38%) in those with LM (odds ratio, 5.70 [90% CI, 1.46-22.25]; P = .03). On multivariable analysis, patients without LM had significantly improved OS and PFS compared with patients with LM.

Conclusions and Relevance

In this secondary analysis of the CCTG CO.26 study, the presence of LM was associated with worse outcomes for patients with advanced colorectal cancer. Patients without LM had improved PFS and higher DCR with durvalumab plus tremelimumab. Liver metastases may be associated with poor outcomes of ICI treatment in advanced colorectal cancer and should be considered in the design and interpretation of future clinical studies evaluating this therapy.

Oligometastatic Prostate Cancer Treated with Stereotactic Body Radiation Therapy: The Role of Three-Dimensional Tumour Volume in Patient Survival

AIMS

The definition of oligometastatic prostate cancer (OPCa) is currently based solely on the maximum number of detectable metastases, as there are no validated biomarkers available. The aim of this study was to identify novel predictive factors for OPCa patients who underwent metastases-directed therapy.

MATERIALS AND METHODS

This monocentre, retrospective study included consecutive OPCa patients with a maximum of five metastases in up to two organs, detected with choline- or PSMA-positron emission tomography, who were treated with metastases-directed stereotactic body radiation therapy. Endpoints were overall survival and progression-free survival, assessed with Kaplan-Meier analysis. Univariate and multivariable Cox regression was carried out to evaluate the association between clinical factors and survival outcomes.

RESULTS

Between 2009 and 2021, 163 patients and 320 metastases were treated with 226 stereotactic body radiation therapy courses. The median three-dimensional metastatic tumour volume was 4.1 cm3, with a range from 0.01 to 233.4 cm3. In total, 87 (53.4%), 21 (12.9%) and 55 (33.7%) metastases were classified as cN1, cM1a and cM1b, respectively. The median follow-up was 28.5 months. The rates of overall survival at 1, 3 and 5 years were 89.5% (95% confidence interval 83.4-93.4), 74.9% (95% confidence interval 66.1-81.7) and 57.2% (95% confidence interval 45.8-67.1), respectively. Multivariable analysis showed that overall survival reduced with the increase in three-dimensional total tumour volume (hazard ratio 1.93, 95% confidence interval 1.06-3.52; P = 0.030) and confirmed a significant difference between cN1 versus cM1a-b disease (hazard ratio 1.81, 95% confidence interval 1.01-3.25; P = 0.046). The cut-off value of total volume correlated with the highest risk of death was 20 cm3 (hazard ratio 2.37, 95% confidence interval 1.34-4.18; P = 0.003). The median progression-free survival was 17.8 months, with 1-, 3- and 5-year rates of 63.7% (95% confidence interval 55.4-70.9), 31.5% (95% confidence interval 22.8-40.6) and 24.7% (95% confidence interval 16.0-34.3).

CONCLUSIONS

This study identified three-dimensional total tumour volume and the site of oligometastases as significant predictors of survival in OPCa patients treated with metastases-directed therapy. These parameters can potentially be used to personalised treatment and improve patient outcome.

SIUrO best practice recommendations to optimize BRCA 1/2 gene testing from DNA extracted from bone biopsy in mCRPC patients (BRCA Optimal Bone Biopsy Procedure: BOP)

The main guidelines and recommendations for the implementation of the BRCA1/2 somatic test do not focus on the clinical application of predictive testing on bone metastases, a frequent condition in metastatic prostate cancer, by analyzing the critical issues encountered by laboratory practice. Our goal is to produce a document (protocol) deriving from a multidisciplinary team approach to obtain high quality nucleic acids from biopsy of bone metastases. This document aims to compose an operational check-list of three phases: the pre-analytical phase concerns tumor cellularity, tissue processing, sample preservation (blood/FFPE), fixation and staining, but above all the decalcification process, the most critical phase because of its key role in allowing the extraction of somatic DNA with a good yield and high quality. The analytical phase involves the preparation of the libraries that can be analyzed in various NGS genetic sequencing platforms and with various bioinformatics software for the interpretation of sequence variants. Finally, the post-analytical phase that allows to report the variants of the BRCA1/2 genes in a clear and usable way to the clinician who will use these data to manage cancer therapy with PARP Inhibitors.

ACAA2 is a novel molecular indicator for cancers with neuroendocrine phenotype

BACKGROUND

Neuroendocrine phenotype is commonly associated with therapy resistance and poor prognoses in small-cell neuroendocrine cancers (SCNCs), such as neuroendocrine prostate cancer (NEPC) and small-cell lung cancer (SCLC). Expression levels of current neuroendocrine markers exhibit high case-by-case variability, so multiple markers are used in combination to identify SCNCs. Here, we report that ACAA2 is elevated in SCNCs and is a potential molecular indicator for SCNCs.

METHODS

ACAA2 expressions in tumour xenografts, tissue microarrays (TMAs), and patient tissues from prostate and lung cancers were analysed via immunohistochemistry. ACAA2 mRNA levels in lung and prostate cancer (PC) patients were assessed in published datasets.

RESULTS

ACAA2 protein and mRNA levels were elevated in SCNCs relative to non-SCNCs. Medium/high ACAA2 intensity was observed in 78% of NEPC PDXs samples (N = 27) relative to 33% of adeno-CRPC (N = 86), 2% of localised PC (N = 50), and 0% of benign prostate specimens (N = 101). ACAA2 was also elevated in lung cancer patient tissues with neuroendocrine phenotype. 83% of lung carcinoid tissues (N = 12) and 90% of SCLC tissues (N = 10) exhibited medium/high intensity relative to 40% of lung adenocarcinoma (N = 15).

CONCLUSION

ACAA2 expression is elevated in aggressive SCNCs such as NEPC and SCLC, suggesting it is a potential molecular indicator for SCNCs.

Targeting Liver Metastases to Potentiate Immunotherapy in MS-Stable Colorectal Cancer-A Review of the Literature

Immunotherapy has revolutionized the treatment of several cancers, including melanoma and lung cancer. However, for colorectal cancer, it is ineffective for 95% of patients with microsatellite-stable disease. Recent evidence suggests that the liver's immune microenvironment plays a pivotal role in limiting the effectiveness of immunotherapy. There is also evidence to show that targeting liver metastases with locoregional therapies, such as surgery or irradiation, could potentiate immunotherapy for these patients. This review presents evidence from preclinical studies regarding the underlying mechanisms and from clinical studies that support this approach. Furthermore, we outline potential directions for future clinical trials. This innovative strategy could potentially establish immunotherapy as an effective treatment for MS-stable colorectal cancer patients, which are currently considered resistant.

A new histone deacetylase inhibitor remodels the tumor microenvironment by deletion of polymorphonuclear myeloid-derived suppressor cells and sensitizes prostate cancer to immunotherapy

BACKGROUND

Prostate cancer (PCa) is the most common malignancy diagnosed in men. Immune checkpoint blockade (ICB) alone showed disappointing results in PCa. It is partly due to the formation of immunosuppressive tumor microenvironment (TME) could not be reversed effectively by ICB alone.

METHODS

We used PCa cell lines to evaluate the combined effects of CN133 and anti-PD-1 in the subcutaneous and osseous PCa mice models, as well as the underlying mechanisms.

RESULTS

We found that CN133 could reduce the infiltration of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), and CN133 combination with anti-PD-1 could augment antitumor effects in the subcutaneous PCa of allograft models. However, anti-PD-1 combination with CN133 failed to elicit an anti-tumor response to the bone metastatic PCa mice. Mechanistically, CN133 could inhibit the infiltration of PMN-MDSCs in the TME of soft tissues by downregulation gene expression of PMN-MDSC recruitment but not change the gene expression involved in PMN-MDSC activation in the CN133 and anti-PD-1 co-treatment group relative to the anti-PD-1 alone in the bone metastatic mice model.

CONCLUSIONS

Taken together, our work firstly demonstrated that combination of CN133 with anti-PD-1 therapy may increase the therapeutic efficacy to PCa by reactivation of the positive immune microenvironment in the TME of soft tissue PCa.

What should be the future direction of development in the field of prostate cancer with lung metastasis?

BACKGROUND

Since the start of the 21st century, prostate cancer with lung metastasis (PCLM) has accumulated significant scientific research output. However, a systematic knowledge framework for PCLM is still lacking.

AIM

To reconstruct the global knowledge system in the field of PCLM, sort out hot research directions, and provide reference for the clinical and mechanism research of PCLM.

METHODS

We retrieved 280 high-quality papers from the Web of Science Core Collection and conducted a bibliometric analysis of keywords, publication volume, and citation frequency. Additionally, we selected differentially expressed genes from global high-throughput datasets and performed enrichment analysis and protein-protein interaction analysis to further summarize and explore the mechanisms of PCLM.

RESULTS

PCLM has received extensive attention over the past 22 years, but there is an uneven spatial distribution in PCLM research. In the clinical aspect, the treatment of PCLM is mainly based on chemotherapy and immunotherapy, while diagnosis relies on methods such as prostate-specific membrane antigen positron emission tomography/computed tomography. In the basic research aspect, the focus is on cell adhesion molecules and signal transducer and activator of transcription 3, among others. Traditional treatments, such as chemotherapy, remain the mainstay of PCLM treatment, while novel approaches such as immunotherapy have limited effectiveness in PCLM. This study reveals for the first time that pathways related to coronavirus disease 2019, cytokine-cytokine receptor interaction, and ribosome are closely associated with PCLM.

CONCLUSION

Future research should focus on exploring and enhancing mechanisms such as cytokine-cytokine receptor interaction and ribosome and improve existing mechanisms like cadherin binding and cell adhesion molecules.

Prevalence and prognosis of bone metastases in common solid cancers at initial diagnosis: a population-based study

OBJECTIVE

Bone is one of the most common target sites for advanced tumours. The objective was to survey the prevalence and prognosis of bone metastases in 12 common solid malignant tumours.

DESIGN

A retrospective cohort study.

METHODS

A total of 1 425 332 patients with a primary cancer between 2010 and 2015 were identified using the Surveillance, Epidemiology, and End Results database. We computed the prevalence and prognosis of bone metastases in each cancer and compared their survival in different stages. The Kaplan-Meier method and Cox logistic regression were used to analyse survival and quantify the effect of bone metastases.

RESULTS

This study included 89 782 patients with bone metastases at diagnosis. Lung cancer had the highest prevalence (18.05%), followed by liver cancer (6.63%), nasopharyngeal carcinoma (6.33%) and renal cancer (5.45%). Breast cancer (32.1%), prostate cancer (25.9%), thyroid cancer (46.9%) and nasopharyngeal carcinoma (24.8%) with only bone metastases had a 5-year survival rate of over 20%. Compared with patients at the stage previous to metastasis, bone metastases significantly increased the risk of mortality and decreased survival, especially for those with prostate cancer (adjusted HR: 18.24). Other concomitant extraosseous metastases worsened patient survival. Bone was the most common site of metastasis for prostate cancer, while for colorectal cancer, multiorgan metastases were predominant.

CONCLUSIONS

This study provides the prevalence and prognosis of bone metastases at the initial diagnosis of common solid cancers. In addition, it demonstrates the impact of bone metastases on survival. These results can be used for early screening of metastases, clinical trial design and assessment of prognosis.

Prognosis and Treatment Outcomes of Bone Metastasis in Gallbladder Adenocarcinoma: A SEER-Based Study

BACKGROUND

Gallbladder carcinoma (GBC) is a rare, aggressive malignancy comprising 0.5% of gastrointestinal cancers. It has poor survival outcomes due to its insidious onset, lack of standardized screening, and limited therapies. Advanced-stage diagnosis with liver, lymph node, and peritoneal metastasis is common, while bone metastasis is rare. The knowledge on bone metastasis in GBC is limited to case reports and small series, and its clinical significance is largely unexplored.

METHODS

The study extracted the demographic and clinical variables of patients with metastatic (M1) gallbladder adenocarcinoma from the Surveillance, Epidemiology, and End Results (SEER) database between 2011 and 2020. Descriptive statistics were used to analyze the demographic characteristics. The multivariate Cox regression analysis was used to calculate the hazard ratio. The overall survival (OS) was assessed using the Kaplan-Meier method, and the log-rank test was utilized to compare the survival between the groups.

RESULTS

A total of 2724 patients were included in the study. A total of 69% of the patients were female, and the median age was 68 (range 24-90+). A total of 7.4% of the patients had bone metastasis on diagnosis. The multivariate Cox analysis identified bone metastasis as an independent mortality risk factor in metastatic GBC (HR 1.50, p < 0.001). The patients were divided into two age groups: a younger age group (18-74 years) and an older age group (75+ years). In the younger group, the median OS with and without bone metastasis was 3 and 5 months, respectively (p < 0.0001). In the older age group, there was no significant difference in the OS between the patients with and without bone metastasis (p = 0.35). In the younger group who were treated with chemotherapy, the patients with bone metastasis had a significantly worse OS (median OS 5 months vs. 8 months, p < 0.0001). In the untreated group, the patients with bone metastasis in the younger age group had a significantly worse OS (median OS 1 month vs. 2 months, p = 0.014). In the patients with bone metastasis, those who did not receive chemotherapy had a significantly worse OS than those who were treated with chemotherapy in both age groups (younger age group: median OS 1 month vs. 5 months, p < 0.0001 and older age group: median OS 1 month vs. 5 months, p = 0.041).

CONCLUSIONS

Our findings suggest that the presence of bone metastasis in gallbladder adenocarcinoma is an independent prognostic factor associated with unfavorable survival outcomes in the younger age group (18-74 years). However, in the older age group (75+ years), the presence of bone metastasis did not impact the survival. Treatment with chemotherapy was associated with extended survival in all patients. Thus, early detection and aggressive management of bone metastasis, including the consideration of chemotherapy, may be crucial in improving the OS and quality of life for individuals with gallbladder adenocarcinoma.

Prostate cancer and bone: clinical presentation and molecular mechanisms

Prostate cancer (PCa) is an increasingly prevalent health problem in the developed world. Effective treatment options exist for localized PCa, but metastatic PCa has fewer treatment options and shorter patient survival. PCa and bone health are strongly entwined, as PCa commonly metastasizes to the skeleton. Since androgen receptor signaling drives PCa growth, androgen-deprivation therapy whose sequelae reduce bone strength constitutes the foundation of advanced PCa treatment. The homeostatic process of bone remodeling - produced by concerted actions of bone-building osteoblasts, bone-resorbing osteoclasts, and regulatory osteocytes - may also be subverted by PCa to promote metastatic growth. Mechanisms driving skeletal development and homeostasis, such as regional hypoxia or matrix-embedded growth factors, may be subjugated by bone metastatic PCa. In this way, the biology that sustains bone is integrated into adaptive mechanisms for the growth and survival of PCa in bone. Skeletally metastatic PCa is difficult to investigate due to the entwined nature of bone biology and cancer biology. Herein, we survey PCa from origin, presentation, and clinical treatment to bone composition and structure and molecular mediators of PCa metastasis to bone. Our intent is to quickly yet effectively reduce barriers to team science across multiple disciplines that focuses on PCa and metastatic bone disease. We also introduce concepts of tissue engineering as a novel perspective to model, capture, and study complex cancer-microenvironment interactions.

18 F-sodium fluoride positron emission tomography quantitation of bone metastases in African American and non-African American men with metastatic prostate cancer

BACKGROUND

Bone is the most common site of metastases in men with prostate cancer. The objective of this study was to explore potential racial differences in the distribution of tumor metastases in the axial and appendicular skeleton.

METHODS

We conducted a retrospective review of patients with metastatic prostate cancer to the bone as detected by 18 F-sodium fluoride positron emission tomography/computed tomography (18 F-NaF PET/CT) scans. In addition to describing patients' demographics and clinical characteristics, the metastatic bone lesions, and healthy bone regions were detected and quantified volumetrically using a quantitative imaging platform (TRAQinform IQ, AIQ Solutions).

RESULTS

Forty men met the inclusion criteria with 17 (42%) identifying as African Americans and 23 (58%) identifying as non-African Americans. Most of the patients had axial (skull, ribcage, and spine) disease. The location and the number of lesions in the skeleton of metastatic prostate cancer patients with low disease burden were not different by race.

CONCLUSIONS

In low-disease burden patients with metastatic prostate cancer, there were no overall differences by race in the location and number of lesions in axial or appendicular skeleton. Therefore, given equal access to molecular imaging, African Americans might derive similar benefits. Whether this holds true for patients with a higher disease burden or for other molecular imaging techniques is a topic for further study.

Evaluation of enhanced permeability effect and different linear energy transfer of radionuclides in a prostate cancer xenograft model

We have previously investigated the biodistribution and therapy effect of a humanized monoclonal antibody targeting free prostate-specific antigen (fPSA) intended for theranostics of hormone-refractory prostate cancer. In the present study, we evaluated the off-target effect and different linear energy transfer (LET) radionuclides without the effect of PSA targeting by using an antibody with the same scaffold as previously used immunoconjugates but with random, non-specific, antigen binding region. This allows us to identify alterations generated by specific targeting and those related to passive bystander effects, such as enhanced permeability and retention (EPR). A control humanized IgG monoclonal antibody (hIgG1) and an isotype control IgG monoclonal antibody were conjugated with the chelator CHX-A"-DTPA. The immunoconjugate was radiolabeled with either Lutetium-177 ([177Lu]Lu) or Indium-111 ([111In]In). A biodistribution study in mice carrying LNCaP xenografts, was performed to evaluate the non-specific uptake of [177Lu]Lu-hIgG1 in tumors and normal organs. Further, therapy studies of [177Lu]Lu and [111In]In labeled IgG were performed in BALB/c mice carrying LNCaP xenografts. Tumor tissues of treated xenografts and control were sectioned and immunohistochemically stained for Ki67 and PSA. The highest tumor uptake for the [177Lu]Lu-hIgG1 was seen at 72 hours (7.2±2 %IA/g), when comparing the tumor uptake of the fPSA targeting antibody to the non-specific antibody, the non-specific antibody contributes to half of the tumor uptake at 72 h. The liver uptake was 3.1±0.5 %IA/g at 24 h, 2.8±0.5 %IA/g at 72 h and 1.3±0.6 %IA/g at 120 h in LNCaP xenografts, which was approximately three times lower at 24 h and two times lower at 72 h than for the antibody with preserved targeting. Immunohistochemical labeling showed a reduction of PSA expression and a reduction of Ki67 labeled cells in the [111In]In treated LNCaP tumors, compared to vehicle and [177Lu]Lu treated mice. In conclusion, we found that specific targeting might negatively influence normal organ uptake when targeting secreted antigens. Furthermore, different energy deposition i.e. linear energy transfer of a radionuclide might have diverse effects on receptor expression and cell proliferation in tumors.

Incidence trends and survival of metastatic prostate cancer with bone and visceral involvement: 2010-2019 surveillance, epidemiology, and end results

Background

The incidence of prostate cancer (PCa) has continued to increase since the US Preventive Services Task Force (USPSTF) recommendations against prostate-specific antigen (PSA)-based screening for all men in 2012, approximately half of additional diagnosed cases are advanced-stage, including regional PCa and metastatic PCa (mPCa). It is very important to investigate the shift in mPCa incidence and mPCa-related mortality risk, as the survival of mPCa remains poor.

Objective

To investigate the incidence temporal trend of mPCa stratified by metastatic site, including bone and visceral metastatic involvement, and potential survival improvements.

Materials

Based on the recently released Surveillance, Epidemiology, and End Results (SEER) data (2010-2019), the age-adjusted incidence rates of mPCa with bone and visceral involvement with annual percentage changes (APCs) were assessed by a joinpoint regression model in men aged 45 years and older by age and race groups, and potential recent improvements in overall survival (OS) and cancer-specific survival (CSS) were estimated by the Kaplan-Meier method and Cox regression model.

Results

From 2010 to 2019, a total of 19081 (84.8%) and 3413 (15.2%) mPCa patients with bone and visceral involvement, respectively, were recorded in the SEER database. Considering all races and age groups, the incidence rate of mPCa with bone metastasis remained stable during 2017-2019 (APC, 0.9%; p=0.421) after increasing during 2010-2017 (APC, 5.8%; p<0.001). For visceral metastasis, the incidence rate increased by 12.3% (p<0.001) per year from 2010-2019. Non-Hispanic Black men have higher incidence rates than other populations, and the Non-Hispanic Black to Non-Hispanic White incidence rates ratios of mPCa declined with the greater increasing pace of incidence of Non-Hispanic White men. There was a slight improvement in both OS and CSS among men with bone and visceral metastasis involvement when comparing the 2013-2016 period to the pre-2013 period.

Conclusion

Our findings show that the incidence of mPCa with bone and visceral involvement has increased in recent years and that there has been a potential improvement in survival. Future efforts are still needed to watch closely if the rising incidence trends continue.