Noninvasive Detection of Neuroendocrine Prostate Cancer through Targeted Cell-free DNA Methylation

Castration-resistant prostate cancer (CRPC) is a heterogeneous disease associated with phenotypic subtypes that drive therapy response and outcome differences. Histologic transformation to castration-resistant neuroendocrine prostate cancer (CRPC-NE) is associated with distinct epigenetic alterations, including changes in DNA methylation. The current diagnosis of CRPC-NE is challenging and relies on metastatic biopsy. We developed a targeted DNA methylation assay to detect CRPC-NE using plasma cell-free DNA (cfDNA). The assay quantifies tumor content and provides a phenotype evidence score that captures diverse CRPC phenotypes, leveraging regions to inform transcriptional state. We tested the design in independent clinical cohorts (n = 222 plasma samples) and qualified it achieving an AUC > 0.93 for detecting pathology-confirmed CRPC-NE (n = 136). Methylation-defined cfDNA tumor content was associated with clinical outcomes in two prospective phase II clinical trials geared towards aggressive variant CRPC and CRPC-NE. These data support the application of targeted DNA methylation for CRPC-NE detection and patient stratification.

SIGNIFICANCE

Neuroendocrine prostate cancer is an aggressive subtype of treatment-resistant prostate cancer. Early detection is important, but the diagnosis currently relies on metastatic biopsy. We describe the development and validation of a plasma cell-free DNA targeted methylation panel that can quantify tumor fraction and identify patients with neuroendocrine prostate cancer noninvasively. This article is featured in Selected Articles from This Issue, p. 384.

LSD1 inhibition suppresses ASCL1 and de-represses YAP1 to drive potent activity against neuroendocrine prostate cancer

Lysine-specific demethylase 1 (LSD1 or KDM1A ) has emerged as a critical mediator of tumor progression in metastatic castration-resistant prostate cancer (mCRPC). Among mCRPC subtypes, neuroendocrine prostate cancer (NEPC) is an exceptionally aggressive variant driven by lineage plasticity, an adaptive resistance mechanism to androgen receptor axis-targeted therapies. Our study shows that LSD1 expression is elevated in NEPC and associated with unfavorable clinical outcomes. Using genetic approaches, we validated the on-target effects of LSD1 inhibition across various models. We investigated the therapeutic potential of bomedemstat, an orally bioavailable, irreversible LSD1 inhibitor with low nanomolar potency. Our findings demonstrate potent antitumor activity against CRPC models, including tumor regressions in NEPC patient-derived xenografts. Mechanistically, our study uncovers that LSD1 inhibition suppresses the neuronal transcriptional program by downregulating ASCL1 through disrupting LSD1:INSM1 interactions and de-repressing YAP1 silencing. Our data support the clinical development of LSD1 inhibitors for treating CRPC - especially the aggressive NE phenotype.

Statement of Significance

Neuroendocrine prostate cancer presents a clinical challenge due to the lack of effective treatments. Our research demonstrates that bomedemstat, a potent and selective LSD1 inhibitor, effectively combats neuroendocrine prostate cancer by downregulating the ASCL1- dependent NE transcriptional program and re-expressing YAP1.

FASN Gene Methylation is Associated with Fatty Acid Synthase Expression and Clinical-genomic Features of Prostate Cancer

Fatty acid synthase (FASN) catalyzes the synthesis of long-chain saturated fatty acids and is overexpressed during prostatic tumorigenesis, where it is the therapeutic target in several ongoing trials. However, the mechanism of FASN upregulation in prostate cancer remains unclear. Here, we examine FASN gene CpG methylation pattern by InfiniumEPIC profiling and whole-genome bisulfite sequencing across multiple racially diverse primary and metastatic prostate cancer cohorts, comparing with FASN protein expression as measured by digitally quantified IHC assay and reverse phase protein array analysis or FASN gene expression. We demonstrate that the FASN gene body is hypomethylated and overexpressed in primary prostate tumors compared with benign tissue, and FASN gene methylation is significantly inversely correlated with FASN protein or gene expression in both primary and metastatic prostate cancer. Primary prostate tumors with ERG gene rearrangement have increased FASN expression and we find evidence of FASN hypomethylation in this context. FASN expression is also significantly increased in prostate tumors from carriers of the germline HOXB13 G84E mutation compared with matched controls, consistent with a report that HOXB13 may contribute to epigenetic regulation of FASN in vitro. However, in contrast to previous studies, we find no significant association of FASN expression or methylation with self-identified race in models that include ERG status across two independent primary tumor cohorts. Taken together, these data support a potential epigenetic mechanism for FASN regulation in the prostate which may be relevant for selecting patients responsive to FASN inhibitors.

SIGNIFICANCE

Here, we leverage multiple independent primary and metastatic prostate cancer cohorts to demonstrate that FASN gene body methylation is highly inversely correlated with FASN gene and protein expression. This finding may shed light on epigenetic mechanisms of FASN regulation in prostate cancer and provides a potentially useful biomarker for selecting patients in future trials of FASN inhibitors.

Characterization of HOXB13 expression patterns in localized and metastatic castration-resistant prostate cancer

HOXB13 is a key lineage homeobox transcription factor that plays a critical role in the differentiation of the prostate gland. Several studies have suggested that HOXB13 alterations may be involved in prostate cancer development and progression. Despite its potential biological relevance, little is known about the expression of HOXB13 across the disease spectrum of prostate cancer. To this end, we validated a HOXB13 antibody using genetic controls and investigated HOXB13 protein expression in murine and human developing prostates, localized prostate cancers, and metastatic castration-resistant prostate cancers. We observed that HOXB13 expression increases during later stages of murine prostate development. All localized prostate cancers showed HOXB13 protein expression. Interestingly, lower HOXB13 expression levels were observed in higher-grade tumors, although no significant association between HOXB13 expression and recurrence or disease-specific survival was found. In advanced metastatic prostate cancers, HOXB13 expression was retained in the majority of tumors. While we observed lower levels of HOXB13 protein and mRNA levels in tumors with evidence of lineage plasticity, 84% of androgen receptor-negative castration-resistant prostate cancers and neuroendocrine prostate cancers (NEPCs) retained detectable levels of HOXB13. Notably, the reduced expression observed in NEPCs was associated with a gain of HOXB13 gene body CpG methylation. In comparison to the commonly used prostate lineage marker NKX3.1, HOXB13 showed greater sensitivity in detecting advanced metastatic prostate cancers. Additionally, in a cohort of 837 patients, 383 with prostatic and 454 with non-prostatic tumors, we found that HOXB13 immunohistochemistry had a 97% sensitivity and 99% specificity for prostatic origin. Taken together, our studies provide valuable insight into the expression pattern of HOXB13 during prostate development and cancer progression. Furthermore, our findings support the utility of HOXB13 as a diagnostic biomarker for prostate cancer, particularly to confirm the prostatic origin of advanced metastatic castration-resistant tumors. © 2023 The Pathological Society of Great Britain and Ireland.

ASSESSMENT OF CELL SURFACE TARGETS IN METASTATIC PROSTATE CANCER: EXPRESSION LANDSCAPE AND MOLECULAR CORRELATES

Therapeutic approaches targeting proteins on the surface of cancer cells have emerged as an important strategy for precision oncology. To fully capitalize on the potential impact of drugs targeting surface proteins, detailed knowledge about the expression patterns of the target proteins in tumor tissues is required. In castration-resistant prostate cancer (CRPC), agents targeting prostate-specific membrane antigen (PSMA) have demonstrated clinical activity. However, PSMA expression is lost in a significant number of CRPC tumors, and the identification of additional cell surface targets is necessary in order to develop new therapeutic approaches. Here, we performed a comprehensive analysis of the expression and co-expression patterns of trophoblast cell-surface antigen 2 (TROP2), delta-like ligand 3 (DLL3), and carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) in CRPC samples from a rapid autopsy cohort. We show that DLL3 and CEACAM5 exhibit the highest expression in neuroendocrine prostate cancer (NEPC), while TROP2 is expressed across different CRPC molecular subtypes, except for NEPC. We observed variable intra-tumoral and inter-tumoral heterogeneity and no dominant metastatic site predilections for TROP2, DLL3, and CEACAM5. We further show that AR amplifications were associated with higher expression of PSMA and TROP2 but lower DLL3 and CEACAM5 levels. Conversely, PSMA and TROP2 expression was lower in RB1-altered tumors. In addition to genomic alterations, we demonstrate a tight correlation between epigenetic states, particularly histone H3 lysine 27 methylation (H3K27me3) at the transcriptional start site and gene body of TACSTD2 (encoding TROP2), DLL3, and CEACAM5, and their respective protein expression in CRPC patient-derived xenografts. Collectively, these findings provide novel insights into the patterns and determinants of expression of TROP2, DLL3, and CEACAM5 with important implications for the clinical development of cell surface targeting agents in CRPC.

Supraphysiological Androgens Promote the Tumor Suppressive Activity of the Androgen Receptor through cMYC Repression and Recruitment of the DREAM Complex

The androgen receptor (AR) pathway regulates key cell survival programs in prostate epithelium. The AR represents a near-universal driver and therapeutic vulnerability in metastatic prostate cancer, and targeting AR has a remarkable therapeutic index. Though most approaches directed toward AR focus on inhibiting AR signaling, laboratory and now clinical data have shown that high dose, supraphysiological androgen treatment (SPA) results in growth repression and improved outcomes in subsets of patients with prostate cancer. A better understanding of the mechanisms contributing to SPA response and resistance could help guide patient selection and combination therapies to improve efficacy. To characterize SPA signaling, we integrated metrics of gene expression changes induced by SPA together with cistrome data and protein-interactomes. These analyses indicated that the dimerization partner, RB-like, E2F, and multivulval class B (DREAM) complex mediates growth repression and downregulation of E2F targets in response to SPA. Notably, prostate cancers with complete genomic loss of RB1 responded to SPA treatment, whereas loss of DREAM complex components such as RBL1/2 promoted resistance. Overexpression of MYC resulted in complete resistance to SPA and attenuated the SPA/AR-mediated repression of E2F target genes. These findings support a model of SPA-mediated growth repression that relies on the negative regulation of MYC by AR leading to repression of E2F1 signaling via the DREAM complex. The integrity of MYC signaling and DREAM complex assembly may consequently serve as determinants of SPA responses and as pathways mediating SPA resistance.

SIGNIFICANCE

Determining the molecular pathways by which supraphysiological androgens promote growth arrest and treatment responses in prostate cancer provides opportunities for biomarker-selected clinical trials and the development of strategies to augment responses.

Reversible epigenetic alterations mediate PSMA expression heterogeneity in advanced metastatic prostate cancer

Prostate-specific membrane antigen (PSMA) is an important cell surface target in prostate cancer. There are limited data on the heterogeneity of PSMA tissue expression in metastatic castration-resistant prostate cancer (mCRPC). Furthermore, the mechanisms regulating PSMA expression (encoded by the FOLH1 gene) are not well understood. Here, we demonstrate that PSMA expression is heterogeneous across different metastatic sites and molecular subtypes of mCRPC. In a rapid autopsy cohort in which multiple metastatic sites per patient were sampled, we found that 13 of 52 (25%) cases had no detectable PSMA and 23 of 52 (44%) cases showed heterogeneous PSMA expression across individual metastases, with 33 (63%) cases harboring at least 1 PSMA-negative site. PSMA-negative tumors displayed distinct transcriptional profiles with expression of druggable targets such as MUC1. Loss of PSMA was associated with epigenetic changes of the FOLH1 locus, including gain of CpG methylation and loss of histone 3 lysine 27 (H3K27) acetylation. Treatment with histone deacetylase (HDAC) inhibitors reversed this epigenetic repression and restored PSMA expression in vitro and in vivo. Collectively, these data provide insights into the expression patterns and regulation of PSMA in mCRPC and suggest that epigenetic therapies - in particular, HDAC inhibitors - can be used to augment PSMA levels.

Nucleosome Patterns in Circulating Tumor DNA Reveal Transcriptional Regulation of Advanced Prostate Cancer Phenotypes

Advanced prostate cancers comprise distinct phenotypes, but tumor classification remains clinically challenging. Here, we harnessed circulating tumor DNA (ctDNA) to study tumor phenotypes by ascertaining nucleosome positioning patterns associated with transcription regulation. We sequenced plasma ctDNA whole genomes from patient-derived xenografts representing a spectrum of androgen receptor active (ARPC) and neuroendocrine (NEPC) prostate cancers. Nucleosome patterns associated with transcriptional activity were reflected in ctDNA at regions of genes, promoters, histone modifications, transcription factor binding, and accessible chromatin. We identified the activity of key phenotype-defining transcriptional regulators from ctDNA, including AR, ASCL1, HOXB13, HNF4G, and GATA2. To distinguish NEPC and ARPC in patient plasma samples, we developed prediction models that achieved accuracies of 97% for dominant phenotypes and 87% for mixed clinical phenotypes. Although phenotype classification is typically assessed by IHC or transcriptome profiling from tumor biopsies, we demonstrate that ctDNA provides comparable results with diagnostic advantages for precision oncology.

SIGNIFICANCE

This study provides insights into the dynamics of nucleosome positioning and gene regulation associated with cancer phenotypes that can be ascertained from ctDNA. New methods for classification in phenotype mixtures extend the utility of ctDNA beyond assessments of somatic DNA alterations with important implications for molecular classification and precision oncology. This article is highlighted in the In This Issue feature, p. 517.

Genomic Characterization of Prostatic Basal Cell Carcinoma

Basal cell carcinoma (BCC) of the prostate is a rare tumor. Compared with the more common acinar adenocarcinoma (AAC) of the prostate, BCCs show features of basal cell differentiation and are thought to be biologically distinct from AAC. The spectrum of molecular alterations of BCC has not been comprehensively described, and genomic studies are lacking. Herein, whole genome sequencing was performed on archival formalin-fixed, paraffin-embedded specimens of two cases with BCC. Prostatic BCCs were characterized by an overall low copy number and mutational burden. Recurrent copy number loss of chromosome 16 was observed. In addition, putative driver gene alterations in KIT, DENND3, PTPRU, MGA, and CYLD were identified. Mechanistically, depletion of the CYLD protein resulted in increased proliferation of prostatic basal cells in vitro. Collectively, these studies show that prostatic BCC displays distinct genomic alterations from AAC and highlight a potential role for loss of chromosome 16 in the pathogenesis of this rare tumor type.

Mortality in Hip Fracture Patients During the COVID-19 Pandemic: A Retrospective Analysis in a District General Hospital in the United Kingdom

Introduction

Hip fracture is commonly seen in elderly patients because of low-energy trauma. It carries significant morbidity and mortality. Scoring systems such as the Nottingham hip fracture score (NHFS) have shown a good correlation with increased mortality as the value of these scores increases. In our study, we aim to ascertain the hip fracture mortality in our population, compare the mortality in hip fractures compared to previously reported figures in literature and nationally reported figures during the first year of the COVID-19 pandemic, and also ascertain the usefulness of NHFS in predicting mortality in hip fractures.

Methods

We gathered mortality data on hip fracture patients admitted to our unit from January 1, 2020 to December 31, 2020. NHFS was calculated for all patients and the 30-day mortality rate was compared to previously reported hip fracture mortality rates using the standard mortality ratio (SMR). One-year mortality was stratified by placing patients in high and low NHFS groups. The log-rank test was used to compare hip fracture survival at one month and at one year in the high NHFS (NHFS >4) group and low NHFS group (NHFS value 4 or below). Additionally, a log-rank test was used to compare one-month and one-year survival in hip fractures managed with hemiarthroplasty, dynamic hip screw and intramedullary nail.

Results

In 2020, 388 patients were admitted with hip fractures to our unit. The crude mortality rate was 3.9% at 30 days and 20.88% at one year. Compared to the National Hip Fracture Database report for 2020, the incidence risk ratio for mortality was 0.46 (p-value<0.05). The SMR at 30 days was 0.34 (CI=0.17-0.51) and the SMR at one year was 0.63 (CI=0.49-0.77). The survival rate was higher at 30 days and one year in the low NHFS group compared to the high NHFS group (p-value<0.01). The survival rate at one month and one year were similar in groups managed with hemiarthroplasty, dynamic hip screws, and intramedullary nails (p-value>0.05).

Conclusions

Hip fracture mortality has been decreasing steadily and we noted a lower rate of hip fracture mortality compared to figures reported previously as per NHFS studies even though the study was conducted during the COVID-19 pandemic period. We also noted lower 30-day mortality in our hospital as compared to the national 30-day mortality rate for hip fracture patients in 2020.

Impact of COVID-19 Pandemic on the Length of Hospital Stay in Hip Fracture Patients: A Single Centre Study

Background

Hip fracture is a debilitating injury, especially in older individuals, which is associated with significant morbidity and mortality. In recent decades, there has been a great focus on early rehabilitation and discharge after hip fractures. The aim of such efforts is to minimize the financial and clinical burden of this condition. We conducted our study during the COVID-19 pandemic and compared the length of hospital stay (LOS) in 2020 to the LOS in 2019. Additionally, we studied the factors which may impact the LOS, such as premorbid status according to established scoring systems, the type of fracture, an operation performed, and time to surgery.

Methods

We collected the data regarding the length of stay (in days) for all hip fracture patients admitted to our unit from 1^st January 2019 until 31^st December 2020. We then compared the mean LOS for both years using the t-test. We calculated the Nottingham Hip Fracture Score (NHFS) and American Society of Anaesthesiologists (ASA) scores for patients admitted in 2020 and calculated the correlation between increasing values of these scores and the LOS. We also compared the mean LOS for patients admitted in 2020 based on the type of fracture and type of management. We studied the correlation between the time to surgery and the LOS for patients admitted in 2020.

Results

Three hundred and eighty-eight patients were admitted with hip fractures in 2020, and 452 were admitted in 2019. LOS in 2020 was significantly lower (23.39 days) compared to 2019 (31.36 days) with p<0.01. While evaluating data from 2019, it was noted that there was a small positive correlation between LOS and NHFS (r=0.231, p<0.001) and LOS and ASA (r=0.18, p<0.001). The mean LOS for intracapsular fractures was noted to be lower than that of extracapsular fractures, but this was not statistically significant (p=0.17). An ANOVA test showed that the mean LOS for patients undergoing hemiarthroplasty, dynamic hip screws (DHS), and intramedullary nails (IMN) was significantly longer than for patients managed with total hip replacement or patients managed non-operatively (F=3.551, p<0.01).

Conclusion

Hip fracture patients admitted to our department were discharged quicker during the first year of the COVID-19 pandemic. The LOS for hip fractures increases with an increase in their NHFS or ASA scores. Extracapsular and intracapsular fractures lead to roughly the same periods of inpatient stay. Patients undergoing hemiarthroplasty, DHS, or IMN stay longer in the hospital compared to other treatment modalities.

Comparison of Lateral and Crossed K-wires for Paediatric Supracondylar Fractures: A Retrospective Cohort Study

Background

Supracondylar elbow fractures occur most frequently in children aged five to seven years and have equal incidence in both genders. They are classified as flexion or extension type injuries with extension type being more common. We aimed to ascertain radiological stability with lateral and crossed wires in this study. We also identified any complications after operative management of these injuries.

Methods

As part of this retrospective cohort study, we identified all patients who presented with this injury from January 1, 2020, until February 28, 2022. Basic demographic data and type of operation were noted. Baumann angle (BA) and lateral capitellohumeral angle (LCHA) were measured intra-operatively and x-rays were done at the final clinic appointment. The mean of these angles in lateral and crossed wire groups was compared using paired sample t-test. Unpaired t-test was used to compare the means of both groups with normal values for these angles based on previous studies (BA=71.5±6.2 degrees, LCHA= 50.8±6 degrees).

Results

Fifty patients were admitted during this period. Thirty-three patients had lateral wires and 17 had crossed wires for fixation. No significant change was noted in the mean BA and mean LCHA in both groups on x-rays done intra-operatively and final clinic follow-up (no loss of reduction). No significant difference was noted between BA and LCHA noted for both groups at the final clinic follow-up with previous studies outlining normal values for these angles. No cases of iatrogenic neurovascular injury were identified. Four patients (8%) were referred to physiotherapy due to stiffness.

Conclusion

Both lateral and crossed wire configurations led to achievement of good radiological stability with BA and LCHA within normal limits. No loss of reduction was noted with both techniques and no risk of iatrogenic nerve injuries was noted in experienced hands.

Spaceflight Analogue Culture Enhances the Host-Pathogen Interaction Between Salmonella and a 3-D Biomimetic Intestinal Co-Culture Model

Physical forces associated with spaceflight and spaceflight analogue culture regulate a wide range of physiological responses by both bacterial and mammalian cells that can impact infection. However, our mechanistic understanding of how these environments regulate host-pathogen interactions in humans is poorly understood. Using a spaceflight analogue low fluid shear culture system, we investigated the effect of Low Shear Modeled Microgravity (LSMMG) culture on the colonization of Salmonella Typhimurium in a 3-D biomimetic model of human colonic epithelium containing macrophages. RNA-seq profiling of stationary phase wild type and Δhfq mutant bacteria alone indicated that LSMMG culture induced global changes in gene expression in both strains and that the RNA binding protein Hfq played a significant role in regulating the transcriptional response of the pathogen to LSMMG culture. However, a core set of genes important for adhesion, invasion, and motility were commonly induced in both strains. LSMMG culture enhanced the colonization (adherence, invasion and intracellular survival) of Salmonella in this advanced model of intestinal epithelium using a mechanism that was independent of Hfq. Although S. Typhimurium Δhfq mutants are normally defective for invasion when grown as conventional shaking cultures, LSMMG conditions unexpectedly enabled high levels of colonization by an isogenic Δhfq mutant. In response to infection with either the wild type or mutant, host cells upregulated transcripts involved in inflammation, tissue remodeling, and wound healing during intracellular survival. Interestingly, infection by the Δhfq mutant led to fewer transcriptional differences between LSMMG- and control-infected host cells relative to infection with the wild type strain. This is the first study to investigate the effect of LSMMG culture on the interaction between S. Typhimurium and a 3-D model of human intestinal tissue. These findings advance our understanding of how physical forces can impact the early stages of human enteric salmonellosis.

Response to supraphysiological testosterone is predicted by a distinct androgen receptor cistrome

The androgen receptor (AR) is a master transcription factor that regulates prostate cancer (PC) development and progression. Inhibition of AR signaling by androgen deprivation is the first-line therapy with initial efficacy for advanced and recurrent PC. Paradoxically, supraphysiological levels of testosterone (SPT) also inhibit PC progression. However, as with any therapy, not all patients show a therapeutic benefit, and responses differ widely in magnitude and duration. In this study, we evaluated whether differences in the AR cistrome before treatment can distinguish between SPT-responding (R) and -nonresponding (NR) tumors. We provide the first preclinical evidence to our knowledge that SPT-R tumors exhibit a distinct AR cistrome when compared with SPT-NR tumors, indicating a differential biological role of the AR. We applied an integrated analysis of ChIP-Seq and RNA-Seq to the pretreatment tumors and identified an SPT-R signature that distinguishes R and NR tumors. Because transcriptomes of SPT-treated clinical specimens are not available, we interrogated available castration-resistant PC (CRPC) transcriptomes and showed that the SPT-R signature is associated with improved survival and has the potential to identify patients who would respond to SPT. These findings provide an opportunity to identify the subset of patients with CRPC who would benefit from SPT therapy.

Comprehensive assessment of anaplastic lymphoma kinase in localized and metastatic prostate cancer reveals targetable alterations

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase with genomic and expression changes in many solid tumors. ALK inhibition is first line therapy for lung cancers with ALK alterations, and an effective therapy in other tumor types, but has not been well-studied in prostate cancer. Here, we aim to delineate the role of ALK genomic and expression changes in primary and metastatic prostate cancer. We determined ALK expression by immunohistochemistry and RNA-Seq, and genomic alterations by NGS. We assessed functional consequences of ALK overexpression and pharmacological ALK inhibition by cell proliferation and cell viability assays. Among 372 primary prostate cancer cases we identified one case with uniformly high ALK protein expression. Genomic analysis revealed a SLC45A3-ALK fusion which promoted oncogenesis in in vitro assays. We observed ALK protein expression in 5/52 (9%) of metastatic prostate cancer cases, of which 4 of 5 had neuroendocrine features. ALK-expressing neuroendocrine prostate cancer had a distinct transcriptional program, and earlier disease progression. An ALK-expressing neuroendocrine prostate cancer model was sensitive to pharmacological ALK inhibition. In summary, we found that ALK overexpression is rare in primary prostate cancer, but more frequent in metastatic prostate cancers with neuroendocrine differentiation. Further, ALK fusions similar to lung cancer are an occasional driver in prostate cancer. Our data suggest that ALK-directed therapies could be an option in selected patients with advanced prostate cancer.

A Prospective Study Assessing Wound Complications in a Series of Foot and Ankle Patients Treated With Enoxaparin: A Baseline for Future Studies

Background and objective

Low-molecular-weight heparin (LMWH) prophylaxis has now become the gold-standard practice in patients requiring lower limb immobilization. We had noticed an increase in the incidence of wound-healing problems at our center, and the severity of the problems was found to be worse in patients undergoing foot and ankle surgery since we had adopted this practice. In this study, we aimed to describe the incidence and severity of wound-healing problems in this group of patients.

Methods

This was a prospective study and we collected data on the frequency and severity of wound problems occurring in patients undergoing a variety of foot and ankle operations. All patients underwent a standard agreed-on method of wound closure and dressings. Wounds were reviewed after two weeks and wound characteristics were noted using a rigid proforma. The primary outcome measure was to determine the incidence of delayed wound healing (DWH) and wound infections requiring antibiotics. Secondary outcomes were the characteristics of each delayed-healing wound.

Results

A total of 158 patients met the inclusion criteria of the study. One patient was not given postoperative LMWH and was excluded from the final analysis. Seven patients (4.5%) were noted to have DWH and four patients (2.6%) had a wound infection at the two-week postoperative follow-up. None of the patients required a second operation. Among patients with wound-healing problems, wound contour irregularities were noted in 51% and margin separation was noted in 65%.

Conclusion

The overall incidence of wound-healing problems such as DWH and wound infections was low in patients receiving prophylactic LMWH for foot and ankle surgery. Where postoperative wound problems did occur, these were associated with poor wound characteristics such as margin separation or contour irregularity. Further studies should be conducted to ascertain if the use of LMWH leads to problems with wound appearance.

Genomic attributes of homology-directed DNA repair deficiency in metastatic prostate cancer

Cancers with homology-directed DNA repair (HRR) deficiency exhibit high response rates to poly(ADP-ribose) polymerase inhibitors (PARPi) and platinum chemotherapy. Though mutations disrupting BRCA1 and BRCA2 associate with HRR deficiency (HRRd), patterns of genomic aberrations and mutation signatures may be more sensitive and specific indicators of compromised repair. Here, we evaluated whole-exome sequences from 418 metastatic prostate cancers (mPCs) and determined that one-fifth exhibited genomic characteristics of HRRd that included Catalogue Of Somatic Mutations In Cancer mutation signature 3. Notably, a substantial fraction of tumors with genomic features of HRRd lacked biallelic loss of a core HRR-associated gene, such as BRCA2. In this subset, HRRd associated with loss of chromodomain helicase DNA binding protein 1 but not with mutations in serine-protein kinase ATM, cyclin dependent kinase 12, or checkpoint kinase 2. HRRd genomic status was strongly correlated with responses to PARPi and platinum chemotherapy, a finding that supports evaluating biomarkers reflecting functional HRRd for treatment allocation.

Reciprocal YAP1 loss and INSM1 expression in neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is a rare but aggressive histologic variant of prostate cancer that responds poorly to androgen deprivation therapy. Hybrid NEPC-adenocarcinoma (AdCa) tumors are common, often eluding accurate pathologic diagnosis and requiring ancillary markers for classification. We recently performed an outlier-based meta-analysis across a number of independent gene expression microarray datasets to identify novel markers that differentiate NEPC from AdCa, including up-regulation of insulinoma-associated protein 1 (INSM1) and loss of Yes-associated protein 1 (YAP1). Here, using diverse cancer gene expression datasets, we show that Hippo pathway-related genes, including YAP1, are among the top down-regulated gene sets with expression of the neuroendocrine transcription factors, including INSM1. In prostate cancer cell lines, transgenic mouse models, and human prostate tumor cohorts, we confirm that YAP1 RNA and YAP1 protein expression are silenced in NEPC and demonstrate that the inverse correlation of INSM1 and YAP1 expression helps to distinguish AdCa from NEPC. Mechanistically, we find that YAP1 loss in NEPC may help to maintain INSM1 expression in prostate cancer cell lines and we further demonstrate that YAP1 silencing likely occurs epigenetically, via CpG hypermethylation near its transcriptional start site. Taken together, these data nominate two additional markers to distinguish NEPC from AdCa and add to data from other tumor types suggesting that Hippo signaling is tightly reciprocally regulated with neuroendocrine transcription factor expression. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

1357 Ankle Blocks: Improving Day Case Efficiency

Introduction

The COVID pandemic has exerted unprecedented pressure on hospital resources. Resulting in cancellation of elective operative services, increased patient waiting lists, limited surgical training opportunities along with reduced availability of staff, theatre, and in-patient bed capacity. A novel approach for day case forefoot surgery under ankle block, to mitigate the pandemic service limitations without compromising care, was developed.

Method

This is a 3-month, multi-centre, prospective cohort study evaluating the novel ankle block day case forefoot surgery pathway. Patients had a minimum of three months clinical follow up with outcome scores. They were matched to a cohort undergoing similar surgery prior to the COVID pandemic.

Results

The utilisation of an ankle block pathway resulted in an average reduction of inpatient stay by 2 days per patient. Over the study period conservative savings of £26,659 were calculated. Anecdotally we observed a reduction in morbidity (wound complications, SSI’s) although not statistically significant.

Conclusions

Our novel surgical pathway has enabled continued elective operating for procedures that previously required hospital admission during a period of severe restrictions within the NHS. We observed significant reductions in cost, surgical inpatient bed utilisation and total operative time with staff, resource, and time savings. We hypothesise that prehabilitation with physiotherapy, ankle instead of thigh tourniquets and early mobilisation may have contributed to improved morbidity scores. The findings of this project have implications for training, upper limb services and are transferrable as a template to improve service efficiency while maintaining high quality care.

Suture-Button Versus Syndesmotic Screw Fixation of Ankle Fractures: A Comparative Retrospective Review Over One Year

Background Syndesmotic fixation is essential in the management of unstable ankle fractures with syndesmotic disruption. It can be achieved either by rigid fixation with screws or dynamic fixation with suture-button devices. Syndesmosis screws are considered the gold standard for the stabilisation and fixation of distal tibiofibular syndesmotic injuries. We use both types of devices in our unit for the stabilisation of syndesmotic injuries. In our department, Arthrex TightRope® (Arthrex, Naples, FL) is the preferred suture-button device for the dynamic fixation of distal tibiofibular syndesmosis. Some studies have reported better outcomes with the use of suture-button devices. In this study, we aim to compare the outcomes with the use of both these devices. Methodology This retrospective cohort study was conducted from 1 June 2019 until 31 May 2020 which included all patients who underwent syndesmotic fixation. Data were collected from the Northern Ireland Electronic Care Record and the Northern Ireland Picture Archiving and Communication System. Primary outcomes included reoperation rates due to failure of syndesmotic hardware. Secondary outcomes included the comparison of complications (e.g. infection, wound problems, or loss of reduction) radiographic fixation/stability, duration of follow-up, and significant ongoing symptoms at the time of discharge from the clinic. Results A total of 53 patients underwent syndesmotic stabilisation during this period. In total, 34 patients underwent fixation with TightRope and 19 underwent syndesmotic screw fixation. Three patients (9%) had reoperation due to any cause in the TightRope group compared to four patients (21%) in the syndesmotic screw group. All four patients in the syndesmotic screws group underwent implant removal due to failure or symptoms due to implant. Only one patient (3%) in the TightRope group underwent implant removal due to ongoing pain [the other two (6%) patients included one with lateral ankle abscess and one with long distal fibula screws, both unrelated to the use of TightRope and TightRope left in situ at reoperation]. Rediastasis was reported in one (5.2%) patient with syndesmotic screws. The median duration of follow-up was 82 days in the syndesmotic screw group compared to 77.5 days in the TightRope group. Conclusions Based on our data, we report a lower incidence of implant-related problems and the need for implant removal with the use of TightRope. Quicker return to weight-bearing and slightly better radiographic stabilisation were noted as well. Our study has its limitations in terms of a small number of patients and the absence of functional outcomes as these were not routinely recorded at the time of discharge from the clinic.

RNA splicing factors SRRM3 and SRRM4 distinguish molecular phenotypes of castration-resistant neuroendocrine prostate cancer

Neuroendocrine (NE) differentiation in metastatic castration-resistant prostate cancer (mCRPC) is an increasingly common clinical feature arising from cellular plasticity. We recently characterized two mCRPC phenotypes with NE features: androgen receptor (AR)-positive NE-positive amphicrine prostate cancer (AMPC) and AR-negative small cell or neuroendocrine prostate cancer (SCNPC). Here, we interrogated the regulation of RE1-silencing transcription factor (REST), a transcriptional repressor of neuronal genes, and elucidated molecular programs driving AMPC and SCNPC biology. Analysis of prostate cancer (PC) cell lines, mCRPC specimens, and LuCaP patient-derived xenograft models detected alternative splicing of REST to REST4 and attenuated REST repressor activity in AMPC and SCNPC. The REST locus was also hypermethylated and REST expression was reduced in SCNPC. While serine/arginine repetitive matrix protein 4 (SRRM4) was previously implicated in alternative splicing of REST in mCRPC, we detected SRRM3 expression in REST4-positive, SRRM4-negative AMPC and SCNPC. In CRPC cell lines, SRRM3 induced alternative splicing of REST to REST4 and exacerbated the expression of REST-repressed genes. Furthermore, SRRM3 and SRRM4 expression defined molecular subsets of AMPC and SCNPC across species and tumor types. Two AMPC phenotypes and three SCNPC phenotypes were characterized, denoted either by REST attenuation and ASCL1 activity or by progressive activation of neuronal transcription factor programs, respectively. These results nominate SRRM3 as the principal REST splicing factor expressed in early NE differentiation and provide a framework to molecularly classify diverse NE phenotypes in mCRPC.

Closing the UK care home data gap - methodological challenges and solutions

UK care home residents are invisible in national datasets. The COVID-19 pandemic has exposed data failings that have hindered service development and research for years. Fundamental gaps, in terms of population and service demographics coupled with difficulties identifying the population in routine data are a significant limitation. These challenges are a key factor underpinning the failure to provide timely and responsive policy decisions to support care homes. In this commentary we propose changes that could address this data gap, priorities include: (1) Reliable identification of care home residents and their tenure; (2) Common identifiers to facilitate linkage between data sources from different sectors; (3) Individual-level, anonymised data inclusive of mortality irrespective of where death occurs; (4) Investment in capacity for large-scale, anonymised linked data analysis within social care working in partnership with academics; (5) Recognition of the need for collaborative working to use novel data sources, working to understand their meaning and ensure correct interpretation; (6) Better integration of information governance, enabling safe access for legitimate analyses from all relevant sectors; (7) A core national dataset for care homes developed in collaboration with key stakeholders to support integrated care delivery, service planning, commissioning, policy and research. Our suggestions are immediately actionable with political will and investment. We should seize this opportunity to capitalise on the spotlight the pandemic has thrown on the vulnerable populations living in care homes to invest in data-informed approaches to support care, evidence-based policy making and research.

Resistance to androgen receptor signaling inhibition does not necessitate development of neuroendocrine prostate cancer

Resistance to AR signaling inhibitors (ARSis) in a subset of metastatic castration-resistant prostate cancers (mCRPCs) occurs with the emergence of AR^– neuroendocrine prostate cancer (NEPC) coupled with mutations/deletions in PTEN, TP53, and RB1 and the overexpression of DNMTs, EZH2, and/or SOX2. To resolve whether the lack of AR is the driving factor for the emergence of the NE phenotype, molecular, cell, and tumor biology analyses were performed on 23 xenografts derived from patients with PC, recapitulating the full spectrum of genetic alterations proposed to drive NE differentiation. Additionally, phenotypic response to CRISPR/Cas9-mediated AR KO in AR⁺ CRPC cells was evaluated. These analyses document that (a) ARSi-resistant NEPC developed without androgen deprivation treatment; (b) ARS in ARSi-resistant AR⁺/NE⁺ double-positive “amphicrine” mCRPCs did not suppress NE differentiation; (c) the lack of AR expression did not necessitate acquiring a NE phenotype, despite concomitant mutations/deletions in PTEN and TP53, and the loss of RB1 but occurred via emergence of an AR^–/NE^– double-negative PC (DNPC); (d) despite DNPC cells having homogeneous genetic driver mutations, they were phenotypically heterogeneous, expressing basal lineage markers alone or in combination with luminal lineage markers; and (e) AR loss was associated with AR promoter hypermethylation in NEPCs but not in DNPCs.

Frailty among Older Adults and Its Distribution in England

Background: Information on the spatial distribution of the frail population is crucial to inform service planning in health and social care. Objectives: To estimate small-area frailty prevalence among older adults using survey data. To assess whether prevalence differs between urban, rural, coastal and inland areas of England. Design: Using data from the English Longitudinal Study of Ageing (ELSA), ordinal logistic regression was used to predict the probability of frailty, according to age, sex and area deprivation. Probabilities were applied to demographic and economic information in 2020 population projections to estimate the district-level prevalence of frailty. Results: The prevalence of frailty in adults aged 50+ (2020) in England was estimated to be 8.1 [95% CI 7.3-8.8]%. We found substantial geographic variation, with the prevalence of frailty varying by a factor of 4.0 [3.5-4.4] between the most and least frail areas. A higher prevalence of frailty was found for urban than rural areas, and coastal than inland areas. There are widespread geographic inequalities in healthy ageing in England, with older people in urban and coastal areas disproportionately frail relative to those in rural and inland areas. Conclusions: Interventions aimed at reducing inequalities in healthy ageing should be targeted at urban and coastal areas, where the greatest benefit may be achieved.

Impact of social care supply on healthcare utilisation by older adults: a systematic review and meta-analysis

Objective

to investigate the impact of the availability and supply of social care on healthcare utilisation (HCU) by older adults in high income countries.

Design

systematic review and meta-analysis.

Data sources

medline, EMBASE, Scopus, Health Management Information Consortium, Cochrane Database of Systematic Reviews, NIHR Health Technology Assessment, NHS Economic Evaluation Database, Database of Abstracts of Reviews of Effectiveness, SCIE Online and ASSIA. Searches were carried out October 2016 (updated April 2017 and May 2018). (PROSPERO CRD42016050772).

Study selection

observational studies from high income countries, published after 2000 examining the relationship between the availability of social care (support at home or in care homes with or without nursing) and healthcare utilisation by adults >60 years. Studies were quality assessed.

Results

twelve studies were included from 11,757 citations; ten were eligible for meta-analysis. Most studies (7/12) were from the UK. All reported analysis of administrative data. Seven studies were rated good in quality, one fair and four poor. Higher social care expenditure and greater availability of nursing and residential care were associated with fewer hospital readmissions, fewer delayed discharges, reduced length of stay and expenditure on secondary healthcare services. The overall direction of evidence was consistent, but effect sizes could not be confidently quantified. Little evidence examined the influence of home-based social care, and no data was found on primary care use.

Conclusions

adequate availability of social care has the potential to reduce demand on secondary health services. At a time of financial stringencies, this is an important message for policy-makers.

When Planning Screw Fracture Fixation Why the 5.5 mm Screw is the Goldilocks Screw. An Observational Computer Tomographic Study of Fifth Metatarsal Bone Anatomy in a Sample of Patients

We wanted to verify our clinical experience that the 5.5 mm screw was ideal in the majority of fifth metatarsal fracture fixation. The size of a screw is important for the successful surgical treatment of these fractures in order to obtain the maximal stability while reducing the risk for iatrogenic fracture.A sample of patients undergoing computer tomographic imaging of the foot for investigation other than fifth metatarsal pathology were recruited. The parameters of the fifth metatarsal bone anatomy were measured.These parameters of the 5.5 mm screw were correlated with this data. The upper parameter (the diameter of the threads) was 5.5 and the lower parameter (the diameter of the shank) was 4.0 mm.Twenty seven patients were recruited.The proximal third internal diameter ranged from 3.6 to 7.0 mm with a mean of 5.0 mm. 93% of the metatarsals could easily accommodate the 5.5 mm screw. Two of the metatarsals had an internal diameter of < 4 mm (7%).It is our belief that the 5.5 mm screw may be used safely in the majority of patients with fifth metatarsal fractures.

The influence of pain on knee motion in patients with osteoarthritis undergoing total knee arthroplasty

Pain is the predominant symptom of degenerative knee arthritis and the main reason patients undergo total knee arthroplasty (TKA). Variation in patient response to pain has proved difficult to quantify. The effect of removing pain by testing TKA patients' range of motion (ROM) before and after the administration of anesthesia has not previously been analyzed. This study objectively quantifies the effect of eliminating pain on knee joint ROM for a typical group of TKA patients with osteoarthritis. We prospectively recruited 141 patients with osteoarthritis admitted for TKA to assess the inhibitory effect of pain on ROM. Passive maximum flexion, extension, and ROM were measured preoperatively before and after administration of anesthesia (spinal anesthetic followed by femoral and sciatic regional nerve blocks). Following pain abolition, passive maximum flexion increased by an average of 13.4 degrees (SD=11.9 degrees), passive maximum extension improved by an average of 3.0 degrees (SD=4.2 degrees), and passive ROM increased by an average of 16.4 degrees (SD=13.1 degrees). The change in each parameter was statistically significant (P<.0001). Improvements in flexion (P=.01) and ROM (P=.005) were significantly greater in women. Measurements taken before anesthesia reflect knee ROM that the patient will tolerate before pain becomes the limiting factor, while measurements taken after anesthesia is achieved suggest the knee ROM possible once pain is eliminated. Abolition of pain led to significant increases in knee flexion, extension, and ROM, suggesting that pain has a significant inhibitory effect on knee motion.

Making the most of routine data in palliative care research--a case study analysis of linked hospital and mortality data on cancer and heart failure patients in Scotland and Oxford

The research base of palliative care is growing rapidly, but despite methodological advances, some of the practical challenges of working with people at the end of life will persist. This means that analysis of routine data is arguably more important in studying palliative care than it is in other aspects of health services research. End-of-life researchers have been using the high-quality linked data from cancer registries for many years. This paper explores the value of a less well-known resource for palliative care research: linked mortality and hospital activity data. Two case studies are presented using information from Scotland (population 5.1 million) and the former Oxford region of England (population 2.5 million). The advantages and limitations of linked hospital and mortality data for research and service planning in palliative care are drawn out through analyses investigating hospital bed utilisation by people with cancer and heart failure and the influence of social deprivation on the use of hospital services in the last year of life. The use of such data deserves a higher profile.

A case of pseudoarthrosis of the lateral talar process and distal fibula in a professional athlete

We report a case of osteoarthritis of a pseudoarthrosis between the tip of the fibula and the lateral process of the talus. This was treated by excision of pseudoarthrosis with lateral ligament reconstruction.

Socioeconomic differences in service use, payment and receipt of illness-related benefits in the last year of life: findings from the British Household Panel Survey

BACKGROUND

Terminal illness presents a financial challenge to many households, but in Britain the situation should be eased by state benefits, such as attendance allowance, which is available to everyone in the last six months of life without means testing.

AIM

To investigate the use of health and social services, payments and benefit receipt by individuals in differing financial circumstances in the year before death.

METHODS

Analysis of individual level panel data for 1652 community-dwelling decedents from 12 waves of the British Household Panel Study (1991-2003).

RESULTS

In the year before death, over 90% of decedents saw their GP, and around one-third spent some time in hospital. More than 80% paid no fees for any services. Over a third of decedents aged over 65 reported financial strain, but only 13.9% of these were receiving attendance allowance. People who felt that they were having financial difficulties were more likely to be frequent attenders in primary care, taking age, health status and other factors into account (adjusted OR=1.9, 95% CI=1.3-2.6, P<0.001). Older age was associated with less use of primary, but not secondary care.

CONCLUSIONS

Financial strain was common, but benefit uptake low. Primary health care professionals saw nearly all decedents in their last year, and could play an important role in ensuring that the elderly and the less well off are aware of the services and benefits available to them.

The effect of physical activity advice given in routine primary care consultations: a systematic review

BACKGROUND

Recent evidence and recommendations suggest that physical activity health promotion should be aimed at persuading the whole population to adopt an active lifestyle. Intensive medical programmes aimed at promoting physical activity amongst those at risk are not effective at achieving this aim. Brief advice from primary care professionals to quit smoking has a small but, at a population level, important effect. Brief advice in primary care to adopt a more active lifestyle may be similarly effective. The aim of this review is to determine the effect of advice given in routine primary care consultations on levels of physical activity.

METHODS

A systematic review was carried out of trials assessing the effectiveness of advice given in routine primary care consultations. Data sources were four electronic databases (MEDLINE, EMBASE, Sport discus, Cochrane Library), and bibliographies of retrieved papers were searched. Experts were contacted.

RESULTS

Eight trials, with a total of 4747 participants, were identified; the majority were from the United States. Outcome measures varied considerably between trials, including continuous measures (e.g. duration of exercise) and dichotomous measures (e.g. being active), therefore statistical pooling was inappropriate. Two of the trials were cluster randomized controlled trials, the remainder were quasi-experimental. None of the trials fulfilled all of the predetermined quality criteria and selection bias in the nonrandomized studies may have exaggerated results. Four of the six trials that presented short-term (up to 8 weeks) results found advice to be effective; only one of the four trials with long-term follow-up (4-12 months) found a sustained effect. The two randomized controlled trials had negative short- and long-term results.

CONCLUSIONS

From the available evidence it appears that advice in routine primary care consultations is not an effective means of producing sustained increases in physical activity. However, these results may not be applicable to the United Kingdom, where the structure of primary care is unique. Quality research in UK primary care would be valuable.