An elusive prostate tumour: Metastatic microcystic cribriform carcinoma presenting with imaging-histologic discordance.

Microcystic adenocarcinoma is an uncommon histologic variant of prostate carcinoma. Despite its rarity, it has gained increasing recognition over the past decade for its diagnostic challenges and unclear prognostic significance. Herein, we describe a rare case of metastatic microcystic prostate adenocarcinoma, presenting with discordance between imaging and histologic findings. This report highlights the diagnostic and therapeutic challenges of this pathological entity and the importance of multidisciplinary collaboration in the management of intermediate-risk prostate cancer.

Cross-Species Extrapolation of Biological Data to Guide the Environmental Safety Assessment of Pharmaceuticals-The State of the Art and Future Priorities.

The extrapolation of biological data across species is a key aspect of biomedical research and drug development. In this context, comparative biology considerations are applied with the goal of understanding human disease and guiding the development of effective and safe medicines. However, the widespread occurrence of pharmaceuticals in the environment and the need to assess the risk posed to wildlife have prompted a renewed interest in the extrapolation of pharmacological and toxicological data across the entire tree of life. To address this challenge, a biological "read-across" approach, based on the use of mammalian data to inform toxicity predictions in wildlife species, has been proposed as an effective way to streamline the environmental safety assessment of pharmaceuticals. Yet, how effective has this approach been, and are we any closer to being able to accurately predict environmental risk based on known human risk? We discuss the main theoretical and experimental advancements achieved in the last 10 years of research in this field. We propose that a better understanding of the functional conservation of drug targets across species and of the quantitative relationship between target modulation and adverse effects should be considered as future research priorities. This pharmacodynamic focus should be complemented with the application of higher-throughput experimental and computational approaches to accelerate the prediction of internal exposure dynamics. The translation of comparative (eco)toxicology research into real-world applications, however, relies on the (limited) availability of experts with the skill set needed to navigate the complexity of the problem; hence, we also call for synergistic multistakeholder efforts to support and strengthen comparative toxicology research and education at a global level. Environ Toxicol Chem 2024;43:513-525. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Patients' experience of menopausal symptoms post-chemotherapy treatment for gestational trophoblastic neoplasia.

PURPOSE: We aimed to explore patient's experience of chemotherapy-induced menopausal symptoms; to ascertain how patients tried to alleviate their symptoms and how health professionals supported them in order to identify current unmet needs. METHODS: We designed a retrospective cross-sectional exploratory study of a sample of 11 women who received multi-agent combination chemotherapy for Gestational Trophoblastic Neoplasia. Postal surveys using the Greene Climacteric Scale (GCS) questionnaire followed up by semi-structured telephone interviews were used. Framework analysis technique was used to generate descriptions of patient's experiences. RESULTS: Symptoms of feeling tired or lacking in energy, loss of interest in sex, muscle and joint pains and difficulty in concentrating affected participants the most. The menopausal symptoms appear to be temporary; symptoms such as hot flushes and night sweats seem to subside with resumption of menses. Others are more gradual with some evidence that mental health takes longer to recover. Regarding potential symptoms, some women do not retain the information given to them at discharge following end of treatment, which GTD services need to take into consideration when supporting patients. CONCLUSION: Patients need to be more optimally prepared for post-chemotherapy recovery with each patient's needs and support being individually tailored. How information is discussed and disseminated needs improving to ensure patients retain the information they receive at discharge. Recommendations include the creation of menopause information booklet, alongside further developing virtual nurse-led follow up clinics post chemotherapy.

Comparison of Circulating Tumor DNA Assays for Molecular Residual Disease Detection in Early-Stage Triple-Negative Breast Cancer.

PURPOSE: Detection of circulating tumor DNA (ctDNA) in patients who have completed treatment for early-stage breast cancer is associated with a high risk of relapse, yet the optimal assay for ctDNA detection is unknown. EXPERIMENTAL DESIGN: The cTRAK-TN clinical trial prospectively used tumor-informed digital PCR (dPCR) assays for ctDNA molecular residual disease (MRD) detection in early-stage triple-negative breast cancer. We compared tumor-informed dPCR assays with tumor-informed personalized multimutation sequencing assays in 141 patients from cTRAK-TN. RESULTS: MRD was first detected by personalized sequencing in 47.9% of patients, 0% first detected by dPCR, and 52.1% with both assays simultaneously (P < 0.001; Fisher exact test). The median lead time from ctDNA detection to relapse was 6.1 months with personalized sequencing and 3.9 months with dPCR (P = 0.004, mixed-effects Cox model). Detection of MRD at the first time point was associated with a shorter time to relapse compared with detection at subsequent time points (median lead time 4.2 vs. 7.1 months; P = 0.02). CONCLUSIONS: Personalized multimutation sequencing assays have potential clinically important improvements in clinical outcome in the early detection of MRD.

PREDICT-GTN 2: Two-factor streamlined models match FIGO performance in gestational trophoblastic neoplasia.

OBJECTIVE: The International Federation of Gynecology and Obstetrics (FIGO) scoring system uses the sum of eight risk-factors to predict single-agent chemotherapy resistance in Gestational Trophoblastic Neoplasia (GTN). To improve ease of use, this study aimed to generate: (i) streamlined models that match FIGO performance and; (ii) visual-decision aids (nomograms) for guiding management. METHODS: Using training (n = 4191) and validation datasets (n = 144) of GTN patients from two UK specialist centres, logistic regression analysis generated two-factor models for cross-validation and exploration. Performance was assessed using true and false positive rate, positive and negative predictive values, Bland-Altman calibration plots, receiver operating characteristic (ROC) curves, decision-curve analysis (DCA) and contingency tables. Nomograms were developed from estimated model parameters and performance cross-checked upon the training and validation dataset. RESULTS: Three streamlined, two-factor models were selected for analysis: (i) M1, pre-treatment hCG + history of failed chemotherapy; (ii) M2, pre-treatment hCG + site of metastases and; (iii) M3, pre-treatment hCG + number of metastases. Using both training and validation datasets, these models showed no evidence of significant discordance from FIGO (McNemar's test p > 0.78) or across a range of performance parameters. This behaviour was maintained when applying algorithms simulating the logic of the nomograms. CONCLUSIONS: Our streamlined models could be used to assess GTN patients and replace FIGO, statistically matching performance. Given the importance of imaging parameters in guiding treatment, M2 and M3 are favoured for ongoing validation. In resource-poor countries, where access to specialist centres is problematic, M1 could be pragmatically implemented. Further prospective validation on a larger cohort is recommended.

Intra-individual comparison of prostate-specific membrane antigen positron emission tomography/computed tomography versus bone scan in detecting skeletal metastasis at prostate cancer diagnosis.

OBJECTIVES: To compare the diagnostic performance and radiological staging impact of 68 Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) compared to 99 Tc whole-body bone scan (WBBS) for the detection of skeletal metastasis in the primary staging of prostate cancer (PCa). PATIENTS AND METHODS: A prospective institutional database was retrospectively examined for patients who underwent both PSMA PET and WBBS within a 1 week interval for PCa primary staging. Lesions were categorised as 'negative', 'equivocal', or 'definite' based on nuclear medicine physician interpretation. Metastatic burden was characterised for each imaging modality according to three groups: (i) local disease (no skeletal metastases), (ii) oligometastatic disease (three or fewer skeletal metastases), or (iii) polymetastatic disease (more than three skeletal metastases). RESULTS: There were 667 patients included. The median (interquartile range) prostate-specific antigen level was 9.2 (6.2-16) ng/mL and 60% of patients were high risk according to a modified D'Amico risk classification. The overall distribution of skeletal metastasis detection changed across the two scans overall (P = 0.003), being maintained within high-risk (P = 0.030) and low-risk (P = 0.018) groups. PSMA PET/CT identified more definite skeletal metastases compared to WBBS overall (10.3% vs 7.3%), and according to risk grouping (high: 12% vs 9%, intermediate: 4% vs 1%). Upstaging was more common with PSMA PET/CT than WBBS (P = 0.001). The maximum standardised uptake value (SUVmax ) of the primary tumour was associated with upstaging of skeletal metastases on PSMA PET/CT (P = 0.025), while age was associated with upstaging on WBBS (P = 0.021). The SUVmax of the primary tumour and metastases were both higher according to extent of metastatic disease (P = 0.001 and P < 0.001, respectively). CONCLUSIONS: More skeletal metastases were detected with PSMA PET/CT than WBBS, resulting in a higher upstaging rate mostly in high-risk patients. The SUVmax of the primary tumour and metastases was associated with upstaging.

Barriers and enablers of active surveillance for prostate cancer: a qualitive study of clinicians.

OBJECTIVES: To identify and explore barriers to, and enablers of, active surveillance (AS) in men with low-risk prostate cancer (LRPCa), as perceived by PCa clinicians. PATIENTS AND METHODS: Urologists and radiation oncologists in Australia and New Zealand were purposively sampled for a cross-section on gender and practice setting (metropolitan/regional; public/private). Using a grounded theory approach, semi-structed interviews were conducted with participants. Interviews were coded independently by two researchers using open, axial, and selective coding. A constant comparative approach was used to analyse data as it was collected. Thematic saturation was reached after 18 interviews, and a detailed model of barriers to, and enablers of, AS for LRPCa, as perceived by clinicians was developed. RESULTS: A model explaining what affects clinician decision making regarding AS in LRPCa emerged. It was underpinned by three broad themes: (i) clinician perception of patients' barriers and enablers; (ii) clinician perception of their own barriers and enablers; and (iii) engagement with healthcare team and resource availability. CONCLUSIONS: Clinicians unanimously agree that AS is an evidence-based approach for managing LRPCa. Despite this many men do not undergo AS for LRPCa, which is due to the interplay of patient and clinician factors, and their interaction with the wider healthcare system. This study identifies strategies to mitigate barriers and enhance enablers, which could increase access to AS by patients with LRPCa.

High HIV prevalence in gestational trophoblastic neoplasia patients.

OBJECTIVE: To assess the HIV prevalence in patients diagnosed with gestational trophoblastic neoplasia (GTN). DESIGN: A retrospective single centre cohort study. METHODS: A database from the Sheffield Trophoblastic Disease Centre (STDC), Sheffield, UK was searched between 1st January 2015 and 31st December 2021. A total of 3,591 patients were referred to STDC with a diagnosis of gestational trophoblastic disease (GTD), of which 221 (6.2%) were treated for GTN. The prevalence of HIV-positive tests in GTN patients was assessed. RESULTS: HIV testing was performed in 93% GTN patients ( n  = 205/221). Overall, 1.3% of GTN patients ( n  = 3/221) were HIV-positive, involving two known HIV-positive patients and one new diagnosis. This equates to a HIV prevalence of 14 : 1000, which is ∼7 to 9× higher than the HIV prevalence in Sheffield (1.9 per 1000) and Yorkshire and Humber (1.5 per 1000). CONCLUSION: Given the extremely high HIV prevalence in our population, 'opt out' HIV testing is recommended within our specialist trophoblastic centre for all referred GTD and GTN patients. There is little reason to suspect that the prevalence of HIV-positive patients is any lower in the cohort of GTD patients referred to specialist trophoblastic centres for hCG screening alone, without requiring chemotherapy, particularly considering that most GTN arises from GTD.

Zinc oxide nanoparticles disrupt development and function of the olfactory sensory system impairing olfaction-mediated behaviour in zebrafish.

Zinc (Zn) is an essential metal present in numerous enzymes throughout the body, playing a vital role in animal and human health. However, the increasing use of zinc oxide nanomaterials (ZnONPs) in a diverse range of products has raised concerns regarding their potential impacts on health and the environment. Despite these concerns, the toxicity of ZnONP exposure on animal health remain poorly understood. To help address this knowledge gap, we have developed a highly sensitive oxidative stress (OS) biosensor zebrafish capable of detecting cell/tissue-specific OS responses to low doses of various oxidative stressors, including Zn, in a live fish embryo. Using live-imaging analysis with this biosensor zebrafish embryo, we discovered that the olfactory sensory neurons in the brain are especially sensitive to ZnOP exposure. Furthermore, through studies monitoring neutrophil migration and neuronal activation in the embryonic brain and via behaviour analysis, we have found that sub-lethal doses of ZnONPs (ranging from 0.033 to 1 mg/L nominal concentrations), which had no visible effect on embryo growth or morphology, cause significant localised inflammation, disrupting the neurophysiology of olfactory brain tissues and ultimately impaired olfaction-mediated behaviour. Collectively, these findings establish a potent and important effect mechanism for ZnONP toxicity, indicating the olfactory sensory system as the primary target for ZnONPs as an environmental toxicant in aquatic environments. Our result also highlights that even low doses of ZnONPs can have detrimental effects on the olfactory sensory system, surpassing previous expectations. The importance of olfaction in environment sensing, sex behaviours and overall fitness across species raises concerns about the potential impact of ZnONPs on olfaction-mediated brain function and behaviour in animals and humans. Our study emphasises the need for greater consideration of the potential risks associated with these nanomaterials.

Olaparib and Ceralasertib (AZD6738) in Patients with Triple-Negative Advanced Breast Cancer: Results from Cohort E of the plasmaMATCH Trial (CRUK/15/010).

PURPOSE: Approximately 10% to 15% of triple-negative breast cancers (TNBC) have deleterious mutations in BRCA1 and BRCA2 and may benefit from PARP inhibitor treatment. PARP inhibitors may also increase exogenous replication stress and thereby increase sensitivity to inhibitors of ataxia telangiectasia and Rad3-related (ATR) protein. This phase II study examined the activity of the combination of PARP inhibitor, olaparib, and ATR inhibitor, ceralasertib (AZD6738), in patients with advanced TNBC. PATIENTS AND METHODS: Patients with TNBC on most recent biopsy who had received 1 or 2 lines of chemotherapy for advanced disease or had relapsed within 12 months of (neo)adjuvant chemotherapy were eligible. Treatment was olaparib 300 mg twice a day continuously and celarasertib 160 mg on days 1-7 on a 28-day cycle until disease progression. The primary endpoint was confirmed objective response rate (ORR). Tissue and plasma biomarker analyses were preplanned to identify predictors of response. RESULTS: 70 evaluable patients were enrolled. Germline BRCA1/2 mutations were present in 10 (14%) patients and 3 (4%) patients had somatic BRCA mutations. The confirmed ORR was 12/70; 17.1% (95% confidence interval, 10.4-25.5). Responses were observed in patients without germline or somatic BRCA1/2 mutations, including patients with mutations in other homologous recombination repair genes and tumors with functional homologous recombination deficiency by RAD51 foci. CONCLUSIONS: The response rate to olaparib and ceralasertib did not meet prespecified criteria for activity in the overall evaluable population, but responses were observed in patients who would not be expected to respond to olaparib monotherapy.

Efficacy analysis of single-agent carboplatin AUC4 2-weekly as second-line therapy for methotrexate-resistant (MTX-R) low risk gestational trophoblastic neoplasia (GTN).

BACKGROUND: Approximately one-third of patients with low-risk Gestational Trophoblastic Neoplasia (WHO 0-6) develop methotrexate-resistance (MTX-R). In the UK, subsequent treatment with either actinomycin-D (ActD) or multi-agent combination chemotherapy has depended on whether the hCG was above or below an hCG threshold. To reduce exposure to combination chemotherapy (CC), over the years the UK service has raised this threshold as well as using single-agent carboplatin AUC6 3-weekly at MTX-R instead of CC. Updated results for carboplatin demonstrate an 86% complete hCG response (hCG CR) but associated with haematological dose-limiting toxicity. METHODS: In 2017, single-agent carboplatin became the national standard second-line treatment following MTX-R at hCG of >3000 IU/L. Carboplatin was changed to two-weekly AUC4 scheduling and continued until normal hCG plus 3 consolidation cycles. For patients failing to respond, CC (Etoposide-Actinomycin-D or EMA-CO) was introduced. RESULTS: 22 evaluable patients with a median hCG at MTX-R of 10,147 IU/L (IQR 5527-19,639) received carboplatin AUC4 2-weekly (median no. of cycles = 6, IQR 2-8). Of these, 36% achieved a hCG CR. All 14 non-CR patients were cured with subsequent CC; 11 and 2 patients with 3rd line and 4th line CC respectively and 1 patient following 5th line CC and hysterectomy. Overall survival remains 100%. CONCLUSION: Carboplatin is not sufficiently active in the second-line treatment of low-risk MTX-resistant GTN. New strategies are required to increase hCG CR and spare more toxic CC regimens.

The influence of size and surface chemistry on the bioavailability, tissue distribution and toxicity of gold nanoparticles in zebrafish (Danio rerio).

Gold nanoparticles (AuNPs) are widely used in biomedicine and their specific properties including, size, geometrics, and surface coating, will affect their fate and behaviour in biological systems. These properties are well studied for their intended biological targets, but there is a lack of understanding on the mechanisms by which AuNPs interact in non-target organisms when they enter the environment. We investigated the effects of size and surface chemistry of AuNPs on their bioavailability, tissue distribution and potential toxicity using zebrafish (Danio rerio) as an experimental model. Larval zebrafish were exposed to fluorescently tagged AuNPs of different sizes (10-100 nm) and surface modifications (TNFα, NHS/PAMAM and PEG), and uptake, tissue distribution and depuration rates were measured using selective-plane illumination microscopy (SPIM). The gut and pronephric tubules were found to contain detectable levels of AuNPs, and the concentration-dependent accumulation was related to the particle size. Surface addition of PEG and TNFα appeared to enhance particle accumulation in the pronephric tubules compared to uncoated particles. Depuration studies showed a gradual removal of particles from the gut and pronephric tubules, although fluorescence indicating the presence of the AuNPs remained in the pronephros 96 h after exposure. Toxicity assessment using two transgenic zebrafish reporter lines, however, revealed no AuNP-related renal injury or cellular oxidative stress. Collectively, our data show that AuNPs used in medical applications across the size range 40-80 nm, are bioavailable to larval zebrafish and some may persist in renal tissue, although their presence did not result in measurable toxicity with respect to pronephric organ function or cellular oxidative stress for short term exposures.

How to do an open midline extraperitoneal bilateral retroperitoneal lymph node dissection for non-seminomatous germ cell tumour.

Retroperitoneal lymph node dissection, remains a crucial step in the management of patients with non-seminomatous germ cell tumours who have undergone chemotherapy. It is a technically challenging operation with a number of techniques that have been advocated. We outline the midline, extraperitoneal approach to perform a bilateral template lymph node dissection.

Modern Active Surveillance in Prostate Cancer: A Narrative Review.

The use of PSA screening has led to downstaging and downgrading of prostate cancer at diagnosis, increasing detection of indolent disease. Active surveillance aims to reduce over-treatment by delaying or avoiding radical treatment and its associated morbidity. However, there is not a consensus on the selection criteria and monitoring schedules that should be used. This article aims to summarize the evidence supporting the safety of active surveillance, the current selection criteria recommended and in use, the incidence of active surveillance, barriers existing to its uptake and future developments in patient selection.

Flat-dose versus weight or body surface area-based methotrexate dosing in low-risk gestational trophoblastic neoplasia.

BACKGROUND: Single-agent methotrexate (MTX) is commonly used as first-line treatment for low-risk gestational trophoblastic neoplasia (LR-GTN), although no international consensus exists on the optimal treatment regimen to maximise complete hCG response (CR) and minimise relapse rates. Current regimens differ in the route of administration, dose scheduling, and use of flat-dose, body surface area (BSA)- or weight-based dosing. In the UK a methotrexate-folinic acid (MTX-FA) 8-day 50 mg intramuscular flat-dose regimen is used, with 15 mg oral folinic acid rescue. In LR-GTN patients, we aim to determine the effect of MTX dose adjustment by BSA and weight upon chemotherapy response and disease relapse. METHODS: Between January 1973 and August 2020, 935 LR-GTN patients treated with first-line MTX-FA were identified from a single UK specialist trophoblastic centre. Of these, 364 were included, of which 178 (49%) had a CR to first-line MTX-FA. Subgroup analyses were performed upon: (i) patients who changed chemotherapy due to MTX toxicity (n = 33); and (ii) patients with a FIGO score of 5-6 (n = 85). Logistic regression analysis explored the relationship between BSA or weight adjusted MTX dosing and: (i) CR to first-line chemotherapy; (ii) incidence of disease relapse. Linear regression analyses assessed the correlation of BSA and weight with the number of MTX-FA cycles required to achieve CR. RESULTS: In LR-GTN patients, BSA and weight adjusted MTX-FA dosing did not influence CR to first-line chemotherapy or the incidence of disease relapse. The number of MTX cycles required to achieve CR was not associated with BSA or weight. These findings were maintained in a subgroup analysis of FIGO 5-6 patients. The incidence of MTX toxicity was not influenced by BSA or weight. CONCLUSIONS: In the treatment of LR-GTN, dose individualisation using BSA or weight is not required, and fixed dosing continues to be preferred as the UK standard.

PREDICT-GTN 1: Can we improve the FIGO scoring system in gestational trophoblastic neoplasia?

Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.

Self-Efficacy and Student Satisfaction in a Clinical-Year Diagnostic Imaging Course Using an Online Instruction Format.

Accurate interpretation of radiographic images is critical to diagnosing clinical patients. Remote instruction in radiology has become more common at veterinary colleges as academic institutions struggle to fill open veterinary radiologist positions and as a result of the COVID-19 pandemic. This study sought to gather the feedback of fourth-year veterinary students via pre- and post-study surveys (n = 45) and focus groups (n = 7) about a newly implemented 2-week long radiology rotation. Ninety-eight percent of students reported having taken an online course before, and on both pre- and post-study surveys, students commonly reported feeling interested, determined, and attentive. On average, students reported that they were neither more nor less engaged than they would have been in an in-person course and that they understood the material neither better nor worse than they would have in an in-person course. Students reported that the key to their success was primarily hard work; secondarily, instructor availability and student ability were important. Students did not rate luck as having much influence on their success. Although diagnostic imaging can be a challenging subject to master, students effectively learned this subject through online instruction. They provided feedback for the course's continued improvement; their comments centered around improved interactivity, including providing automated quiz questions' answers and increased instructor availability. Data collected in this study will help to guide further development of the radiology course.

Midline extraperitoneal approach to retroperitoneal pathology - broadening the horizons.

We present an explanation of approach to open midline extraperitoneal surgery for the management of retroperitoneal pathology. Included are diagrammatic and intra-operative images to better explain the approach, as well as discussion regarding the technique.

A phase IB and randomised phase IIA trial of CApecitabine plus Radium-223 (Xofigo™) in breast cancer patients with BONe metastases: CARBON trial results.

Background: Approximately 70% of patients with metastatic breast cancer (MBC) develop bone metastases. Despite advances in systemic treatment options and the use of bone targeted agents in the management of bone metastases to reduce skeletal morbidity, there remains an unmet need for further treatment options. Radium-223 (Ra223) is an alpha-emitting radiopharmaceutical that is preferentially taken up into bone at sites of increased osteoblastic activity where it emits high-energy, short-range alpha-particles that could provide a targeted anti-tumour effect on bone metastases. Here we evaluate the safety, feasibility and efficacy findings of the combination of Ra223 with capecitabine chemotherapy in patients with MBC with bone involvement. Methods: CARBON is a multi-centre, open-label phase IB/IIA study evaluating the combination of Ra223 (55 kBq/kg day 1 given on 6 weekly schedule) and capecitabine (1000 mg/m2 bd days 4-17 every 21 days) in patients with bone metastases from MBC (± other disease sites). Other eligibility criteria included ECOG performance status 0-2, ≤2 lines of chemotherapy for MBC and current bisphosphonate or denosumab use for ≥ 6 weeks. The phase IB part of the trial (6 patients) was conducted to provide preliminary feasibility and safety of capecitabine + Ra223. Thereafter, 28 patients were randomised (2:1) to capecitabine + Ra223 or capecitabine alone to further characterise the safety profile and evaluate efficacy, the primary efficacy endpoint being the bone turnover marker (urinary n-telopeptide of type I collagen) change from baseline to end of cycle 5 and secondary endpoints of time to first symptomatic skeletal event, and disease progression at extra-skeletal and bone disease. Results: In addition to bone metastases, 10/23 [44%] and 13/23 [57%] capecitabine + Ra223 and 2/11 [18%] and 9/11 [82%] capecitabine alone patients had soft tissue and visceral disease sites respectively. More capecitabine + Ra223 patients had received prior chemotherapy for MBC: 11/23 [48%] vs 2/11 [18%]. The analysis populations comprise 34 patients (23 capecitabine + Ra223, 11 capecitabine); 2 patients randomised to capecitabine + Ra223 received capecitabine alone and are included in the capecitabine arm. Median number of cycles received was 8.5 in capecitabine + Ra223 (range 3-12) and 12 in the capecitabine arm (range 1-12). 94/95 prescribed Ra223 cycles were administered. No dose limiting toxicities were seen in phase IB and no patients developed grade ≥ III diarrhoea. Gastrointestinal, haematological and palmer-planter erthyrodysesthesia adverse events were similar in both arms. Although formal statistical comparisons were not made, changes in bone turnover markers, the times to extra-skeletal progression and bone disease progression, and the frequency of symptomatic skeletal events were similar across the two treatment arms. Conclusion: Capecitabine + Ra223 at the planned dose was safe and feasible in MBC patients with bone metastases. However, no efficacy signals were seen that might suggest greater efficacy of the combination over capecitabine alone clinically or biochemically.

A Combined Human in Silico and CRISPR/Cas9-Mediated in Vivo Zebrafish Based Approach to Provide Phenotypic Data for Supporting Early Target Validation.

The clinical heterogeneity of heart failure has challenged our understanding of the underlying genetic mechanisms of this disease. In this respect, large-scale patient DNA sequencing studies have become an invaluable strategy for identifying potential genetic contributing factors. The complex aetiology of heart failure, however, also means that in vivo models are vital to understand the links between genetic perturbations and functional impacts as part of the process for validating potential new drug targets. Traditional approaches (e.g., genetically-modified mice) are optimal for assessing small numbers of genes, but less practical when multiple genes are identified. The zebrafish, in contrast, offers great potential for higher throughput in vivo gene functional assessment to aid target prioritisation, by providing more confidence in target relevance and facilitating gene selection for definitive loss of function studies undertaken in mice. Here we used whole-exome sequencing and bioinformatics on human patient data to identify 3 genes (API5, HSPB7, and LMO2) suggestively associated with heart failure that were also predicted to play a broader role in disease aetiology. The role of these genes in cardiovascular system development and function was then further investigated using in vivo CRISPR/Cas9-mediated gene mutation analysis in zebrafish. We observed multiple impacts in F0 knockout zebrafish embryos (crispants) following effective somatic mutation, including changes in ventricle size, pericardial oedema, and chamber malformation. In the case of lmo2, there was also a significant impact on cardiovascular function as well as an expected reduction in erythropoiesis. The data generated from both the human in silico and zebrafish in vivo assessments undertaken supports further investigation of the potential roles of API5, HSPB7, and LMO2 in human cardiovascular disease. The data presented also supports the use of human in silico genetic variant analysis, in combination with zebrafish crispant phenotyping, as a powerful approach for assessing gene function as part of an integrated multi-level drug target validation strategy.