Evaluating Systemic Burnout in Medical Oncology Through a National Oncology Mentorship Program.

PURPOSE: Mentorship has a positive influence on trainee skills and well-being. A 2022 Pilot Mentorship Program in New South Wales involving 40 participants revealed high burnout rates in Medical Oncology trainees. As part of an Australia-wide inaugural National Oncology Mentorship Program in 2023 (NOMP23), a national survey was undertaken to assess the prevalence of burnout, anxiety, depression, professional fulfilment, and drivers of distress in the Australian medical oncology workforce. METHODS: NOMP23 is a 1-year prospective cohort study that recruited medical oncology trainees and consultants using e-mail correspondence between February and March 2023. Each participant completed a baseline survey which included the Maslach Burnout Index (MBI), Stanford Professional Fulfilment Index, and Patient Health Questionnaire-4 for anxiety and depression. RESULTS: One hundred and twelve participants (56 mentors, 56 mentees) were enrolled in NOMP23, of which 86 (77%) completed the baseline survey. MBI results at baseline demonstrated that 77% of consultants and 82% of trainees experienced burnout in the past 12 months. Professional fulfilment was noted to be <5% in our cohort. Screening rates of anxiety and depression in trainees were 32% and 16%, respectively, compared with 7% and 2% for consultants. When assessing reasons for workplace stress, two thirds stated that heavy patient load contributed to stress, while almost three quarters attributed a heavy administrative load. Lack of supervision was a key stressor for trainees (39%), as was lack of support from the training college (58%). CONCLUSION: Trainees and consultant medical oncologists demonstrate high rates of burnout and low professional fulfilment. The NOMP23 program has identified a number of key stress factors driving burnout and demonstrated concerning levels of anxiety and depression. Ongoing mentorship and other well-being initiatives are needed to address these issues.

p21 as a Predictor and Prognostic Indicator of Clinical Outcome in Rectal Cancer Patients.

The cell cycle plays a key and complex role in the development of human cancers. p21 is a potent cyclin-dependent kinase inhibitor (CDKI) involved in the promotion of cell cycle arrest and the regulation of cellular senescence. Altered p21 expression in rectal cancer cells may affect tumor cells' behavior and resistance to neoadjuvant and adjuvant therapy. Our study aimed to ascertain the relationship between the differential expression of p21 in rectal cancer and patient survival outcomes. Using tissue microarrays, 266 rectal cancer specimens were immunohistochemically stained for p21. The expression patterns were scored separately in cancer cells retrieved from the center and the periphery of the tumor; compared with clinicopathological data, tumor regression grade (TRG), disease-free, and overall survival. Negative p21 expression in tumor periphery cells was significantly associated with longer overall survival upon the univariate (p = 0.001) and multivariable analysis (p = 0.003, HR = 2.068). Negative p21 expression in tumor periphery cells was also associated with longer disease-free survival in the multivariable analysis (p = 0.040, HR = 1.769). Longer overall survival times also correlated with lower tumor grades (p= 0.011), the absence of vascular and perineural invasion (p = 0.001; p < 0.005), the absence of metastases (p < 0.005), and adjuvant treatment (p = 0.009). p21 expression is a potential predictive and prognostic biomarker for clinical outcomes in rectal cancer patients. Negative p21 expression in tumor periphery cells demonstrated significant association with longer overall survival and disease-free survival. Larger prospective studies are warranted to investigate the ability of p21 to identify rectal cancer patients who will benefit from neoadjuvant and adjuvant therapy.

Real-world tolerance and outcomes of oxaliplatin-based adjuvant chemotherapy for stage III colon cancer-Does dose intensity matter?

INTRODUCTION: Fluoropyrimidine and oxaliplatin-based adjuvant chemotherapy delivered as 5-fluorouracil, leucovorin and oxaliplatin (FOLFOX), or capecitabine and oxaliplatin (CAPOX) is the standard of care for resected stage III colon cancer. Without randomized trial data, we compared real-world dose intensity, survival outcomes, and tolerability of these regimens. METHODS: Records of patients treated with FOLFOX or CAPOX in the adjuvant setting for stage III colon cancer across four institutions in Sydney during 2006-2016 were reviewed. The relative dose intensity (RDI) of fluoropyrimidine and oxaliplatin of each regimen, disease-free survival (DFS), overall survival (OS), and incidence of grade ≥2 toxicities were compared. RESULTS: Characteristics of patients receiving FOLFOX (n = 195) and CAPOX (n = 62) were evenly matched. FOLFOX patients had a higher mean RDI for both fluoropyrimidine (85% vs. 78%, p < 0.01) and oxaliplatin (72% vs. 66%, p = 0.06). In spite of a lower RDI, CAPOX patients trended toward a better 5-year DFS (84% vs. 78%, HR = 0.53, p = 0.068) and similar OS (89% vs. 89%, HR = 0.53, p = 0.21) compared to the FOLFOX group. This difference was most pronounced in the high-risk (T4 or N2) group where 5-year DFS was 78% versus 67% (HR = 0.41, p = 0.042). Patients receiving CAPOX experienced more grade ≥2 diarrhea (p = 0.017) and hand-foot syndrome (p < 0.001) but not peripheral neuropathy or myelosuppression. CONCLUSION: In a real-world setting, patients who received CAPOX had similar OS rates when compared to those receiving FOLFOX in the adjuvant setting in spite of lower RDI. In the high-risk population, CAPOX appears to demonstrate a superior 5-year DFS over FOLFOX.

Utility of multigene panel next-generation sequencing in routine clinical practice for identifying genomic alterations in newly diagnosed metastatic nonsmall cell lung cancer.

BACKGROUND: The standard of care in newly diagnosed metastatic non-small cell lung cancer (NSCLC) is to test for aberrations in three genes for driver mutations - ALK, ROS1 and epidermal growth factor receptor (EGFR) - and also for immunohistochemistry to be performed for programmed death-ligand 1 expression level. Next-generation sequencing (NGS), with or without RNA fusion testing, is increasingly used in standard clinical practice to identify patients with potentially actionable mutations. Stratification of NGS mutation tiers is currently based on the European Society of Medical Oncology Scale for Clinical Actionability of Molecular Targets (ESCAT) Tiers I-V and X. AIM: Our aim was to analyse NSCLC tumour samples for the prevalence of Tiers I-V mutations to establish guidance for current and novel treatments in patients with metastatic disease. METHODS: NGS was performed employing the Oncomine Precision Assay (without RNA fusion testing) that interrogates DNA hotspot variants across 45 genes to screen 210 NSCLC tissue samples obtained across six Sydney hospitals between June 2021 and March 2022. RESULTS: In our cohort, 161 of 210 (77%) had at least one gene mutation identified, with 41 of 210 (20%) having two or more concurrent mutations. Tier I mutations included 42 of 210 (20%) EGFR mutations (EIA) and five of 210 (3%) MET exon 14 skipping mutations (EIB). Non-Tier I variants included 22 of 210 (11%) KRAS G12C hotspot mutations (EIIB), with a further 47 of 210 (22%) having non-G12C KRAS (EX) mutations. NGS testing revealed an additional 15% of cases with Tier II ESCAT mutations in NSCLC. Forty-six percent of patients also demonstrated potential Tier III and IV mutations that are currently under investigation in early-phase clinical trials. CONCLUSIONS: In addition to identifying patients with genomic alterations suitable for clinically proven standard-of-care therapeutic options, the 45-gene NGS panel has significant potential in identifying potentially actionable non-Tier 1 mutations that may become future standard clinical practice in NSCLC.

KRAS and BRAF Mutation Rates and Survival Outcomes in Colorectal Cancer in an Ethnically Diverse Patient Cohort.

KRAS and BRAF mutation rates in colorectal cancer (CRC) reported from various mono-ethnic studies vary amongst different ethnic groups. However, these differences in mutation rates may not be statistically significant or may be due to differences in environmental and/or laboratory factors across countries rather than racial genetic differences. Here, we compare the KRAS/BRAF mutation rates and survival outcomes in CRC between ethnic groups at a single institution. We also investigate the contributions of genetic, environmental, and laboratory factors to the variations in KRAS/BRAF mutation rates reported from different countries. Clinicopathological data from 453 ethnically diverse patients with CRC were retrospectively analyzed at Liverpool Hospital, NSW Australia (2014-2016). KRAS/BRAF mutations were detected using real-time PCR (Therascreen kits from Qiagen). Mismatch repair (MMR) status was determined using immunohistochemical staining. Four ethnic groups were analyzed: Caucasian, Middle Eastern, Asian, and South American. Overall survival data were available for 406 patients. There was no significant difference in KRAS mutation rates between Caucasians (41.1%), Middle Easterners (47.9%), Asians (44.8%), and South Americans (25%) (p = 0.34). BRAF mutation rates differed significantly between races (p = 0.025), with Caucasians having the highest rates (13.5%) and Middle Easterners the lowest (0%). A secondary analysis in which Caucasians were divided into three subgroups showed that ethnic grouping correlated significantly with KRAS mutation rate (p = 0.009), with central and eastern Europeans having the highest rates (58.3%). There were no significant differences in overall survival (OS) or disease-free survival (DFS) between the four races. The similarity in KRAS mutation rates across races raises the possibility that the differences in KRAS mutation rates reported from various countries may either not be statistically significant or may be due to environmental and/or laboratory factors rather than underlying racial genetic differences. In contrast, we verified that BRAF mutation rates differ significantly between races, suggesting racial genetic differences may be responsible for the discrepant BRAF mutation rates reported from different countries.

Real-World Outcomes of FLOT versus CROSS Regimens for Patients with Oesophagogastric Cancers.

Introduction: Treatment of oesophageal (OC), gastro-oesophageal junction (GOJ), and gastric cancer (GC) includes either neoadjuvant Chemoradiotherapy for Oesophageal Cancer Followed by Surgery Study (CROSS) for OC or GOJ or perioperative 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel (FLOT) for OC, GOJ, and GC adenocarcinomas. This study aims to describe the real-world outcomes of patients with GC, GOJ, and OC treated with FLOT or CROSS and identify variables associated with efficacy through exploratory analysis. We also aimed to evaluate the comparison of FLOT and CROSS for the treatment of OC and GOJ adenocarcinomas. Methods: This is a retrospective observational study of patients with locally advanced OC, GOJ, or GC treated with FLOT or CROSS between January 2015 and June 2021 in 5 cancer centres across Sydney, Australia. Long-rank test was used to compare survival estimated between subgroups. Hazard ratios for univariate and multivariate analyses were estimated with Cox proportional regression. Results: The study included 168 patients. The 24-month relapse-free survival (RFS) and overall survival (OS) for FLOT were 59% and 69%, respectively. The median RFS was 29.6 months and median OS was not reached. For CROSS, the 24-month RFS and OS were 55% and 63% with a median RFS and OS of 28.5 and 40.2 months, respectively. There was no difference in OS and RFS between the treatments. FLOT was less tolerable than CROSS with more dose reductions, treatment discontinuation, and clinically relevant grade 3 and 4 toxicity. Neutrophil lymphocyte ratio was associated with survival for both treatments. Conclusion: Similar efficacy outcomes were seen in this real-world population compared to the clinical trials for FLOT and CROSS.

Multigene panel next generation sequencing in metastatic colorectal cancer in an Australian population.

BACKGROUND: Next generation sequencing (NGS) is increasingly used in standard clinical practice to identify patients with potentially actionable mutations. Stratification of NGS mutation tiers is currently based on the European Society of Medical Oncology (ESMO) Scale for Clinical Actionability of Molecular Targets (ESCAT[E]) Tier I-V & X. Allele frequency is also increasingly recognised as an important prognostic tool in advanced cancer. The aim of this study was to determine the genomic mutations in metastatic colorectal cancer (CRC) in an Australian multicultural population and their influence on survival outcomes. METHODS: Next generation sequencing with the 50-gene panel Oncomine Precision Assay™ was used on 180 CRC tissue samples obtained across six Sydney hospitals between June 2021 and March 2022. RESULTS: From 180 samples, 147 (82%) had at least one gene mutation identified with 68 (38%) having two or more concurrent mutations. Tier I variants included RAS wild-type [EI] in 73 (41%) and BRAF V600E [EIA] in 27 (15%). Non-tier I variants include 2 (1%) ERBB2 amplification [EIIB], 26 (15%) PIK3CA hotspot mutations [EIIIA] and 9 (5%) MET focal amplifications [EIIIA]. NGS testing revealed an additional 22% of cases with Tier II & III mutations. 43% of patients also presented with potentially actionable Tier III & IV mutations. Patients with concurrent TP53 and RAS mutations had significantly reduced overall survival (6.1 months versus 21.1 months, p <0.01). High KRAS allele frequency, as defined by those with over 20% variant allele frequency (VAF), also demonstrated reduced overall survival (12.1 months versus 42.9 months, p = 0.04). CONCLUSIONS: In addition to identifying patients with genomic alterations suitable for clinically proven standard of care therapeutic options, the 50 gene NGS panel has significant potential in identifying potentially actionable non-tier 1 mutations and therefore may become future standard clinical practice.

Circulating Tumour Cell Associated MicroRNA Profiles Change during Chemoradiation and Are Predictive of Response in Locally Advanced Rectal Cancer.

Locally advanced rectal cancer (LARC) has traditionally been treated with trimodality therapy consisting of neoadjuvant radiation +/- chemotherapy, surgery, and adjuvant chemotherapy. There is currently a clinical need for biomarkers to predict treatment response and outcomes, especially during neoadjuvant therapy. Liquid biopsies in the form of circulating tumour cells (CTCs) and circulating nucleic acids in particular microRNAs (miRNA) are novel, the latter also being highly stable and clinically relevant regulators of disease. We studied a prospective cohort of 52 patients with LARC, and obtained samples at baseline, during treatment, and post-treatment. We enumerated CTCs during chemoradiation at these three time-points, using the IsofluxTM (Fluxion Biosciences Inc., Alameda, CA, USA) CTC Isolation and detection platform. We then subjected the isolated CTCs to miRNA expression analyses, using a panel of 106 miRNA candidates. We identified CTCs in 73% of patients at baseline; numbers fell and miRNA expression profiles also changed during treatment. Between baseline and during treatment (week 3) time-points, three microRNAs (hsa-miR-95, hsa-miR-10a, and hsa-miR-16-1*) were highly differentially expressed. Importantly, hsa-miR-19b-3p and hsa-miR-483-5p were found to correlate with good response to treatment. The latter (hsa-miR-483-5p) was also found to be differentially expressed between good responders and poor responders. These miRNAs represent potential predictive biomarkers, and thus a potential miRNA-based treatment strategy. In this study, we demonstrate that CTCs are present and can be isolated in the non-metastatic early-stage cancer setting, and their associated miRNA profiles can potentially be utilized to predict treatment response.

Haematological and nutritional prognostic biomarkers for patients receiving CROSS or FLOT.

Background: Neoadjuvant carboplatin and paclitaxel with radiotherapy (CROSS) and perioperative docetaxel, oxaliplatin, calcium folinate and fluorouracil (FLOT) are widely used for gastric (GC), gastro-oesophageal junction (GOJ) and oesophageal cancers (OC). Prognostic and predictive markers for response and survival outcomes are lacking. This study evaluates dynamic neutrophil-lymphocyte ratios (NLR), platelet-lymphocyte ratios (PLR), albumin and body mass index (BMI) as predictors of survival, response and toxicity. Methods: This multi-centre retrospective observational study across 5 Sydney hospitals included patients receiving CROSS or FLOT from 2015 to 2021. Haematological results and BMI were recorded at baseline and pre-operatively, and after adjuvant treatment for FLOT. Toxicities were also recorded. An NLR ≥2 and PLR ≥200 was used to stratify patients. Univariate and multivariate analyses were performed to determine predictors of overall survival (OS), disease free survival (DFS), rates of pathological complete response (pCR) and toxicity. Results: One hundred sixty-eight patients were included (95 FLOT, 73 FLOT). A baseline NLR ≥2 was predictive for worse DFS (HR 2.78, 95% CI: 1.41-5.50, P<0.01) and OS (HR 2.90, 95% CI: 1.48-5.67, P<0.01). Sustained elevation in NLR was predictive for DFS (HR 1.54, 95% CI: 1.08-2.17, P=0.01) and OS (HR 1.65, 95% CI: 1.17-2.33, P<0.01). An NLR ≥2 correlated with worse pCR rates (16% for NLR ≥2, 48% for NLR <2, P=0.04). A baseline serum albumin <33 was predictive of worse DFS and OS with a HR of 6.17 (P=0.01) and 4.66 (P=0.01) respectively. Baseline PLR, BMI, and dynamic changes in these markers were not associated with DFS, OS or pCR rates. There was no association of the aforementioned variables with toxicity. Conclusions: This demonstrates that a high inflammatory state represented by an NLR ≥2, both at baseline and sustained, is prognostic and predictive of response in patients receiving FLOT or CROSS. Baseline hypoalbuminaemia is predictive of poorer outcomes.

Prognostic Significance of MRE11 Overexpression in Colorectal Cancer Patients.

Meiotic recombination 11 (MRE11) plays a critical role in the DNA damage response and maintenance of genome stability and is associated with the prognosis for numerous malignancies. Here, we explored the clinicopathological significance and prognostic value of MRE11 expression in colorectal cancer (CRC), a leading cause of cancer-related deaths worldwide. Samples from 408 patients who underwent surgery for colon and rectal cancer between 2006 and 2011, including a sub-cohort of 127 (31%) patients treated with adjuvant therapy, were analyzed. In Kaplan-Meier survival analyses, we found that high MRE11 expression in the tumor center (TC) was significantly associated with poor disease-free survival (DFS; p = 0.045) and overall survival (OS; p = 0.039). Intriguingly, high MRE11 expression in the TC was also significantly correlated with reduced DFS (p = 0.005) and OS (p = 0.010) in the subgroup with right-sided primary CRC. In multivariate analyses, high MRE11 expression (hazard ratio [HR] = 1.697, 95% confidence interval [CI]: 1.034-2.785; p = 0.036) and lymphovascular/perineural invasion (LVI/PNI; HR = 1.922, 95% CI 1.122-3.293; p = 0.017) showed significant association with worse OS in patients with right-sided tumors but not those with left-sided tumors. Moreover, in patients with right-sided tumors, high MRE11 was associated with worse OS for those with lymph node involvement (p = 0.006) and LVI/PNI (p = 0.049). Collectively, our results suggest that MRE11 may serve as an independent prognostic marker in those with right-sided severe CRC, with clinical value in the management of these patients.

A Functional Polymorphism Downstream of Vitamin A Regulator Gene CYP26B1 Is Associated with Hand Osteoarthritis.

While genetic analyses have revealed ~100 risk loci associated with osteoarthritis (OA), only eight have been linked to hand OA. Besides, these studies were performed in predominantly European and Caucasian ancestries. Here, we conducted a genome-wide association study in the Han Chinese population to identify genetic variations associated with the disease. We recruited a total of 1136 individuals (n = 420 hand OA-affected; n = 716 unaffected control subjects) of Han Chinese ancestry. We carried out genotyping using Axiom Asia Precisi on Medicine Research Array, and we employed the RegulomeDB database and RoadMap DNase I Hypersensitivity Sites annotations to further narrow down our potential candidate variants. Genetic variants identified were tested in the Geisinger's hand OA cohort selected from the Geisinger MyCode community health initiative (MyCode®). We also performed a luciferase reporter assay to confirm the potential impact of top candidate single-nucleotide polymorphisms (SNPs) on hand OA. We identified six associated SNPs (p-value = 6.76 × 10-7-7.31 × 10-6) clustered at 2p13.2 downstream of the CYP26B1 gene. The strongest association signal identified was rs883313 (p-value = 6.76 × 10-7, odds ratio (OR) = 1.76), followed by rs12713768 (p-value = 1.36 × 10-6, OR = 1.74), near or within the enhancer region closest to the CYP26B1 gene. Our findings showed that the major risk-conferring CC haplotype of SNPs rs12713768 and rs10208040 [strong linkage disequilibrium (LD); D' = 1, r2 = 0.651] drives 18.9% of enhancer expression activity. Our findings highlight that the SNP rs12713768 is associated with susceptibility to and severity of hand OA in the Han Chinese population and that the suggested retinoic acid signaling pathway may play an important role in its pathogenesis.

Structure of trimeric pre-fusion rabies virus glycoprotein in complex with two protective antibodies.

Rabies virus (RABV) causes lethal encephalitis and is responsible for approximately 60,000 deaths per year. As the sole virion-surface protein, the rabies virus glycoprotein (RABV-G) mediates host-cell entry. RABV-G's pre-fusion trimeric conformation displays epitopes bound by protective neutralizing antibodies that can be induced by vaccination or passively administered for post-exposure prophylaxis. We report a 2.8-Å structure of a RABV-G trimer in the pre-fusion conformation, in complex with two neutralizing and protective monoclonal antibodies, 17C7 and 1112-1, that recognize distinct epitopes. One of these antibodies is a licensed prophylactic (17C7, Rabishield), which we show locks the protein in pre-fusion conformation. Targeted mutations can similarly stabilize RABV-G in the pre-fusion conformation, a key step toward structure-guided vaccine design. These data reveal the higher-order architecture of a key therapeutic target and the structural basis of neutralization by antibodies binding two key antigenic sites, and this will facilitate the development of improved vaccines and prophylactic antibodies.

Homologous or heterogenous vaccination boosters enhance neutralizing activities against SARS-CoV-2 Omicron BA.1 variant.

The SARS-CoV-2 Omicron BA.1 variant of concern contains more than 30 mutations in the spike protein, with half of these mutations localized in the receptor-binding domain (RBD). Emerging evidence suggests that these large number of mutations impact the neutralizing efficacy of vaccines and monoclonal antibodies. We investigated the relative contributions of spike protein and RBD mutations in Omicron BA.1 variants on infectivity, cell-cell fusion, and their sensitivity to neutralization by monoclonal antibodies or vaccinated sera from individuals who received homologous (CoronaVac, SinoPharm) or heterologous (CoronaVac-BNT162b2, BioNTech) and nonhuman primates that received a recombinant RBD protein vaccine. Our data overall reveal that the mutations in the spike protein reduced infectivity and cell-cell fusion compared to the D614G variant. The impaired infectivity and cell-cell fusion were dependent on non-RBD mutations. We also find reduced sensitivity to neutralization by monoclonal antibodies and vaccinated sera. However, our results also show that nonhuman primates receiving a recombinant RBD protein vaccine show substantial neutralization activity. Our study sheds light on the molecular differences in neutralizing antibody escape by the Omicron BA.1 variant, and highlights the promise of recombinant RBD vaccines in neutralizing the threat posed by the Omicron BA.1 variant.

dCas9 fusion to computer-designed PRC2 inhibitor reveals functional TATA box in distal promoter region.

Bifurcation of cellular fates, a critical process in development, requires histone 3 lysine 27 methylation (H3K27me3) marks propagated by the polycomb repressive complex 2 (PRC2). However, precise chromatin loci of functional H3K27me3 marks are not yet known. Here, we identify critical PRC2 functional sites at high resolution. We fused a computationally designed protein, EED binder (EB), which competes with EZH2 and thereby inhibits PRC2 function, to dCas9 (EBdCas9) to allow for PRC2 inhibition at a precise locus using gRNA. Targeting EBdCas9 to four different genes (TBX18, p16, CDX2, and GATA3) results in precise H3K27me3 and EZH2 reduction, gene activation, and functional outcomes in the cell cycle (p16) or trophoblast transdifferentiation (CDX2 and GATA3). In the case of TBX18, we identify a PRC2-controlled, functional TATA box >500 bp upstream of the TBX18 transcription start site (TSS) using EBdCas9. Deletion of this TATA box eliminates EBdCas9-dependent TATA binding protein (TBP) recruitment and transcriptional activation. EBdCas9 technology may provide a broadly applicable tool for epigenomic control of gene regulation.

Contrasting Modes of New World Arenavirus Neutralization by Immunization-Elicited Monoclonal Antibodies.

Transmission of the New World hemorrhagic fever arenaviruses Junín virus (JUNV) and Machupo virus (MACV) to humans is facilitated, in part, by the interaction between the arenavirus GP1 glycoprotein and the human transferrin receptor 1 (hTfR1). We utilize a mouse model of live-attenuated immunization with envelope exchange viruses to isolate neutralizing monoclonal antibodies (NAbs) specific to JUNV GP1 and MACV GP1. Structures of two NAbs, termed JUN1 and MAC1, demonstrate that they neutralize through disruption of hTfR1 recognition. JUN1 utilizes a binding mode common to all characterized infection- and vaccine-elicited JUNV-specific NAbs, which involves mimicking hTfR1 binding through the insertion of a tyrosine into the receptor-binding site. In contrast, MAC1 undergoes a tyrosine-mediated mode of antigen recognition distinct from that used by the reported anti-JUNV NAbs and the only other characterized anti-MACV NAb. These data reveal the varied modes of GP1-specific recognition among New World arenaviruses by the antibody-mediated immune response. IMPORTANCE The GP1 subcomponent of the New World arenavirus GP is a primary target of the neutralizing antibody response, which has been shown to be effective in the prevention and treatment of infection. Here, we characterize the structural basis of the antibody-mediated immune response that arises from immunization of mice against Junín virus and Machupo virus, two rodent-borne zoonotic New World arenaviruses. We isolate a panel of GP1-specific monoclonal antibodies that recognize overlapping epitopes and exhibit neutralizing behavior, in vitro. Structural characterization of two of these antibodies indicates that antibody recognition likely interferes with GP1-mediated recognition of the transferrin receptor 1. These data provide molecular-level detail for a key region of vulnerability on the New World arenavirus surface and a blueprint for therapeutic antibody development.

Peripheral Cytokine Levels as a Prognostic Indicator in Gastric Cancer: A Review of Existing Literature.

Although strong connections exist between the carcinogenesis of gastric cancer and chronic inflammation, gastric cancer is unique in that the chronic gastritis which frequently precedes carcinogenesis is strongly associated with H. pylori infection. The interplay between H. pylori virulence factors and host immune cells is complex but culminates in the activation of inflammatory pathways and transcription factors such as NF-κB, STAT3, and AP-1, all of which upregulate cytokine production. Due to the key role of cytokines in modulating the immune response against tumour cells as well as possibly stimulating tumour growth and proliferation, different patterns of cytokine secretion may be associated with varying patient outcomes. In relation to gastric cancer, interleukin-6, 8, 10, 17A, TNF, and IFN-γ may have pro-tumour properties, although interleukin-10, TNF, and IFN-γ may have anti-tumour effects. However, due to the lack of studies investigating patient outcomes, only a link between higher interleukin-6 levels and poorer prognosis has been demonstrated. Further investigations which link peripheral cytokine levels to patient prognosis may elucidate important pathological mechanisms in gastric cancer which adversely impact patient survival and allow treatments targeting these processes to be developed.

Menetrier's disease exacerbating ulcerative colitis and relieved by gastrectomy.

Ménétrier's disease (MD) is a rare gastropathy characterised by giant rugal folds which can present with nausea, vomiting, abdominal pain and protein losing gastropathy. We report a 21-year-old woman with comorbid MD and ulcerative colitis (UC). Management was complicated by limited treatment options for MD, significant symptom burden, worsening nutrition and difficulty determining which disease was the predominant cause of symptoms. Since age 18 the patient experienced recurrent UC flares characterised by diarrhoea, persistent vomiting and corticosteroid dependence. Endoscopic assessment demonstrated concurrent MD and active UC. Octreotide and cetuximab were trialled given persistent hypoalbuminaemia and suspicion for MD associated protein-losing gastropathy. UC management comprised dose-optimised infliximab and methotrexate. Repeat endoscopic assessment demonstrated improvement in UC without corresponding improvement in symptoms or hypoalbuminaemia. Nasojejunal feeding and parenteral nutrition failed to significantly improve nutritional status and accordingly the patient proceeded to radical total gastrectomy. Postoperatively, MD-associated symptoms and hypoalbuminemia resolved completely.

Rectal cancer treatment and outcomes in elderly patients treated with curative intent.

The elderly population comprises a significant proportion of patients diagnosed with rectal cancer. However, there is a lack of evidence to guide treatment decisions in this group. Thus, this multicentre study compares the histopathology, treatment patterns and outcomes between the elderly and young populations with non-metastatic rectal cancer. The present study reported on the clinicopathological variables, treatment modalities and survival outcomes in 736 patients diagnosed with non-metastatic rectal cancer between 2006 and 2015. Patients were divided into the following two groups, <70 and ≥70 years of age, which were compared using Chi-square and survival outcome analysis using Kaplan-Meier. Elderly patients made up nearly half of the cohort and were less likely to undergo trimodality therapy or be discussed in a multidisciplinary meeting. Surgery in the elderly patients was associated with increased mortality. Elderly patients had worse cancer-specific survival (75 vs. 85%), which was particularly evident in stage III disease (hazard ratio, 2.1). Elderly patients in this subgroup treated with trimodality therapy had similar survival outcomes to younger patients. Elderly patients with locally advanced rectal cancer comprise a large proportion of the patient cohort. Consideration should be given for trimodality therapy in this group, taking into account biological age, especially in the context of increasing life expectancy and improvement in the management of age-related comorbidities.

Non-transfusion dependent thalassemia is independently associated with higher alloimmunization risk than transfusion dependent thalassemia and would benefit the most from extended red cell antigen-matching.

BACKGROUND: Alloimmunization prevalence is conventionally used to identify RBCs alloimmunization risk factors among thalassemia patients, but it may be confounded by differences in transfusion exposure especially between non-transfusion dependent thalassemia (NTDT) and transfusion dependent thalassemia (TDT) patients. To better identify thalassemia patients with high alloimmunization risks, we used cumulative incidence of first alloimmunization as a function of RBCs transfused to compare alloimmunization risks between TDT and NTDT and to evaluate other risk factors. We also proposed practical strategies to prevent alloimmunization in thalassemia. STUDY DESIGN AND METHODS: Adult TDT and NTDT patients who had received ≥2 transfusions and no alloimmunization before their first transfusion were included. Alloimmunization was defined as the development of clinically significant alloantibodies. We estimated the first alloimmunization incidence from transfusion by Kaplan-Meier analysis with the horizontal axis expressed as cumulative non-antigen-matched RBC units transfused. We compared this incidence between TDT and NTDT, and analyzed for other alloimmunization risk factors and the alloantibody specificities/frequencies. RESULTS: The alloimmunization prevalence was similar between TDT and NTDT (27% vs. 30% respectively, p = .726). However, for the same transfusion exposure, NTDT had higher alloimmunization incidence than TDT (hazard ratio 8.59, 95% confidence interval [2.25-32.74], p = .002), independent of age at first transfusion and last follow-up, gender, and splenectomy. Anti-E, anti-c, anti-Mia , and anti-Jka were most frequent. DISCUSSION: NTDT has the highest alloimmunization risk and would benefit the most from extended RBC antigen-matching, especially C, c, E, and e. Other blood group antigen-matching should be guided by the patient/donor disparities and alloantibody frequencies in different populations.