Biomarker Development Using Liquid Biopsy in Hepatocellular Carcinoma.

Liver cancer incidence rate continues to increase and currently ranks third in the total number of annual deaths, behind only lung and colorectal cancer. Most patients with hepatocellular carcinoma (HCC) are diagnosed at advanced stages, and they live for less than 2 years after diagnosis on average. This contrasts with those diagnosed at an early stage, who can be cured with surgery. However, even after curative resection, there remains a risk of up to 70% of postoperative HCC recurrence. There have been major changes in the management of HCC in the past 5 years, particularly for patients at advanced stages. Despite this multitude of new therapies, there is a lack of clear biomarkers to guide providers on the best approach to sequence therapies, which would maximize efficacy while minimizing toxicity. There are several areas in clinical management of HCC that are particularly challenging, and would benefit from development and implementation of new biomarkers to improve patient overall survival. Here, we review the major advances in liquid biopsy biomarkers for early detection of HCC, minimum residual disease, and predicting response to treatment.

Systematic Review with Meta-Analysis: Fecal Microbiota Transplantation for Severe or Fulminant Clostridioides difficile.

BACKGROUND: Severe and fulminant Clostridioides difficile infection (CDI) is associated with significant morbidity and mortality. While fecal microbiota transplantation (FMT) has proved to be a highly effective treatment for recurrent CDI, its efficacy in severe or fulminant CDI remains uncertain. AIMS: To perform a systematic review with meta-analysis evaluating clinical outcomes and safety of FMT in severe and fulminant CDI. METHODS: A systemic review with meta-analysis was performed through comprehensive search of Embase, Medline (Ovid), trial registers, and conference abstracts through January 2020. Studies on FMT in severe and fulminant CDI were included. Meta-analysis was done with random effects models given heterogeneity to estimate rates of cure, mortality, and colectomy. Publication bias was assessed using Egger's test. RESULTS: Sixteen studies comprised of one randomized controlled trial, four cohort studies, and eleven case series were analyzed. In total, 676 patients underwent FMT for severe or fulminant CDI. The overall rate of clinical cure after single FMT was 61.3% (95% CI 43.2-78.0%) with 10.9% (95% CI 0.2-30.2%) of patients experiencing major adverse events. The overall pooled colectomy rate after FMT was 8.2% (95% CI 0.1-23.7%) with a pooled all-cause mortality rate after FMT of 15.6% (95% CI 7.8-25.0%). CONCLUSION: Low-quality data support the use of fecal microbiota transplantation in patients with severe and fulminant Clostridioides difficile infection.

Impact of COVID-19 pandemic on gastrointestinal cancer diagnosis and resection: An observational study.

BACKGROUND: The COVID-19 pandemic disrupted routine screening for and treatment of gastrointestinal (GI) cancers. We analyzed changes in GI cancer pathology specimens resulting from diagnostic and therapeutic procedures at a single academic center in an epicenter of the COVID-19 pandemic. Our aim was to determine which cancer types, procedures, and patients were impacted by the pandemic. METHODS: This was a retrospective, cohort study of patients identified based on carcinoma containing pathologic specimens reviewed in our institution resulting from diagnostic or resection procedures. Pathology and medical records of patients with GI and liver carcinoma and high-grade dysplasia were reviewed from February 1 to April 30 in 2018, 2019 and 2020. We used March 16, 2020 to delineate the pre-COVID-19 and COVID-19 period in 2020. Chi-squared or t-tests, as appropriate, were used to compare these time periods in each year. Mann Kendall test was used to test for trend in volume. ANCOVA was used to compare differences across years. RESULTS: A total of 1028 pathology samples from 949 unique patients were identified during the study period. There was a 57% drop in samples within 2020 (p = 0.01) that was not present in either 2018 or 2019 (p<0.01). In 2020, there were significantly fewer resections compared to biopsies overall in the COVID-19 period (p = 0.01). There were fewer colorectal cancer specimens (p = 0.04) which were procured from older patients (p<0.01) in the 2020 COVID-19 period compared to pre-COVID-19. CONCLUSIONS: In our institution, there was a significant drop in diagnostic and resection specimens of GI cancers during the COVID-19 pandemic, disproportionately affecting older colorectal cancer patients.

Survey Finds Gender Disparities Impact Both Women Mentors and Mentees in Gastroenterology.

INTRODUCTION: Gastroenterologists at all levels of practice benefit from formal mentoring. Much of the current literature on mentoring in gastroenterology is based on expert opinion rather than data. In this study, we aimed to identify gender-related barriers to successful mentoring relationships from the mentor and mentee perspectives. METHODS: A voluntary, web-based survey was distributed to physicians at 20 academic institutions across the United States. Overall, 796 gastroenterology fellows and faculty received the survey link, with 334 physicians responding to the survey (42% response rate), of whom 299 (90%; 129 women and 170 men) completed mentorship questions and were included in analysis. RESULTS: Responses of women and men were compared. Compared with men, more women preferred a mentor of the same gender (38.6% women vs 4.2% men, P < 0.0001) but less often had one (45.5% vs 70.2%, P < 0.0001). Women also reported having more difficulty finding a mentor (44.4% vs 16.0%, P < 0.0001) and more often cited inability to identify a mentor of the same gender as a contributing factor (12.8% vs 0.9%, P = 0.0004). More women mentors felt comfortable advising women mentees about work-life balance (88.3% vs 63.8%, P = 0.0005). Nonetheless, fewer women considered themselves effective mentors (33.3% vs 52.6%, P = 0.03). More women reported feeling pressured to mentor because of their gender (39.5% vs 0.9% of men, P < 0.0001). Despite no gender differences, one-third of respondents reported negative impact of the COVID-19 pandemic on their ability to mentor and be mentored. DISCUSSION: Inequities exist in the experiences of women mentees and mentors in gastroenterology, which may affect career advancement and job satisfaction.

Limited intestinal inflammation despite diarrhea, fecal viral RNA and SARS-CoV-2-specific IgA in patients with acute COVID-19.

Gastrointestinal symptoms are common in COVID-19 patients but the nature of the gut immune response to SARS-CoV-2 remains poorly characterized, partly due to the difficulty of obtaining biopsy specimens from infected individuals. In lieu of tissue samples, we measured cytokines, inflammatory markers, viral RNA, microbiome composition, and antibody responses in stool samples from a cohort of 44 hospitalized COVID-19 patients. SARS-CoV-2 RNA was detected in stool of 41% of patients and more frequently in patients with diarrhea. Patients who survived had lower fecal viral RNA than those who died. Strains isolated from stool and nasopharynx of an individual were the same. Compared to uninfected controls, COVID-19 patients had higher fecal levels of IL-8 and lower levels of fecal IL-10. Stool IL-23 was higher in patients with more severe COVID-19 disease, and we found evidence of intestinal virus-specific IgA responses associated with more severe disease. We provide evidence for an ongoing humeral immune response to SARS-CoV-2 in the gastrointestinal tract, but little evidence of overt inflammation.

Gender dynamics in education and practice of gastroenterology.

BACKGROUND AND AIMS: With an increasing number of women joining procedural fields, including gastroenterology, optimizing the work environment for learning, teaching, and clinical practice is essential to the well-being of both physicians and their patients. We queried female and male gastroenterologists on their beliefs toward the endoscopy suite environment, as well as their experiences in learning and teaching endoscopic skills. METHODS: We distributed a web-based survey to 403 gastroenterology fellows and practicing gastroenterologists at 12 academic institutions and 3 large private practices. We used univariate and multivariate analysis to compare the responses of female and male gastroenterologists. RESULTS: The overall response rate was 32% (n = 130); 54 women and 61 men completed the survey in its entirety and were included in the analysis (15 respondents did not meet the inclusion criteria). Baseline demographics were comparable between the groups. Overall, fewer women than men were trained using tactile instruction (41% vs 67%; P = .004). Of those trained using tactile instruction, 60.3%, with no gender differences, felt it was also important for endoscopic learning. More women reported experiencing gender bias toward themselves during training (57.4% vs 13.1%; P = .001) as well as in their current careers (50.0% vs 9.8%; P = .001). When queried on treatment of gastroenterologists by endoscopy staff, 75.9% of women reported that men were treated more favorably, whereas 70.5% of men felt that both male and female gastroenterologists were treated equally. CONCLUSIONS: Inequities exist with regard to the experience of men and women in gastroenterology, and specific challenges for women may have an impact on their career choices and ability to safely and effectively learn, teach, and practice endoscopy.

Limited intestinal inflammation despite diarrhea, fecal viral RNA and SARS-CoV-2-specific IgA in patients with acute COVID-19.

We sought to characterize the role of the gastrointestinal immune system in the pathogenesis of the inflammatory response associated with COVID-19. We measured cytokines, inflammatory markers, viral RNA, microbiome composition and antibody responses in stool from a cohort of 44 hospitalized COVID-19 patients. SARS-CoV-2 RNA was detected in stool of 41% of patients and more frequently in patients with diarrhea. Patients who survived had lower fecal viral RNA than those who died. Strains isolated from stool and nasopharynx of an individual were the same. Compared to uninfected controls, COVID-19 patients had higher fecal levels of IL-8 and lower levels of fecal IL-10. Stool IL-23 was higher in patients with more severe COVID-19 disease, and we found evidence of intestinal virus-specific IgA responses associated with more severe disease. We provide evidence for an ongoing humeral immune response to SARS-CoV-2 in the gastrointestinal tract, but little evidence of overt inflammation.

Cooperation Between Distinct Cancer Driver Genes Underlies Intertumor Heterogeneity in Hepatocellular Carcinoma.

BACKGROUND AND AIMS: The pattern of genetic alterations in cancer driver genes in patients with hepatocellular carcinoma (HCC) is highly diverse, which partially explains the low efficacy of available therapies. In spite of this, the existing mouse models only recapitulate a small portion of HCC inter-tumor heterogeneity, limiting the understanding of the disease and the nomination of personalized therapies. Here, we aimed at establishing a novel collection of HCC mouse models that captured human HCC diversity. METHODS: By performing hydrodynamic tail-vein injections, we tested the impact of altering a well-established HCC oncogene (either MYC or ß-catenin) in combination with an additional alteration in one of eleven other genes frequently mutated in HCC. Of the 23 unique pairs of genetic alterations that we interrogated, 9 were able to induce HCC. The established HCC mouse models were characterized at histopathological, immune, and transcriptomic level to identify the unique features of each model. Murine HCC cell lines were generated from each tumor model, characterized transcriptionally, and used to identify specific therapies that were validated in vivo. RESULTS: Cooperation between pairs of driver genes produced HCCs with diverse histopathology, immune microenvironments, transcriptomes, and drug responses. Interestingly, MYC expression levels strongly influenced ß-catenin activity, indicating that inter-tumor heterogeneity emerges not only from specific combinations of genetic alterations but also from the acquisition of expression-dependent phenotypes. CONCLUSIONS: This novel collection of murine HCC models and corresponding cell lines establishes the role of driver genes in diverse contexts and enables mechanistic and translational studies.

HCM-linked ∆160E cardiac troponin T mutation causes unique progressive structural and molecular ventricular remodeling in transgenic mice.

Hypertrophic cardiomyopathy (HCM) is a primary disease of the cardiac muscle, and one of the most common causes of sudden cardiac death (SCD) in young people. Many mutations in cardiac troponin T (cTnT) lead to a complex form of HCM with varying degrees of ventricular hypertrophy and ~65% of all cTnT mutations occur within or flanking the elongated N-terminal TNT1 domain. Biophysical studies have predicted that distal TNT1 mutations, including Δ160E, cause disease by a novel, yet unknown mechanism as compared to N-terminal mutations. To begin to address the specific effects of this commonly observed cTnT mutation we generated two independent transgenic mouse lines carrying variant doses of the mutant transgene. Hearts from the 30% and 70% cTnT Δ160E lines demonstrated a highly unique, dose-dependent disruption in cellular and sarcomeric architecture and a highly progressive pattern of ventricular remodeling. While adult ventricular myocytes isolated from Δ160E transgenic mice exhibited dosage-independent mechanical impairments, decreased sarcoplasmic reticulum calcium load and SERCA2a calcium uptake activity, the observed decreases in calcium transients were dosage-dependent. The latter findings were concordant with measures of calcium regulatory protein abundance and phosphorylation state. Finally, studies of whole heart physiology in the isovolumic mode demonstrated dose-dependent differences in the degree of cardiac dysfunction. We conclude that the observed clinical severity of the cTnT Δ160E mutation is caused by a combination of direct sarcomeric disruption coupled to a profound dysregulation of Ca(2+) homeostasis at the cellular level that results in a unique and highly progressive pattern of ventricular remodeling.