Clinical factors to predict flare-up in patients with inflammatory bowel disease during international air travel: A prospective study

Backgrounds and aims

Inflammatory bowel disease (IBD) patients often experience disease flare-ups during international air travel. We aimed to identify risk factors associated with IBD flare-up during international air travel.

Methods

Patients with scheduled international air travel were enrolled in the study from the Seoul National University Bundang Hospital IBD clinic. Flight information and clinical data were collected via questionnaires and personal interviews, and risk factors associated with IBD flares were determined.

Results

Between May 2018 and February 2020, 94 patients were prospectively enrolled in the study (mean age, 33.0 years; males, 53.2%; mean disease duration, 56.7 months), including 56 (59.6%) with ulcerative colitis and 38 (40.4%) with Crohn’s disease. Of the 94 patients enrolled, 15 (16.0%) experienced an IBD flare-up and 79 (84.0%) remained in remission throughout travel. Logistic regression analysis revealed that high fecal calprotectin levels before travel (odds ratio [OR]: 1.001, 95% confidence interval [CI]: 1.000–1.001, p = 0.016), the presence of a comorbidity (OR: 6.334, 95% CI: 1.129–35.526, p = 0.036), and history of emergency room visit (OR: 5.283, 95% CI: 1.085–25.724, p = 0.039) were positively associated with disease flare-up. The previous and current use of immunomodulators and biologics, time of flight, altitude, number countries visited, travel duration, objective of visit, and previous medical consultations were not associated with disease flare-up.

Conclusions

Elevated fecal calprotectin levels, history of emergency room visits, and the presence of a comorbidity predicted IBD flare-up during international air travel.

Aberrant DNA Methylation Maker for Predicting Metachronous Recurrence After Endoscopic Resection of Gastric Neoplasms

Purpose

To investigate whether MOS methylation can be useful for the prediction of metachronous recurrence after endoscopic resection of gastric neoplasms.

Materials and Methods

From 2012 to 2017, 294 patients were prospectively enrolled after endoscopic resection of gastric dysplasia (n=171) or early gastric cancer (n=123). When H. pylori was positive, eradication therapy was performed. Among them, 124 patients completed the study protocol (follow-up duration > 3 years or development of metachronous recurrence during the follow-up.) Methylation levels of MOS were measured at baseline using quantitative MethyLight assay from the antrum.

Results

Median follow-up duration was 49.9 months. MOS methylation levels at baseline were not different by age, sex, and current H. pylori infection, but they showed a weak correlation with operative link on gastritis assessment (OLGA) or operative link on gastric intestinal metaplasia assessment (OLGIM) stages (Spearman's ρ = 0.240 and 0.174, respectively, p < 0.05). During the follow-up, a total of 20 metachronous gastric neoplasms (13 adenomas and 7 adenocarcinomas) were developed. Either OLGA or OLGIM stage was not useful in predicting the risk for metachronous recurrence. In contrast, MOS methylation high group (≥ 34.82 %) had a significantly increased risk for metachronous recurrence compared to MOS methylation low group (adjusted hazard ratio [95% confidence interval]. 4.76 [1.54,14.79], p=0.007).

Conclusion

MOS methylation can be a promising marker for predicting metachronous recurrence after endoscopic resection of gastric neoplasms. To confirm the usefulness of MOS methylation, validation studies are warranted in the future. (ClinicalTrials No.: NCT04830618).

Gut Microbiome in Probable Intestinal Tuberculosis and Changes following Anti-Tuberculosis Treatment

PURPOSE

Information on the gut microbiome in patients with intestinal tuberculosis (ITB) and changes therein following anti-tuberculosis treatment (ATT) is lacking. We aimed to elucidate differences in stool microbiome between ITB patients and controls and to evaluate stool microbiome changes after ATT.

MATERIALS AND METHODS

Eleven patients with probable ITB underwent ATT for 6 months, with stool samples collected at 0, 2, and 6 months. We performed next-generation sequencing of 16S rRNA genes in stool bacteria and compared the gut microbiome.

RESULTS

Initially, the relative abundance of Verrucomicrobia was higher (5.0% vs. <1%) and that of Proteobacteria was lower (<1% vs. 6.6%) in ITB patients than in controls. Higher numbers of butyrate-producing bacteria (Blautia and Roseburia) were noted in ITB patients. The alpha-diversity of stool microbiome of ITB patients was lower than that in controls (p=0.045). There was a significant difference in beta-diversity between the groups (p=0.001). At 6 months, the proportion of Verrucomicrobia decreased to <1%, while the proportion of Proteobacteria remained at <1%.

CONCLUSION

There were no significant differences in alpha- and beta-diversity in the stool microbiome at 0, 2, and 6 months after ATT. The stool microbiome composition of probable ITB patients was different from that of controls, and 6 months of ATT did not significantly affect it.

Risk of Psoriasis in Postgastrectomy Gastric Cancer Survivors: A Nationwide Population-Based Cohort Study

Background

Although patients with psoriasis have an increased risk of cancers, little is known about the risk of psoriasis in cancer patients.

Objective

We aimed to comparatively analyze the incidence and risk factors of psoriasis in gastric cancer patients who underwent gastrectomy and in the general population.

Methods

A nationwide retrospective cohort of 52,608 gastric cancer survivors (2007~2015) was compared to 123,438 matched controls from the general population to estimate the incidence and hazard ratio (HR) of new-onset psoriasis. We also calculated the HRs for psoriasis according to adjuvant cancer treatment, obesity, and vitamin B₁₂ supplementation in gastric cancer survivors.

Results

During a mean follow-up of 6.85 years, 645 of the 52,608 gastric cancer patients developed psoriasis, while 1,806 in the 123,438 matched control group developed psoriasis. Gastric cancer patients had a decreased risk of psoriasis (HR, 0.86; 95% confidence interval, 0.79~0.94), especially those who underwent subtotal gastrectomy. We found that vitamin B₁₂ supplementation for more than 3 years had an additive effect on decreasing the risk of psoriasis in gastric cancer patients who underwent subtotal gastrectomy. Total gastrectomy, radio/chemotherapy, and obesity did not affect the risk of psoriasis in gastric cancer survivors.

Conclusion

The incidence of psoriasis is slightly lower in gastric cancer survivors than in the general population. Our results suggest that the development of psoriasis may be reduced by removing the source of systemic inflammation caused by Helicobacter pylori infection through subtotal gastrectomy in gastric cancer survivors.

Nationwide cohort study: cholesterol level is inversely related with the risk of gastric cancer among postmenopausal women

BACKGROUND

Recent studies showed inverse relationship between hypercholesterolemia and the risk of gastric cancer, especially among male. However evidence among female is inconsistent. We aimed to investigate the relationship between cholesterol level and the risk of gastric cancer among female according to menopausal status.

METHODS

We analyzed the data from a population-based prospective cohort of female ≥ 30 years old who underwent cancer screening and general health screening provided by the Korean National Health Insurance Corporation in 2009. Under quartile stratification of the level of cholesterol components, we calculated the hazard ratio (HR) for gastric cancer incidence until 2018 for each level group according to the menopausal status at 2009.

RESULTS

Among total 2,722,614 individuals, 17,649 gastric cancer cases developed after mean 8.26 years of follow-up (premenopausal 3746/1180666; postmenopausal 13,903/1541948). Total cholesterol, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) showed inverse relationship with the risk of gastric cancer among postmenopausal women (adjusted HR (95% confidence interval) for the highest quartile vs. lowest quartile and p-for-trend: 0.88 (0.84-0.92) and < 0.001 for total cholesterol; 0.89 (0.85-0.92) and < 0.001 for HDL-C; 0.92 (0.89-0.97) and 0.001 for LDL-C), whereas none showed statistically significant risk relationship among premenopausal women. Triglyceride was not independently related with gastric cancer risk among both pre- and postmenopausal women.

CONCLUSIONS

Cholesterol levels, including total cholesterol, HDL-C, and LDL-C, are inversely related with the risk of gastric cancer among postmenopausal women, but not among premenopausal women.

rs2671655 single nucleotide polymorphism modulates the risk for gastric cancer in Helicobacter pylori-infected individuals: a genome-wide association study in the Korean population

OBJECTIVE

To identify genetic variations which is associated with gastric cancer (GC) risk according to Helicobacter pylori infection.

METHODS

This study incorporated 527 GC patients and 441 controls from a cohort at Seoul National University Bundang Hospital. The associations between GC risk and single nucleotide polymorphisms were calculated, stratified by H. pylori status, adjusting for age, sex, and smoking. mRNA expression from non-cancerous gastric mucosae was evaluated using reverse transcription quantitative polymerase chain reaction.

RESULTS

In the entire cohort, genome-wide association study showed no significant variants reached the genome-wide significance level. In the H. pylori-positive group, rs2671655 (chr17:47,468,020;hg19, GH17J049387 enhancer region) was identified at a genome-wide significance level, which was more pronounced in diffuse type GC. There was no significant variant in the H. pylori-negative group, indicating the effect modification of rs2671655 by H. pylori. Among the target genes of GH17J049387 enhancer (PHB1, ZNF652 and SPOP), PHB1 mRNA was expressed more in cases than in controls, who were not affected by H. pylori. By contrast, an increase in ZNF652 and SPOP in GC was observed only in the H. pylori-negative group (P < 0.05). Mediation analysis showed that PHB1 (P = 0.0238) and SPOP (P = 0.0328) mediated the effect of rs2671655 on GC risk. The polygenic risk score was associated with the number of rs2671655 risk alleles only in the H. pylori-positive group (P = 0.0112).

CONCLUSION

After H. pylori infection, rs2671655 may increase GC risk, especially in diffuse-type GC, by regulating the expression of several genes that consequently modify susceptibility to GC.

Outcome of Initial Progression During Nivolumab Treatment for Hepatocellular Carcinoma: Should We Use iRECIST?

Immune response evaluation criteria in solid tumors (iRECIST) is recommended during immune checkpoint inhibitors (ICIs) treatment, due to the possibility of pseudoprogression. We evaluated the frequency of pseudoprogression in hepatocellular carcinoma (HCC) patients. This retrospective multicenter study involved 158 consecutive patients who underwent nivolumab treatment for HCC in Korea. At the initial evaluation, 94 patients presented with immune unconfirmed progressive disease, and 22 continued nivolumab. At the second evaluation, 21 of the 22 patients (95.5%) had confirmed progression and no pseudoprogression was observed. Considering low possibility of pseudoprogression, iRECIST may not be required for HCC.

Fecal Microbial Enterotypes Differentially Respond to a High-fat Diet Based on Sex in Fischer-344 Rats

The gut microbiota interacts with the host gut environment, which is influenced by such factors as sex, age, and host diet. These factors induce changes in the microbial composition. The aim of this study was to identify differences in the gut microbiome of Fisher-344 (F344) rats fed a high-fat diet (HFD), depending on their age and sex. Fecal microbiomes from 6-, 31-, and 74-week-old, and 2-year-old both male and female rats (corresponding to 5-, 30-, 60-, and 80-year-old humans) were analyzed using 16S rRNA gene sequencing, phylogenetic investigation of communities by reconstruction of unobserved states, and enterotype (E) assessment. Moreover, the effect of an HFD on colonic epithelial cells was measured using real-time quantitative PCR. Alpha diversity decreased in the HFD group regardless of age and sex. Based on the enterotype clustering of the whole fecal microbiome, clusters from male rats were divided into E1 and E2 enterotypes, while clusters from female rats were divided into E1, E2, and E3 enterotypes. The female E3 group showed a significantly high abundance in the Ruminococcus genus and expression of Tlr2 mRNA, which may reflect compensation to the HFD. Moreover, the female E3 group showed a lower ratio of opportunistic pathogenic strains to commensal strains compared to the female E2 group. Administration of an HFD influenced the rat fecal microbiota in all assessed age groups, which could be further differentiated by sex. In particular, female rats showed a compensatory enterotype response to an HFD compared to male rats.

Quantitative Assessment of Fatty Liver using Ultrasound with Normalized Local Variance Technique

PURPOSE

 To assess the diagnostic performance of the normalized local variance (NLV) ultrasound technique in the detection of the fatty liver using histopathology as a reference standard.

MATERIALS AND METHODS

 We prospectively enrolled 194 consecutive patients with clinical suspicion of diffuse liver disease or history of liver transplantation. Conventional grayscale ultrasound and NLV examinations were performed and immediately followed by liver biopsies. The degrees of fatty liver, necroinflammatory activity, and fibrosis stage were evaluated by histopathological assessment. The diagnostic performance of the NLV values in detecting each grade of fatty liver was determined using receiver operating characteristics analyses, and multivariate linear regression analyses were performed to identify variables significantly associated with the NLV values.

RESULTS

 The number of patients in each degree of fatty liver and hepatic fibrosis was 118/37/26/13 and 81/68/24/6/14 for none/mild/moderate/severe steatosis and F0 / F1/F2 / F3/F4 fibrosis on histopathological examinations, respectively. The area under the receiver operating characteristics curve and optimal cut-off NLV value for detecting fatty liver of varying degrees were 0.911 and 1.095 for ≥ S1, 0.974 and 1.055 for ≥ S2, and 0.954 and 1.025 for ≥ S3, respectively. Multivariate analyses revealed that not fibrosis or inflammation but rather the degree of steatosis was associated with the NLV value.

CONCLUSION

 The NLV value demonstrated excellent diagnostic performance for detecting varying degrees of fatty liver, and the degree of steatosis on histopathological examinations was the only significant factor affecting the NLV value.

Comparison of Overall Survival between Surgical Resection and Radiofrequency Ablation for Hepatitis B-Related Hepatocellular Carcinoma

Simple Summary

The effectiveness of surgical resection and radiofrequency ablation in early hepatocellular carcinoma is still controversial because previous studies show conflicting results. In addition, previous studies did not consider the antiviral treatment-related factors, even though there is now robust evidence that antiviral therapy is crucial for determining the prognosis of patients with chronic hepatitis B-related liver cancer. After adjusting for the antiviral treatment, we demonstrated that radiofrequency ablation may provide comparable overall survival to resection in the treatment of very early or early hepatocellular carcinoma, although recurrence-free survival is marginally shorter than in the resection group.

Abstract

It remains controversial whether surgical resection, compared to radiofrequency ablation (RFA), improves overall survival (OS) in patients with early hepatocellular carcinoma (HCC). This study aimed to compare OS after RFA with that after resection for HCC. This retrospective study included patients who underwent RFA or surgical resection as initial treatment for hepatitis B virus (HBV)-related HCC at a very early or early stage. A total of 761 patients (RFA, n = 194; resection, n = 567) from Seoul National University Hospital (Seoul, South Korea) and 1277 patients (RFA, n = 352; resection, n = 925) from the Korean Primary Liver Cancer Registry were included in the hospital and nationwide cohorts, respectively. Primary and secondary endpoints were OS and recurrence-free survival (RFS), respectively. Additional analysis was performed when the history of the antiviral treatment and the type of prescribed nucleos(t)ide analogue were confirmed. The rate of complications was compared between the two treatment groups in the hospital cohort. Baseline characteristics were balanced, using inverse probability of treatment weighting (IPTW). In the hospital cohort, the RFA group had a smaller mean tumor size (1.7 vs. 3.9 cm) but a higher proportion of cirrhotic patients than the resection group (85.6% vs. 63.1%) (both p < 0.01). During 81.0 (interquartile range, 62.3–107.1) months of follow-up, there was no difference in OS (adjusted hazard ratio (aHR) = 0.870, 95% confidence interval (CI) = 0.400–1.897, p = 0.73) and RFA was associated with shorter RFS (aHR = 1.562, 95% CI = 1.099–2.219, p = 0.01) after employing IPTW. Antiviral treatment was independently associated with longer OS (aHR = 0.444, 95% CI = 0.251–0.786, p = 0.01) as well as RFS (aHR = 0.544, 95% CI = 0.391–0.757, p < 0.01) in the hospital cohort. In the nationwide cohort, there was no difference in OS (aHR = 0.981, 95% CI = 0.661–1.456, p = 0.92) between the two treatment groups when adjusted for antiviral treatment, which was a negative independent risk factor for mortality (aHR = 0.655, 95% CI = 0.451–0.952, p = 0.03) after IPTW. Among patients treated with tenofovir (n = 96) or entecavir (n = 184) in the hospital cohort, there was no difference in either OS (aHR = 0.522, 95% CI = 0.058–4.724, p = 0.56) or RFS (aHR = 1.116, 95% CI = 0.738–1.688, p = 0.60). The overall incidence of complications was higher in the resection group (26.3%) than in the RFA group (13.9%) (p < 0.01). RFA may provide comparable OS to resection in the treatment of very early or early HCC with a lower rate of complications, although RFS is marginally shorter than in the resection group after adjusting for antiviral treatment. Regardless of the type of NA, antiviral treatment in patients with HBV-related HCC is strongly associated with both OS and RFS.

First-in-human phase 1 study of the anti-TIGIT antibody vibostolimab as monotherapy or with pembrolizumab for advanced solid tumors, including non-small cell lung cancer

BACKGROUND

In this first-in-human phase 1 study, we investigated the safety and efficacy of the anti-TIGIT antibody vibostolimab as monotherapy or in combination with pembrolizumab.

METHODS

Part A enrolled patients with advanced solid tumors and part B enrolled patients with non-small cell lung cancer (NSCLC). Patients received vibostolimab 2.1-700 mg alone or with pembrolizumab 200 mg in part A and vibostolimab 200 mg alone or with pembrolizumab 200 mg in part B. Primary end points were safety and tolerability. Secondary end points included pharmacokinetics and objective response rate (ORR) per RECIST v1.1.

RESULTS

Part A enrolled 76 patients (monotherapy, 34; combination therapy, 42). No dose-limiting toxicities were reported. Across doses, 56% of patients receiving monotherapy and 62% receiving combination therapy had treatment-related adverse events (TRAEs); grade 3-4 TRAEs occurred in 9% and 17% of patients, respectively. The most common TRAEs were fatigue (15%) and pruritus (15%) with monotherapy and pruritus (17%) and rash (14%) with combination therapy. Confirmed ORR was 0% with monotherapy and 7% with combination therapy. In part B, 39 patients had anti-PD-1/PD-L1-naïve NSCLC (all received combination therapy) and 67 had anti-PD-1/PD-L1-refractory NSCLC (monotherapy, 34; combination therapy, 33). In patients with anti-PD-1/PD-L1-naive NSCLC: 85% had TRAEs-the most common were pruritus (38%) and hypoalbuminemia (31%); confirmed ORR was 26%, with responses occurring in both PD-L1-positive and PD-L1-negative tumors. In patients with anti-PD-1/PD-L1‒refractory NSCLC: 56% receiving monotherapy and 70% receiving combination therapy had TRAEs-the most common were rash and fatigue (21% each) with monotherapy and pruritus (36%) and fatigue (24%) with combination therapy; confirmed ORR was 3% with monotherapy and 3% with combination therapy.

CONCLUSION

Vibostolimab plus pembrolizumab was well tolerated and demonstrated antitumor activity in patients with advanced solid tumors, including patients with advanced NSCLC.

Transcriptional upregulation of multiple earthworm chitinase genes following bacterial challenge suggests their implications in innate immunity

BACKGROUND

Chitinase is a multi-functional enzyme that catalyzes the hydrolysis of β-1,4-linkages between N-acetylglucosamines (GlcNAc) in chitin. Recent studies imply that earthworm chitinase is implicated in self-defense immunity against chitin-containing pathogens. However, a direct relationship of earthworm chitinase with innate immunity has not yet been established.

OBJECTIVE

In this study, earthworm (Eisenia andrei) chitinase expression was examined following bacterial challenge by Bacillus subtilis.

METHODS

RNA sequencing (RNA-seq) and real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to quantitatively evaluate mRNA expression changes in response to bacterial stimulation.

RESULTS

Multiple chitinase-related mRNAs were found to be upregulated, among which EaChi3, EaChi4, and EaChi2 were upregulated by approximately eightfold, eightfold, and 2.5-fold, respectively. This strongly suggested that earthworm chitinases may act as inducible humoral effectors in earthworm innate immunity. The primary structures of all three chitinases contained an N-terminal glycol_18 domain with two chitin-binding and chitin-catalyzing domains, and a C-terminal proline, glycine, serine, threonine (PGST)-rich domain. In addition, EaChi2 had a chitin-binding peritrophin-A domain at the end of the C-terminus with 5 cysteine residues possibly contributing two intradomain disulfide bonds. Multiple sequence alignment of the catalytic domain centers of glycol_18 domain displayed highly conserved chitin-binding and chitin-catalyzing domains in which three essential amino acid residues (D, D, E) for catalyzing activity are well conserved except EaChi4. The critical glutamic acid (E) residue was substituted for glutamine (Q) in EaChi4 indicating that it is devoid of catalytic activity.

CONCLUSIONS

To our knowledge, this is the first report providing direct evidence that multiple earthworm chitinases are bacteria-responsive, strongly suggesting that earthworm chitinases are inducible humoral effectors in earthworm innate immunity. In addition, our results possibly suggest that earthworm EaChi4 may function as a pattern recognition molecule modulating the downstream immune pathway.

Noninvasive assessment of hepatic steatosis using a pathologic reference standard: comparison of CT, MRI, and US-based techniques

Purpose

The present study compared the performance of computed tomography (CT), magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF), controlled attenuation parameter (CAP), grayscale ultrasonography (US), and attenuation imaging (ATI) for the diagnosis of hepatic steatosis (HS).

Methods

In total, 120 prospectively recruited patients who underwent hepatic resection between June 2018 and June 2020 were retrospectively analyzed. CT, MRI-PDFF, CAP, grayscale US, and ATI were performed within 3 months before surgery. Diagnostic performance for HS ≥5% and HS >33% was compared using the area under the curve (AUC) of receiver operating characteristic curves. Histopathologic examinations served as the reference standard for the degree of HS.

Results

For detecting HS ≥5%, MRI-PDFF (AUC, 0.946) significantly outperformed CT, CAP and grayscale US (AUC, 0.807, 0.829, and 0.761, respectively) (P<0.01 for all). ATI (AUC, 0.892) was the second-best modality and significantly outperformed grayscale US (P=0.001). In pairwise comparisons, there were no significant differences between the AUC of ATI and the values of MRI-PDFF, CT, or CAP (P=0.133, P=0.063, and P=0.150, respectively). For detecting HS >33%, all the modalities provided good diagnostic performance without significant differences (AUC, 0.887-0.947; P>0.05 for all).

Conclusion

For detecting HS ≥5%, MRI-PDFF was the best imaging modality, while ATI outperformed grayscale US. For detecting HS >33%, all five imaging tools demonstrated good diagnostic performance.

No-Touch vs. Conventional Radiofrequency Ablation Using Twin Internally Cooled Wet Electrodes for Small Hepatocellular Carcinomas: A Randomized Prospective Comparative Study

Objective

This study aimed to compare the efficacy between no-touch (NT) radiofrequency ablation (RFA) and conventional RFA using twin internally cooled wet (TICW) electrodes in the bipolar mode for the treatment of small hepatocellular carcinomas (HCC).

Materials and Methods

In this single-center, two-arm, parallel-group, prospective randomized controlled study, we performed a 1:1 random allocation of eligible patients with HCCs to receive NT-RFA or conventional RFA between October 2016 and September 2018. The primary endpoint was the cumulative local tumor progression (LTP) rate after RFA. Secondary endpoints included technical conversion rates of NT-RFA, intrahepatic distance recurrence, extrahepatic metastasis, technical parameters, technical efficacy, and rates of complications. Cumulative LTP rates were analyzed using Kaplan-Meier analysis and the Cox proportional hazard regression model. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat and as-treated analyses were performed.

Results

Enrolled patients were randomly assigned to the NT-RFA group (37 patients with 38 HCCs) or the conventional RFA group (36 patients with 38 HCCs). Among the NT-RFA group patients, conversion to conventional RFA occurred in four patients (10.8%, 4/37). According to intention-to-treat analysis, both 1- and 3-year cumulative LTP rates were 5.6%, in the NT-RFA group, and they were 11.8% and 21.3%, respectively, in the conventional RFA group (p = 0.073, log-rank). In the as-treated analysis, LTP rates at 1 year and 3 years were 0% and 0%, respectively, in the NT-RFA group sand 15.6% and 24.5%, respectively, in the conventional RFA group (p = 0.004, log-rank). In as-treated analysis using multivariable Cox regression analysis, RFA type was the only significant predictive factor for LTP (hazard ratio = 0.061 with conventional RFA as the reference, 95% confidence interval = 0.000–0.497; p = 0.004). There were no significant differences in the procedure characteristics between the two groups. No procedure-related deaths or major complications were observed.

Conclusion

NT-RFA using TICW electrodes in bipolar mode demonstrated significantly lower cumulative LTP rates than conventional RFA for small HCCs, which warrants a larger study for further confirmation.

Fecal Microbiota and Gut Microbe-Derived Extracellular Vesicles in Colorectal Cancer

The human microbiota comprises trillions of microbes, and the relationship between cancer and microbiota is very complex. The impact of fecal microbiota alterations on colorectal cancer (CRC) pathogenesis is emerging. This study analyzed changes in the microbial composition in CRC subjects with both fecal microbiota and gut microbe-derived extracellular vesicles (EVs). From August 2017 to August 2018, 70 CRC patients and 158 control subjects were enrolled in the study. Metagenomic profiling of fecal microbiota and gut microbe-derived EVs in stool was performed using 16S ribosomal DNA sequencing. Relative abundance, evenness, and diversity in both the gut microbiota and gut microbe-derived EVs were analyzed. Additionally, microbial composition changes according to the stage and location of CRC were analyzed. Microbial composition was significantly changed in CRC subjects compared to control subjects, with evenness and diversity significantly lower in the fecal microbiota of CRC subjects. Gut microbe-derived EVs of stool demonstrated significant differences in the microbial composition, evenness, and diversity in CRC subjects compared to the control subjects. Additionally, microbial composition, evenness, and diversity significantly changed in late CRC subjects compared to early CRC subjects with both fecal microbiota and gut microbe-derived EVs. Alistipes-derived EVs could be novel biomarkers for diagnosing CRC and predicting CRC stages. Ruminococcus 2-derived EVs significantly decreased in distal CRC subjects than in proximal CRC subjects. Gut microbe-derived EVs in CRC had a distinct microbial composition compared to the controls. Profiling of microbe-derived EVs may offer a novel biomarker for detecting and predicting CRC prognosis.

Favorable outcomes of rescue second- or third-line culture-based Helicobacter pylori eradication treatment in areas of high antimicrobial resistance

BACKGROUND

Failure of second or third-line eradication treatment against Helicobacter pylori (H. pylori) is principally caused by antimicrobial resistance and reduced treatment adherence.

AIMS

To evaluate the efficacy and safety of culture-based rescue eradication treatments in patients who have previously experienced failed eradication treatment.

METHODS

Patients who had persistent H. pylori infection following at least one eradication treatment were recommended to undergo culture analysis to determine the minimal inhibitory concentrations of various antimicrobials via endoscopic resection. Consenting patients were assigned one of four therapeutic treatments based on an algorithm determined by antimicrobial resistance. These treatments consisted of 7 or 14-day administration of clarithromycin-containing proton pump inhibitor (PPI) triple therapy; esomeprazole, moxifloxacin, and amoxicillin (MEA) therapy; esomeprazole, bismuth, metronidazole, and tetracycline (quadruple) therapy; or lansoprazole, rifabutin, and amoxicillin (RLA) therapy. Eradication efficacy, adherence, and adverse events were assessed aside clinical outcomes.

RESULTS

A total of 132 patients were enrolled, with 84 patients completing the study. The overall resistance rates to amoxicillin, clarithromycin, metronidazole, and moxifloxacin were 13.1%, 83.3%, 47.6%, and 71.4%, respectively. The patients were allocated to the PPI triple (n = 11), MEA (n = 15), quadruple (n = 53), or RLA triple (n = 5) therapy group. The eradication rates in the intention-to-treat and per-protocol analyses were 90.5% (76 of 84 patients) and 93.8% (76 of 81 patients), respectively. Nausea was the most frequent adverse event (25.0%).

CONCLUSIONS

As a rescue therapy, culture-based susceptibility-guided eradication treatment was both effective and safe, even for patients exhibiting high antimicrobial resistance.

Quantification of Liver Fat Content with Ultrasound: A WFUMB Position Paper

New ultrasound methods that can be used to quantitatively assess liver fat content have recently been developed. These quantitative ultrasound (QUS) methods are based on the analysis of radiofrequency echoes detected by the transducer, allowing calculation of parameters for quantifying the fat in the liver. In this position paper, after a section dedicated to the importance of quantifying liver steatosis in patients with non-alcoholic fatty liver disease and another section dedicated to the assessment of liver fat with magnetic resonance, the current clinical studies performed using QUS are summarized. These new methods include spectral-based techniques and techniques based on envelope statistics. The spectral-based techniques that have been used in clinical studies are those estimating the attenuation coefficient and those estimating the backscatter coefficient. Clinical studies that have used tools based on the envelope statistics of the backscattered ultrasound are those performed by using the acoustic structure quantification or other parameters derived from it, such as the normalized local variance, and that performed by estimating the speed of sound. Experts' opinions are reported.

Tumor volume measured using MR volumetry as a predictor of prognosis after surgical resection of single hepatocellular carcinoma

PURPOSE

To evaluate the clinical value of tumor volume-measurement using magnetic resonance (MR) volumetry for predicting prognosis after surgical resection of single small-to-medium-sized hepatocellular carcinoma (HCC) (≤5cm).

METHOD

This retrospective study included 162 consecutive patients who underwent preoperative gadoxetic acid-enhanced MRI and subsequent surgical resection for single HCC (≤5cm). Tumor volume was measured at hepatobiliary phase of MR images using semi-automated three-dimensional volumetric software program. Recurrence-free survival (RFS) and overall survival (OS) were estimated using Kaplan-Meier method. The Cox-proportional-hazard-model was used to evaluate clinical, pathologic, and radiologic prognostic factors. A minimal p-value approach based on log-rank test statistics was used to obtain the optimal-cutoff tumor volume for predicting RFS and OS. Inter-examiner reproducibility of MR volumetric measurements was assessed using intraclass correlation coefficient (ICC) and coefficient of variance (CV).

RESULTS

After a median follow-up of 84.4 months (range, 2.8-126.5), HCC recurrence occurred in 69 (42.6%) patients and twenty-four (14.8%) patients died with estimated 5-year OS of 90.8%. Larger tumor volume was significantly associated with poor RFS(P = 0.018) and poor OS(P = 0.005) in multivariate analysis. For predicting RFS and OS after surgery, the optimal-cutoff of tumor volume was set at 4.0 mL and 4.0 mL, respectively, with larger volume ≥4.0 mL was significantly associated with poor RFS (hazard ratio[HR], 1.84, P = 0.023) and poor OS (HR, 2.66, P = 0.033). Inter-examiner reproducibility of tumor volume-measurement using MR-volumetry showed ICC of 0.980 and CV of 3.9%.

CONCLUSIONS

Tumor volume-measurement using MR-volumetry is clinically feasible and reproducible, and can help predict RFS and OS after resection of single small-to-medium-sized HCC.

Diagnostic performance of ultrasound attenuation imaging for assessing low-grade hepatic steatosis

OBJECTIVES

To investigate the diagnostic performance of attenuation imaging (ATI) for the assessment of low-grade hepatic steatosis using liver biopsy as the reference standard.

METHODS

The study included 57 potential donor candidates for living liver transplantation who underwent ATI, transient elastography (TE), and liver biopsy for evaluation of hepatic steatosis between February 2020 and April 2020. The attenuation coefficient (AC) from ATI and the controlled attenuation parameter (CAP) from TE were measured for each participant in a random and blind manner. The histologic hepatic fat fraction (HFF) was graded (S0, < 5%; S1, 5-33%; S2, 33-66%; S3, > 66%). The accuracy of ATI for diagnosing hepatic steatosis was compared with that of CAP using ROC analysis. Correlations between AC and HFF were evaluated, and factors affecting AC were determined by linear regression analysis.

RESULTS

The median HFF was 3% (range: 0-35%), with 31 (54.4%), 24 (42.0%), and 2 (3.5%) participants being graded as S0, S1, and S2, respectively. The AUCs for the ROCs of AC and CAP for the detection of hepatic steatosis were 0.808 (95% CI: 0.682-0.900) and 0.829 (95% CI: 0.706-0.916), respectively, with the difference not being statistically significant (p = 0.762). AC showed 61.5% of sensitivity and 90.3% of specificity. AC was positively correlated with HFF (p < 0.001). HFF was the only factor significantly affecting AC.

CONCLUSIONS

ATI showed moderate sensitivity and high specificity in the diagnosis and quantification of hepatic steatosis in low-grade steatosis without fibrosis. Only HFF significantly affected AC.

KEY POINTS

• Attenuation imaging showed moderate sensitivity and high specificity performance in the diagnosis and quantification of hepatic steatosis in low-grade steatosis without fibrosis. • The diagnostic performance of the attenuation coefficient by attenuation imaging did not significantly differ from that of the controlled attenuation parameter by transient elastography in quantifying low-grade steatosis. • The histopathologically determined hepatic fat fraction was the only factor significantly affecting the attenuation coefficient.

Multiparametric US for Identifying Patients with High-Risk NASH: A Derivation and Validation Study

Background Nonalcoholic fatty liver disease (NAFLD) is common in the general population but identifying patients with high-risk nonalcoholic steatohepatitis (NASH) who are candidates for pharmacologic therapy remains a challenge. Purpose To develop a score to identify patients with high-risk NASH, defined as NASH with an NAFLD activity score (NAS) of 4 or greater and clinically significant fibrosis (stage 2 [F2] or higher). Materials and Methods This was a cross-sectional secondary analysis of data prospectively collected between April 2017 and March 2019 for a group of patients with NAFLD in Japan (Japan NAFLD, the derivation data set) with contemporaneous two-dimensional shear-wave elastography and biopsy-proven NAFLD (age range, 20-89 years). Three US markers (liver stiffness [LS, measured in kilopascals], attenuation coefficient [AC, measured in decibels per centimeter per megahertz], and dispersion slope [DS, measured in meters per second per kilohertz]) were determined, together with aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the AST-to-ALT ratio. The best-fit multivariate logistic regression model for identifying patients with high-risk NASH was determined. Diagnostic performance was assessed by using the area under the receiver operating characteristic curve (AUC). The findings were validated in an independent data set (Korea NAFLD; age range, 20-78 years). Results The Japan NAFLD data set included 111 patients (mean age, 53 years ± 18 [standard deviation]; 57 men), 84 (76%) with NASH. The Korea NAFLD data set included 102 patients (mean age, 48 years ± 18; 43 men), 55 (36%) with NASH. The most predictive model (LAD NASH score) combined LS, AC, and DS. Performance was satisfactory in both the derivation sample (AUC, 0.86; 95% CI: 0.79, 0.93) and the validation sample (AUC, 0.88; 95% CI: 0.80, 0.95). The LAD NASH score showed a positive predictive value of 86.5% and a negative predictive value of 87.5% for high-risk NASH in the derivation sample. Conclusion A score combining three US markers may be useful for noninvasive identification of patients with high-risk nonalcoholic steatohepatitis for inclusion in clinical trials and pharmacologic therapy. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Lockhart in this issue.

Role of Serum Pepsinogen II and Helicobacter pylori Status in the Detection of Diffuse-Type Early Gastric Cancer in Young Individuals in South Korea

Background/Aims

The utility of serum pepsinogen (sPG) I and the sPGI/II ratio as biomarkers for screening individuals with gastric cancer (GC) has not been established in Korea. The aim of this study was to define the role of sPG, especially sPGII, in GC screening.

Methods

This study enrolled 2,940 subjects, including patients with GC (n=1,124) or gastric dysplasia (n=353) and controls (n=1,463). Tests to determine sPG levels and Helicobacter pylori (HP) infection status were performed. Area under the curve and receiver operating characteristic curve were calculated to identify the optimal cutoff values for sPG. The usefulness of sPG levels for the detection of GC and gastric dysplasia was validated by multivariate logistic regression.

Results

The sPGI/II ratio was associated with the risk of gastric dysplasia and advanced-stage intestinal-type GC (IGC). In contrast, sPGII was associated with the risk of early-stage diffuse-type GC (DGC). Significantly higher risk was indicated by an sPGI/II ratio <3 for gastric dysplasia and advanced-stage IGC and by sPGII levels ≥20 µg/L for early-stage DGC. Positive HP status showed a stronger association with DGC than with IGC. When sPGII level and HP status were combined, the prevalence of DGC was higher in the ≥20 µg/L sPGII and HP-positive group. Age younger than 40 years was strongly related to early-stage DGC, especially in females (odds ratio, 21.00; p=0.006).

Conclusions

sPGII ≥20 ng/mL and positive HP status suggest a risk of early-stage DGC, particularly in young adult females in South Korea.

The Incidence and Risk Factors for Metachronous Gastric Cancer in the Remnant Stomach after Gastric Cancer Surgery

Background/Aims

Less invasive surgical treatment is performed in East Asia to preserve postoperative digestive function and reduce complications such as postgastrectomy syndromes, but there is an issue of metachronous gastric cancer (GC) in the remaining stomach. This study aimed to analyze the incidence of metachronous GC and its risk factors in patients who had undergone partial gastrectomy.

Methods

A total of 3,045 GC patients who had undergone curative gastric partial resection at Seoul National University Bundang Hospital were enrolled and analyzed retrospectively for risk factors, including age, sex, smoking, alcohol, Helicobacterpylori status, family history of GC, histological type, and surgical method.

Results

Metachronous GC in the remaining stomach occurred in 35 of the 3,045 patients (1.1%) 23 in the distal gastrectomy group (18 with Billroth-I anastomosis, five with Billroth-II anastomosis), seven in the proximal gastrectomy (PG) group, and five in the pylorus-preserving gastrectomy (PPG) group. Univariate and multivariate Cox regression analyses showed that age ≥60 years (p=0.005) and surgical method used (PG or PPG, p<0.001) were related risk factors for metachronous GC, while male sex and intestinal type histology were potential risk factors.

Conclusions

Metachronous GC was shown to be related to older age and the surgical method used (PG or PPG). Regular and careful follow-up with endoscopy should be performed in the case of gastric partial resection, especially in patients with male sex and intestinal type histology as well as those aged ≥60 years undergoing the PG or PPG surgical method.

Randomised clinical trial: comparison of tegoprazan and placebo in non-erosive reflux disease

BACKGROUND

Tegoprazan is a novel, fast- and long-acting potassium-competitive acid blocker that suppresses gastric acid secretion, which could benefit patients with non-erosive reflux disease (NERD), a type of gastroesophageal reflux disease.

AIM

To evaluate the efficacy and safety profiles of tegoprazan compared with those of a placebo in Korean patients with NERD.

METHODS

In this phase 3, double-blind, placebo-controlled, multicentre study, 324 Korean patients with NERD were randomised into three treatment groups: tegoprazan 50 mg, tegoprazan 100 mg and placebo. These drugs were provided once daily for 4 weeks. The primary endpoint was the proportion of patients with complete resolution of major symptoms (both heartburn and regurgitation) for the last 7 days of the 4-week treatment period. Other outcomes related to efficacy, safety and tolerability were also evaluated.

RESULTS

Among all, 42.5% (45/106), 48.5% (48/99) and 24.2% (24/99) of patients showed complete resolution of major symptoms at week 4 after receiving tegoprazan 50 mg, tegoprazan 100 mg, and placebo, respectively. Both doses of tegoprazan showed superior efficacy than the placebo (P = 0.0058 and P = 0.0004, respectively). The complete resolution rates of heartburn and proportions of heartburn-free days (as other efficacy outcomes) were significantly higher in both tegoprazan groups than in the placebo group (P < 0.05 for all). No significant difference in the incidence of treatment-emergent adverse events were noted.

CONCLUSIONS

Tegoprazan 50 and 100 mg showed superior therapeutic efficacy compared with the placebo, as well as a favourable safety profile in patients with NERD. Registration number: ClinicalTrials.gov identifier NCT02556021.

Outcome of No-Touch Radiofrequency Ablation for Small Hepatocellular Carcinoma: A Multicenter Clinical Trial

Background Recently introduced no-touch radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) has the potential to improve local tumor control. Purpose To evaluate midterm clinical outcomes of monopolar no-touch RFA in single HCCs 2.5 cm or smaller. Materials and Methods In this multicenter clinical trial (ClinicalTrials.gov: NCT03375281), participants were evaluated for eligibility from November 2017 to January 2019. Patients with single HCCs 2.5 cm or smaller planning to be treated with no-touch RFA were enrolled. The rate of successful no-touch RFA, defined as performing RFA without violation of the tumor itself, was recorded. Multivariable logistic regression analysis was used to determine associated factors for failure of no-touch RFA. Development of major complication after no-touch RFA was also recorded. Cumulative incidence of local tumor progression (LTP) and recurrence-free survival were estimated by using the Kaplan-Meier method. Results A total of 140 participants (mean age, 62 years ± 9 [standard deviation]; 106 men) were evaluated. No-touch RFA was successfully performed in 128 participants (128 of 140; 91.4%), and conversion to tumor puncture RFA was undertaken in 12 participants because of the lack of a safe access route. By using either no-touch RFA or conversion to tumor puncture RFA, all participants achieved technical success of RFA, which was defined as complete coverage of target tumor by ablation zone. Insufficient peritumoral parenchyma (<5 mm width around more than half portion of tumor; odds ratio, 74; 95% CI: 18, 309; P < .001) was the only significant predictive factor for failure of the no-touch technique. Among the 140 participants, LTP developed in two participants, and the estimated 1- and 2-year cumulative incidence of LTP was 0.7% and 1.6%, respectively. The estimated 1- and 2-year recurrence-free survival was 82.8% and 74.1%, respectively. Conclusion No-touch radiofrequency ablation was an effective and safe treatment method for small hepatocellular carcinomas (≤2.5 cm), with 1.6% of cumulative incidence of local tumor progression at 2 years. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Soulen and García-Mónaco in this issue.