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The real-world virological efficacy and safety of interferon-free direct-acting antiviral (DAA) therapy with sofosbuvir (SOF) and velpatasvir (VEL) were assessed in hepatitis C virus (HCV) genotype 1- and 2-infected patients with decompensated cirrhosis. A total of 65 patients with HCV-related decompensated cirrhosis (Child-Pugh score of 7 points or more) who were treated with the SOF/VEL regimen were enrolled. The sustained virological response (SVR) rate and safety profile were analyzed. SVR was defined as undetectable serum HCV RNA at 12 weeks after the end of treatment (SVR12). The percentages of patients with undetectable HCV RNA at 4, 8, and 12 weeks after the start of therapy were 81.2% (95% confidence interval [CI], 69.5-89.9) (52/64), 98.4% (95% CI, 91.2-100.0) (60/61), and 98.5% (95% CI, 91.7-100.0) (64/65), respectively. The overall SVR rate was 92.3% (95% CI, 83.0-97.5) (60/65). Albumin-bilirubin (ALBI) scores decreased during and after treatment (p

Alpha-fetoprotein (AFP) response (relative decline in AFP) is associated with imaging response evaluated by response evaluation criteria in solid tumors ver1.1 (RECIST) and survival in treatment for hepatocellular carcinoma (HCC). However, the optimal threshold of AFP response is still unknown, especially in atezolizumab and bevacizumab (Atez/Bev) treatment. In this prospective multicenter study, we aimed to investigate an optimal threshold of AFP response in Atez/Bev treatment. Out of 284 patients with unresectable HCC who were treated with Atez/Bev, 91 patients with AFP ≥ 10 ng/ml were enrolled in the multicenter study. We investigated the relationship between various AFP response thresholds (relative decline ≥ 20%, ≥ 50%, and ≥ 75%) and treatment response and progression-free survival (PFS). An AFP relative decrease of ≥ 50% was associated with an overall response rate (ORR) with an odds ratio (95% confidence interval [CI]) of 5.7 (1.9-17). Disease control rate (DCR) was associated with an AFP relative decrease of ≥ 20%, with a 100% positive predictive value and a 52.0% sensitivity. AFP relative decreases of ≥ 50% and ≥ 20% were significantly associated with PFS with a hazard ratio (HR) of 5.60 (95% CI: 1.6-19, p = 0.006) and a HR of 4.44 (95% CI: 1.9-10, p 0.001), respectively. AFP response of ≥ 50% and ≥ 20% were related to ORR and DCR, respectively, and both of these responses were also associated with PFS. AFP can be used as a real-time monitor during Atez/Bev treatment and is helpful for treatment optimization.

Tumor-agnostic precision medicine employing comprehensive genome profiling (CGP) and using next-generation sequencing (NGS) has been progressing recently. This review focuses on precision medicine for advanced unresectable hepatobiliary and pancreatic cancers. In this paper, for biliary tract cancer (BTC), therapies that target several regulators of cancer cell growth, including isocitrate dehydrogenase 1 (IDH1), fibroblast growth factor receptor 2 (FGFR2) fusion, proto-oncogene B-Raf (BRAF), and human epidermal growth factor receptor 2 (HER2) alterations, are reviewed. For pancreatic ductal adenocarcinoma (PDAC), therapies for Kirsten rat sarcoma virus (KRAS) gene mutation G12C, neuregulin (NRG)1, and breast cancer type 1 and 2 susceptibility (BRCA1/2), gene alterations are summarized. On the other hand, precision medicine targets were not established for hepatocellular carcinoma (HCC), although telomerase reverse transcriptase (TERT), tumor protein P53 (TP53), and Wnt/β catenin signaling alterations have been recognized as HCC driver oncogenes. Tumor-agnostic therapies for microsatellite instability-high (MSI-H) and neurotropic tyrosine receptor kinase (NTRK) fusion cancers effectively treat biliary and pancreatic cancers. Precision medicine methods developed using NGS of circulating tumor DNA (ctDNA) and utilizing a liquid biopsy technique are discussed.

Intrahepatic cholangiocarcinoma (ICC) is frequently driven by aberrant KRAS activation and develops in the liver with chronic inflammation. Although the Notch signaling pathway is critically involved in ICC development, detailed mechanisms of Notch-driven ICC development are still unknown. Here, we use mice whose Notch signaling is genetically engineered to show that the Notch signaling pathway, specifically the Notch/Hes1 axis, plays an essential role in expanding ductular cells in the liver with chronic inflammation or oncogenic Kras activation. Activation of Notch1 enhanced the development of proliferating ductal cells (PDC) in injured livers, while depletion of Hes1 led to suppression. In correlation with PDC expansion, ICC development was also regulated by the Notch/Hes1 axis and suppressed by Hes1 depletion. Lineage-tracing experiments using EpcamcreERT2 mice further confirmed that Hes1 plays a critical role in the induction of PDC and that ICC could originate from PDC. Analysis of human ICC specimens showed PDC in nonneoplastic background tissues, confirming HES1 expression in both PDC and ICC tumor cells. Our findings provide novel direct experimental evidence that Hes1 plays an essential role in the development of ICC via PDC. Significance: This study contributes to the identification of the cells of origin that initiate ICC and suggests that HES1 may represent a therapeutic target in ICC.

Improvements in the hepatocellular carcinoma (HCC) recurrence rate and survival have been frequently reported following virus eradication after hepatitis C virus (HCV)-related HCC cure. However, the efficacy of direct-acting antiviral (DAA) therapy in patients who included those with advanced HCC and decreased hepatic functional reserve is unknown. A comparative examination was retrospectively conducted of 141 patients with hepatitis C who started DAA therapy within 1 year after undergoing curative HCC treatment and showed a sustained viral response (SVR) and 327 patients who underwent curative treatment for HCV-related HCC and did not subsequently receive antiviral therapy. Whether DAA therapy was given was identified as an independent factor related to both HCC recurrence and survival. Both the recurrence and survival rates improved significantly with DAA therapy in Child-Pugh (CP)-A, whereas no difference in the recurrence rate was seen with DAA therapy in CP-B. However, the survival rate was significantly higher in the DAA group in this class. Similarly, dividing the patients by the Milan criteria showed significant improvements in the recurrence rate and survival with DAA therapy in patients within the Milan criteria. Patients with HCC beyond the Milan criteria showed no difference in recurrence rates, but the DAA group tended to have higher survival rates. Thus, DAA after curative therapy for HCC can be expected to improve survival in patients with advanced HCC or decreased hepatic functional reserve. HCV should be aggressively eradicated in all patients eligible for curative treatment of HCC.

Magnifying narrow-band imaging (M-NBI) has recently improved the accuracy of endoscopic diagnosis of gastrointestinal tumors, including colorectal polyps. However, it can be difficult to distinguish between sessile serrated adenoma/polyps (SSA/Ps) and other polyps, especially hyperplastic polyps (HPs), by histological biopsy, because diagnostic features of SSA/Ps can be detected around the colon crypt bases. We aimed to evaluate the accuracy of endoscopic diagnosis of SSA/Ps using M-NBI compared with histological biopsy.We prospectively enrolled patients diagnosed with SSA/Ps by preoperative endoscopy and assessed the diagnostic accuracy. The primary outcome was the diagnostic accuracy of endoscopy and biopsy.Between August 2015 and October 2017, 295 lesions were resected by polypectomy or endoscopic mucosal resection, and 79 endoscopically resected specimens that were endoscopically diagnosed as SSA/P underwent biopsy for histological examination. Two lesions were excluded because the specimens were too small for histological examination. Finally, 77 endoscopically resected specimens and 77 biopsy specimens were included in the analysis. Histopathological examination showed 67 SSA/Ps, 8 HPs, and 2 adenomas. The sensitivity, specificity and accuracy of endoscopic M-NBI diagnosis for SSA/Ps were 95.7%, 95.5% and 95.6%, respectively. The sensitivity, specificity and accuracy of histological diagnosis of a single biopsy specimen were 71.6%, 90.0% and 74.0%, respectively. The McNemar test showed significant differences between biopsy and endoscopy diagnoses (P=0.001).This study shows that biopsy may be avoided by using M-NBI in patients with suspected SSA/Ps.

Chronic inflammation is accompanied by recurring cycles of tissue destruction and repair and is associated with an increased risk of cancer1–3. However, how such cycles affect the clonal composition of tissues, particularly in terms of cancer development, remains unknown. Here we show that in patients with ulcerative colitis, the inflamed intestine undergoes widespread remodelling by pervasive clones, many of which are positively selected by acquiring mutations that commonly involve the NFKBIZ, TRAF3IP2, ZC3H12A, PIGR and HNRNPF genes and are implicated in the downregulation of IL-17 and other pro-inflammatory signals. Mutational profiles vary substantially between colitis-associated cancer and non-dysplastic tissues in ulcerative colitis, which indicates that there are distinct mechanisms of positive selection in both tissues. In particular, mutations in NFKBIZ are highly prevalent in the epithelium of patients with ulcerative colitis but rarely found in both sporadic and colitis-associated cancer, indicating that NFKBIZ-mutant cells are selected against during colorectal carcinogenesis. In further support of this negative selection, we found that tumour formation was significantly attenuated in Nfkbiz-mutant mice and cell competition was compromised by disruption of NFKBIZ in human colorectal cancer cells. Our results highlight common and discrete mechanisms of clonal selection in inflammatory tissues, which reveal unexpected cancer vulnerabilities that could potentially be exploited for therapeutics in colorectal cancer. In patients with ulcerative colitis, chronic inflammation can lead to remodelling of the colorectal epithelium through positive selection of clones with mutations in genes related to IL-17 signalling, which, however, might be negatively selected during colitis-associated carcinogenesis.

Background It is unclear whether the fibrosis 4 index (FIB-4), a marker of liver fibrosis, at baseline and change in FIB-4 after sustained virological response (SVR) is associated with incident hepatocellular carcinoma (HCC) risk. In this study, we examined the association of incident HCC risk with baseline FIB-4 and sustained high FIB-4 (>3.25) at any time point after SVR. Methods A total of 3823 patients who received direct-acting antiviral treatment and achieved SVR were enrolled. The FIB-4 was measured 24 weeks after the end of direct-acting antiviral treatment and achievement of SVR (SVR24), and 1, 2, and 3 years after SVR24, after which subsequent HCC development was investigated. Results In patients with an FIB-4 >3.25 at SVR24 and 1, 2, and 3 years after SVR24, subsequent HCC development was significantly higher than in those with an FIB-4 ≤3.25 at each point. The rates of HCC development 1, 2, 3, and 4 years after SVR24 were significantly higher in patients with sustained FIB-4 >3.25 than in those whose FIB-4 decreased to ≤3.25 (5.4%, 9.2%, 11.7%, and 16.0%, respectively, vs 2.2%, 3.1%, 3.7%, and 4.4%; P 3.25 at SVR24 and 1, 2, and 3 years later were 3.38 (2.4–4.8), 2.95 (1.9–4.7), 2.62 (1.3–5.1), and 3.37 (1.4–9.8), respectively. Conclusions The FIB-4 could be used to assess HCC development risk at any time after SVR, and changes in FIB-4 were associated with changes in the HCC development risk. Repeated assessments of FIB-4 could serve as a prognostic indicator of a high-risk HCC cohort that may require more intensive HCC surveillance strategy.

Recently, underwater endoscopic mucosal resection (UEMR) without submucosal injection was introduced as a new replacement for conventional EMR (CEMR) and was reported to be useful for resecting large colonic polyps. Here, we aimed to assess the efficacy and safety of these two methods by a systematic review and meta-analysis. We comprehensively searched multiple databases until July 2021 to identify randomized controlled trials (RCTs) comparing UEMR with CEMR. The primary outcomes were the proportion of R0 resection and mean procedure time, and the secondary outcomes were the proportion of en bloc resection and all adverse events. Three reviewers independently searched for articles, extracted data, and assessed the risk of bias. We evaluated the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach. This study was registered in www.protocols.io (Protocol Integer ID: 40849). We included six RCTs (1,374 polyps). We judged that a meta-analysis was not available, and the data were summarized narratively for the proportion of R0 resection. Regarding procedure time, UEMR likely resulted in a large reduction (mean difference = -64.3 seconds; 95% confidence interval (CI) = -122.5 to -6.0 seconds; I2 = 86%; moderate certainty of evidence). UEMR likely resulted in a large increase in en bloc resection (odds ratio = 1.85; 95% CI = 1.15 to 2.98; I2 = 60%; moderate certainty of evidence). Percentages of adverse events were 0-17% with CEMR and 0-16% with UEMR. In summary, UEMR might have higher efficacy than CEMR in the endoscopic resection of nonpedunculated colorectal polyps, with likely a large reduction in procedure time.

Recent innovations in the next-generation sequencing technologies have unveiled that the accumulation of genetic alterations results in the transformation of normal cells into cancer cells. Accurate and timely repair of DNA is, therefore, essential for maintaining genetic stability. Among various DNA repair pathways, the mismatch repair (MMR) pathway plays a pivotal role. MMR deficiency leads to a molecular feature of microsatellite instability (MSI) and predisposes to cancer. Recent studies revealed that MSI-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, regardless of their primary site, have a promising response to immune checkpoint inhibitors (ICIs), leading to the approval of the anti-programmed cell death protein 1 monoclonal antibody pembrolizumab for the treatment of advanced or recurrent MSI-H/dMMR solid tumors that continue to progress after conventional chemotherapies. This new indication marks a paradigm shift in the therapeutic strategy of cancers; however, when considering the optimum indication for ICIs and their safe and effective usage, it is important for clinicians to understand the genetic and immunologic features of each tumor. In this review, we describe the molecular basis of the MMR pathway, diagnostics of MSI status, and the clinical importance of MSI status and the tumor mutation burden in developing therapeutic strategies against gastrointestinal and hepatobiliary malignancies.

Background: Lenvatinib (LEN) has been approved for patients with unresectable hepatocellular carcinoma (u-HCC) since March 2018 in Japan. We performed a retrospective nationwide multicenter study to clarify the clinical characteristics of LEN in real-world practice. Methods: A total of 343 u-HCC patients who received LEN from March 2018 to May 2020 at 23 sites in Japan were registered. Results: During the median observation period of 10.5 months, 143 patients died. In Child-Pugh A (n = 276) and Child-Pugh B (n = 67) patients, the median overall survival (OS) was 21.0 and 9.0 months. The median progression-free survival (PFS) was 8.8 months in Child-Pugh A patients. The objective response rate (ORR) and disease control rate (DCR) according to modified response evaluation criteria in solid tumors (RECIST criteria) were 42.1% and 82.1%. The independent pretreatment factors associated with mortality in all patients were AFP ≥ 400 ng/mL (hazard ratio (HR) 2.00, 95% confidential interval (95% CI) 1.08–2.09, p &lt, 0.0001), modified albumin-bilirubin (ALBI) grade 2b or 3 (HR 1.56, 95% CI 1.09–2.17, p = 0.012), major vascular invasion (HR 1.91, 95% CI 1.26–2.89, p = 0.0022), PS &gt, 0 (HR 1.50, 95% CI 1.09–2.08, p = 0.014), and MTT (molecular targeted therapy) experience (HR 2.22, 95% CI 1.56–3.13, p = 0.00038). In the MTT naïve patients with ALBI grade 1 or modified ALBI 2a and BCLC stage B (n = 68), median OS and PFS were 25.3 and 12.3 months. Liver-related adverse events during LEN were the only significant adverse event associated with OS (HR 2.74, 95% CI 1.93–3.88, p &lt, 0.0001). Among the Child-Pugh A patients with extrahepatic metastasis and no major vascular invasion, median PFS in the patients with bone metastasis was significantly shorter than those with lung or adrenal grand metastasis (6.3 vs. 12.5 months, p = 0.0025). Conclusion: LEN showed a high response rate in real-world practice. Pretreatment factors, including ALBI score, AFP, and major vascular invasion are important in making a treatment strategy for patients with u-HCC. The patients with bone metastasis would be candidates for new therapeutic approaches.

Activation-induced cytidine deaminase (AID) encoded by the Aicda gene initiates class-switch recombination and somatic hypermutation of immunoglobulin genes. In addition to this function, AID is also implicated in the epigenetic regulation in pluripotent stem cells and in the oncogenesis of lymphoid and non-lymphoid origins. To examine AID’s role in specific cell types, we developed mouse strains of conditional knockout (Aicda-FL) and knock-in with a red fluorescent protein gene (RFP) inserted into the Aicda locus (Aicda-RFP). These two strains were obtained from a single targeting event in embryonic stem cells by a three-loxP or tri-lox strategy. Partial and complete recombination among the three loxP sites in the Aicda-RFP locus gave rise to Aicda-FL and AID-deficient loci (Aicda-KO), respectively, after mating Aicda-RFP mice with Cre-expressing mice driven by tissue-non-specific alkaline phosphate promoter. We confirmed RFP expression in B cells of germinal centers of intestine-associated lymphoid tissue. Mice homozygous for each allele were obtained and were checked for AID activity by class-switch and hypermutation assays. AID activity was normal for Aicda-FL but partially and completely absent for Aicda-RFP and Aicda-KO, respectively. Aicda-FL and Aicda-RFP mice would be useful for studying AID function in subpopulations of B cells and in non-lymphoid cells.

Most hepatocellular carcinomas (HCCs) develop on the basis of chronic hepatitis, but the mechanism of epigenetic regulation in inflammatory hepatocarcinogenesis has yet to be elucidated. Among de novo DNA methyltransferases (DNMTs), DNMT3B has lately been reported to act specifically on actively transcribed genes, suggesting the possibility that it plays a role in the pathogenesis of cancer. We confirmed that DNMT3B isoforms lacking its catalytic domain were highly expressed in HCCs compared with non-tumorous liver tissue. To elucidate the role of DNMT3B in hepatocarcinogenesis, we generated a genetically engineered mouse model with hepatocyte-specific Dnmt3b deletion. The liver of the Dnmt3b-deficient mice exhibited an exacerbation of thioacetamide-induced hepatitis, progression of liver fibrosis and a higher incidence of HCC compared with the liver of the control mice. Whole-genome bisulfite sequencing verified a lower CG methylation level in the Dnmt3b-deficient liver, demonstrating differentially methylated regions throughout the genome. Transcriptome analysis revealed decreased expression of genes related to oxidative phosphorylation in the Dnmt3b-deficient liver. Moreover, primary hepatocytes isolated from the Dnmt3b-deficient mice showed reduced mitochondrial respiratory capacity, leading to the enhancement of oxidative stress in the liver tissue. Our findings suggest the protective role of DNMT3B against chronic inflammation and HCC development via maintaining mitochondrial homeostasis.

Hepatocellular carcinoma (HCC) developing after hepatitis C virus (HCV) eradication is a serious clinical concern. However, molecular basis for the hepatocarcinogenesis after sustained virologic response (SVR) remains unclear. In this study, we aimed to unveil the transcriptomic profile of post-SVR liver tissues and explore the molecules associated with post-SVR carcinogenesis. We analysed 90 RNA sequencing datasets, consisting of non-cancerous liver tissues including 20 post-SVR, 40 HCV-positive and 7 normal livers, along with Huh7 cell line specimens before and after HCV infection and eradication. Comparative analysis demonstrated that cell cycle- and mitochondrial function-associated pathways were altered only in HCV-positive non-cancerous liver tissues, whereas some cancer-related pathways were up-regulated in the non-cancerous liver tissues of both post-SVR and HCV-positive cases. The persistent up-regulation of carcinogenesis-associated gene clusters after viral clearance was reconfirmed through in vitro experiments, of which, CYR61, associated with liver fibrosis and carcinogenesis in several cancer types, was the top enriched gene and co-expressed with cell proliferation-associated gene modules. To evaluate whether this molecule could be a predictor of hepatocarcinogenesis after cure of HCV infection, we also examined 127 sera from independent HCV-positive cohorts treated with direct-acting antivirals (DAAs), including 60 post-SVR-HCC patients, and found that the elevated serum Cyr61 was significantly associated with early carcinogenesis after receiving DAA therapy. In conclusion, some oncogenic transcriptomic profiles are sustained in liver tissues after HCV eradication, which might be a molecular basis for the liver cancer development even after viral clearance. Among them, up-regulated CYR61 could be a possible biomarker for post-SVR-HCC.

A 67-year-old man diagnosed with clinical Stage Ⅳ gastric cancer was administered nivolumab as fourth-line chemotherapy. After 9 courses, he was emergently admitted with complaints of low blood pressure and general malaise. On the fourth hospital day, he had high-grade fever and elevated serum C-reactive protein. Computed tomography showed a moderate amount of pericardial effusion. He was administered 1.7 mg/kg of methylprednisolone and improved rapidly. A hormonal blood examination showed his adrenal gland disorder. This is the first case in our country of pericardial effusion as an immune-reactive adverse event, which is not well known in Japan.

Nucleos(t)ide analogs (NA) suppress hepatitis B virus (HBV) replication and reduce the risk of hepatocellular carcinoma (HCC). However, NA cannot suppress carcinogenesis completely in patients with chronic hepatitis B. The aims of this study were to identify risk factors for HCC and develop a refined carcinogenesis prediction model. Patients receiving NA therapy (n = 1,183) were recruited retrospectively from the 16 hospitals. All patients had been receiving NA continuously for more than 1 year until the end of the follow-up. During a median follow-up of 4.9 (1.0–12.9) years, 52 (4.4%) patients developed HCC. A multivariate analysis revealed that male gender, older age, lower platelet counts at the baseline, and detectable HBV DNA during NA therapy were independent predictive factors of HCC development. The PAGE-B score was calculated by using these factors. 240 (20.3%), 661 (55.9%), and 282 (23.8%) patients were classified into low-, intermediate-, and high-risk groups, respectively. In the intermediate- and high-risk group, detectable HBV DNA was significantly associated with a higher risk of HCC development compared with continuously undetectable HBV DNA, respectively (HR 3.338; 95% CI 1.045–10.66/HR 3.191; 95% CI 1.543–6.597). PAGE-B–DNA, which is the combined PAGE-B and HBV DNA status, was valuable for a more refined stratification of PAGE-B.

Recent genetic analyses revealed genetic heterogeneity in hepatocellular carcinoma (HCC), although it remains unclear how genetic alterations contribute to the multistage progression of HCC, especially the early step from hypovascular liver nodules to hypervascular HCC. We conducted multiregional whole-genome sequencing on HCCs with a nodule-in-nodule appearance, consisting of inner hypervascular HCC surrounded by hypovascular HCC arising from a common origin, and identified point mutations, structural variations, and copy-number variations in each specimen. According to the genetic landscape of the inner and outer regions, together with the pathological and radiological findings, we examined the stepwise evolution of cancer cells from slow-growing HCC to rapid-growing HCC. We first demonstrated that most tumor cells consisting of hypovascular well-differentiated HCCs already harbored thousands of point mutations and even several structural variations, including chromosomal translocations and chromothripsis, as the trunk events. Telomerase reverse transcriptase (TERT)-associated aberrations, including promoter mutations, chromosomal translocation, and hepatitis B virus DNA integration, as well as abnormal methylation status, were commonly detected as the trunk aberrations, while various liver cancer-related genes, which differed in each case, had additionally accumulated in the inner dedifferentiated nodules. Further, differences in the trunk and branch mutational signatures suggested a multistep contribution to the mutagenesis in each case. In conclusion, genomic alterations associated with the TERT gene could be the key driver events to form the hypovascular HCC, and additional case-specific driver mutations accumulate during the progression phase, forming intra- and inter-tumoral heterogeneity, confirming the importance of genetic testing before targeting therapy. These data shed light on the process of multistep hepatocarcinogenesis and will be helpful toward investigating new therapeutic strategies for HCC. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Although several targeted therapy agents are available for advanced HCC, their antitumor efficacy remains limited. As the complex genetic landscape of HCC would compromise the antitumor efficacy of targeted therapy, a deeper understanding of the genetic landscape of hepatocarcinogenesis is necessary. Recent comprehensive genetic analyses have revealed the driver genes of HCC, which accumulate during the multistage process of hepatocarcinogenesis, facilitating HCC genetic heterogeneity. In addition, as early genetic changes may represent key therapeutic targets, the genetic landscapes of early HCC and precancerous liver tissues have been characterized in recent years, in parallel with the advancement of next-generation sequencing analysis. In this review article, we first summarize the landscape of the liver cancer genome and its intratumor heterogeneity. We then introduce recent insight on early genetic alterations in hepatocarcinogenesis, especially those in early HCC and noncancerous liver tissues. Finally, we summarize the multistep accumulation of genetic aberrations throughout cancer progression and discuss the future perspective towards the clinical application of this genetic information.

Background & Aims We aimed to clarify the features of resistance-associated substitutions (RASs) after failure of multiple interferon (IFN)-free regimens in HCV genotype 1b infections. Methods A total of 1,193 patients with HCV for whom direct-acting antiviral (DAA) treatment had failed were enrolled from 67 institutions in Japan. The RASs in non-structural protein (NS)3, NS5A, and NS5B were determined by population sequencing. Results Failure of 1, 2, and 3 regimens was observed in 1,101; 80; and 12 patients, respectively. Among patients with failure of 1 regimen, Y56H and D168V in NS3 were more frequently detected after failure of paritaprevir, whereas D168E was more frequently detected after failure of regimens including asunaprevir. R30H and L31-RAS in NS5A were frequently detected after failure of regimens including daclatasvir. The prevalence of Y93-RAS was high irrespective of the regimen. S282T RAS in NS5B was detected in 3.9% of ledipasvir/sofosbuvir failures. The prevalence of D168-RAS increased significantly according to the number of failed regimens (p, Graphical abstract, Highlights • Multiple direct-acting antiviral regimen failures may generate multiple RASs. • Prevalence of RASs increased according to the number of failed regimens. • These mutations contribute to viral resistance to multiple treatment regimens. • These mutations must be considered in decision making of chronic hepatitis C treatment.

Abatacept, a cytotoxic T lymphocyte antigen-4 immunoglobulin recombinant fusion protein, is an immunosuppressive agent indicated for rheumatoid arthritis. Although no significant increase in malignancy has been reported in abatacept-treated patients, whether or not abatacept accelerates tumor progression in specific cancer types remains unclear. We herein report a 66-year-old woman who showed unusually rapid progression of hepatocellular carcinoma following abatacept therapy for rheumatoid arthritis. Abatacept was speculated to have accelerated her hepatocellular carcinoma progression in the setting of her preexisting risk factors: autoimmune hepatitis and long-term methotrexate use. We propose close tumor surveillance be performed during abatacept therapy, especially for high-risk patients.

Aim In cases of symptomatic giant hepatic cysts, appropriate treatment is required to relieve symptoms. Ethanol, minocycline hydrochloride, and ethanolamine oleate have been conventionally used for ultrasound (US)-guided sclerotherapy. However, liquid sclerosing agents could mix with the residual fluid in the cyst and reduce their sclerotic effects. We carried out US-guided microfoam sclerotherapy using polidocanol for three patients and evaluated its efficacy and safety. Methods Between May 2016 and March 2017, three female patients with symptomatic giant hepatic cysts were referred to our hospital. All of them were prospectively included in this study. Results The maximum diameters of the hepatic cysts in the three patients were 92 × 89 × 86 mm, 155 × 119 × 140 mm, and 223 × 195 × 123 mm, respectively. Polidocanol microfoam was successfully administered through an 8.5-Fr pigtail catheter for all patients. One, two, and three microfoam sclerotherapy sessions were undertaken according to the initial cyst volume for cases 1, 2, and 3, respectively. The mean reduction rates of the cyst volume were 90.1% (85.5-98.9%) at 3 months, 96.3% (91.9-99.9%) at 6 months, and 99.5% (99.1-99.9%) at 9 months after treatment. No significant treatment-induced adverse effects were observed. Conclusion Ultrasound-guided microfoam sclerotherapy using polidocanol could be an effective and safe method for the treatment of symptomatic giant liver cysts.

Chronic gastritis caused by Helicobacter pylori (H. pylori) infection could lead to the development of gastric cancer. The finding that multiple gastric cancers can develop synchronously and/or metachronously suggests the development of field cancerization in chronically inflamed, H. pylori-infected gastric mucosa. The genetic basis of multiple tumorigenesis in the inflamed stomach, however, is not well understood. In this study, we analyzed the microsatellite instability (MSI) status and copy number aberrations (CNAs) of 41 multiple intramucosal early gastric cancers that synchronously or metachronously developed in 19 patients with H. pylori infection. Among the 41 intramucosal gastric carcinomas, 9 (22%) exhibited MSI, and the remaining 32 (78%) exhibited the microsatellite stable (MSS) phenotype. Metachronous multiple intramucosal gastric carcinoma exhibit inter-tumor heterogeneity by individually acquiring genetic aberrations. All synchronous multiple intramucosal gastric carcinoma pairs shared a common MSI/MSS profile, and CNA analysis revealed that synchronous multiple intramucosal gastric carcinoma pairs with the MSS phenotype shared common aberrations of representative tumor-suppressor genes, including focal deletion of APC, TP53, CDKN2A, and CDKN2B. Multiregional CNA analysis revealed that heterogeneous gene amplifications/deletions, including PDL1 amplification, evolved under the presence of shared "trunk" genetic alterations in a subpopulation of individual intramucosal gastric carcinomas. These data suggest that multiple gastric carcinomas develop in a multicentric/multifocal manner exhibiting features of inter- and intra-tumor heterogeneity in H. pylori-infected gastric mucosa, whereas synchronous multiple intramucosal gastric carcinomas could share partially common genetic alterations, possibly via common oncogenic pathways.

Systemic chemotherapy using a multitargeted tyrosine kinase inhibitor is an established treatment for advanced-stage tumors in various organs. Comprehensive genomic analyses using next-generation sequencing technology revealed the intra- and intertumor heterogeneity of human hepatocellular carcinomas (HCCs), and provided evidence for the use of therapeutic agents effective against multiple targets in tumor cells. Recently, the efficacy and safety of a multitargeted tyrosine kinase inhibitor, lenvatinib, was confirmed by a randomized global phase III trial; thus, lenvatinib was approved as first-line therapy for HCC, providing a new therapeutic option for patients at an advanced stage. In this article, we introduce the application of molecular targeted therapy using lenvatinib and discuss future aspects of therapeutic options for advanced HCC.

BACKGROUND AND AIM Mac-2-binding protein glycosylation isomer (M2BPGi) was recently identified as a serum glycobiomarker for liver fibrosis. However, the relationship between M2BPGi and malnutrition in patients with chronic liver disease (CLD) is unknown. We aimed to evaluate whether M2BPGi could be a surrogate marker for malnutrition in patients with CLD. METHODS In total, 338 outpatients with CLD were enrolled (median age: 67 years). We evaluated the associations among liver fibrosis markers (M2BPGi, fibrosis-4 index, and aspartate aminotransferase-to-platelet count ratio index), Child-Pugh stages, and nutritional status markers. RESULTS The median value (range) of serum M2BPGi levels was 0.94 cut-off index (COI) (0.22-11.57) in chronic hepatitis and Child-Pugh A (n = 274), 4.775 COI (1.32-16.68) in Child-Pugh B (n = 46), and 11.37 COI (6.03-18.33) in Child-Pugh C (n = 18) (overall significance, P

Hepatocellular carcinoma (HCC) originates from regenerating liver cells with genetic alterations in chronically inflamed liver. Ductal cells and hepatocytes proliferate for liver regeneration, and proliferating ductal cells (PDC) derived from bile ductules have long been considered putative liver stem/progenitor cells and candidate cellular origins of HCC. The potential of PDC as tumor-originating cells, however, remains controversial in contrast to accumulating evidence that HCC originates from hepatocytes. Here, we demonstrate that PDCs expressing the established surface and cancer stem cell marker EpCAM give rise to HCC in inflamed liver. EpCAM-expressing PDCs were specifically labeled in newly developed EpcamCreERT2 mice and traced in a chemically induced liver injury model. Stepwise accumulation of genetic alterations in EpCAM-positive cells was induced by the mutagenesis activity of activation-induced cytidine deaminase using conditional transgenic mice. Lineage-tracing experiments revealed that labeled PDC differentiated into cholangiocytes, but not into hepatocytes, in the chemically damaged liver. Nevertheless, EpCAM-positive PDC with genetic alterations gave rise to HCC after 8 months of chemical administration. PDC-derived HCC showed histologic characteristics of concomitant ductule-like structures resembling human cholangiolocellular carcinoma (CLC) and exhibited serial transitions from PDC-like CLC cells to hepatocyte-like HCC cells. The Wnt signaling pathway was specifically upregulated in the CLC components of PDC-derived HCC. Our findings provide direct experimental evidence that EpCAM-expressing PDC could be a cellular origin of HCC, suggesting the existence of stem/progenitor-derived hepatocarcinogenesis. Cancer Res; 77(22); 6131–43. ©2017 AACR.

Hepatitis B virus (HBV) infection evokes host immune responses that primarily determine the outcome of HBV infection and the clinical features of HBV-associated liver disease. The precise mechanisms by which host factors restrict HBV replication, however, are poorly understood due to the lack of useful animal models that recapitulate immune responses to HBV. Here, we performed comprehensive immunologic gene expression profiling of the liver of a mouse model recapitulating anti-HBV immune response using a high sensitivity direct digital counting system. Anti-HBV cellular immunity with liver inflammation was elicited in mice hydrodynamically injected with a CpG-depleted plasmid encoding hepatitis B surface antigen (HBsAg) gene after preimmunization with HBsAg vaccine. Comprehensive expression analyses revealed the upregulation of Th1-associated genes including tumor necrosis factor (Tnf) and negative regulators of T cell function in the inflamed liver. Interestingly, activation-induced cytidine deaminase (Aicda, termed AID in humans), which reportedly suppresses HBV infection in vitro, was upregulated in hepatocytes in the course of anti-HBV immunity. Hepatocytic expression of Aicda in a Tnf-dependent manner was confirmed by the administration of Tnf antagonist into Aicda-tdTomato mice with anti-HBV immunity. Our findings suggest that activation of Tnf-Aicda axis and co-inhibitory signals to T cells in coordination with Th1-type immunity has critical roles in the immune response against HBV infection.

Transarterial chemoembolization (TACE) is the recommended first-line treatment for intermediate-stage hepatocellular carcinoma (HCC). In patients who became refractory to TACE, a treatment switch to tyrosine kinase inhibitors (TKIs) needs to be considered. However, TACE could worsen liver function, thereby narrowing the time window for a switch to TKIs because TKIs are recommended for patients with Child-Pugh grade A (CP-A). We investigated the factors associated with CP grade deterioration after TACE. Among patients who underwent TACE, 125 patients with CP-A were enrolled. The cumulative CP grade deterioration rates were 20.3%, 27.1%, and 41.4% at six months, one year, and two years, respectively. Multivariate analysis revealed that factors associated with CP grade deterioration included high Mac-2 binding protein glycosylation isomer (M2BPGi) levels (&gt, 2.00 cut-off index) and beyond the up-to-seven criteria. The cumulative CP grade deterioration rates of patients with high M2BPGi and beyond the up-to-seven criteria were 50.6% and 59.2% at six months and one year, respectively, which were significantly higher than for those in any other groups. The combination of M2BPGi and up-to-seven criteria could be a surrogate marker for predicting CP grade deterioration after TACE. In patients with intermediate-stage HCC, elevated M2BPGi levels, and beyond the up-to-seven criteria, an early treatment switch to TKIs should be considered to improve their prognosis.

HBV reactivation could be induced under immunosuppressive conditions in patients with resolved infection. This study aimed to clarify the viral factors associated with the pathogenesis of HBV reactivation in association with the immunosuppressive status. Whole HBV genome sequences were determined from the sera of 24 patients with HBV reactivation, including 8 cases under strong immunosuppression mediated by hematopoietic stem cell transplantation (HSCT) and 16 cases without HSCT. Ultra-deep sequencing revealed that the prevalence of genotype B and the ratio of non-synonymous to synonymous evolutionary changes in the surface (S) gene were significantly higher in non-HSCT cases than in patients with HSCT. Those non-synonymous variants included immune escape (6/16 cases) and MHC class II-restricted T-cell epitope variants (6/16 cases). Furthermore, reactivated HBV in 11 of 16 (69%) non-HSCT cases possessed substitutions associated with impaired virion secretion, including E2G, L77R, L98V, T118K, and Q129H in the S region, and M1I/V in the PreS2 region. In conclusion, virologic features of reactivated HBV clones differed depending on the intensity of the immunosuppressive condition. HBV reactivation triggered by immunosuppressive conditions, especially those without HSCT, was characterized by the expansion of variants associated with immune escape, MHC class II-restricted T-cell epitope alterations, and/or impaired virion secretion.

Hepatocellular carcinoma (HCC) recurrently develops in cirrhotic liver containing a number of regenerative nodules (RNs). However, the biological tumorigenic potential of RNs is still unclear. To uncover the molecular bases of tumorigenesis in liver cirrhosis, we investigated the genetic aberrations in RNs of cirrhotic tissues using next-generation sequencing. We isolated 205 RNs and 7 HCC tissues from the whole explanted livers of 10 randomly selected patients who had undergone living-donor liver transplantation. Whole-exome sequencing and additional targeted deep sequencing on 30 selected HCC-related genes were conducted to reveal the mutational landscape of RNs and HCCs. Whole-exome sequencing demonstrated that RNs frequently harbored relatively high-abundance genetic alterations, suggesting a clonal structure of each RN in cirrhotic liver. The mutation signature observed in RNs was similar to those determined in HCC, characterized by a predominance of C>T transitions, followed by T>C and C>A mutations. Targeted deep sequencing analyses of RNs identified nonsynonymous low-abundance mutations in various tumor-related genes, including TP53 and ARID1A. In contrast, TERT promoter mutations were not detected in any of the RNs examined. Consistently, TERT expression levels in RNs were comparable to those in normal livers, whereas every HCC tissue demonstrated an elevated level of TERT expression. Analyses of RNs constructing cirrhotic liver indicated that a variety of genetic aberrations accumulate in the cirrhotic liver before the development of clinically and histologically overt HCC. These aberrations in RNs could provide the basis of tumorigenesis in patients with liver cirrhosis.

Background/Aims: Direct-acting antiviral agents (DAAs) have increased the sustained viral response rate with minimal adverse effects and short treatment duration. In addition, recent data suggest the possibility that hepatitis C virus (HCV) clearance results in rapid improvement in metabolic pathways. The aim of the present study was to evaluate whether the DAA treatment without ribavirin lowers hemoglobin A1c (HbA1c) at 12 weeks after therapy completion. Methods: We performed an observational study to assess the effect of sofosbuvir and ledipasvir (SOF/LED) treatment on glycemic control. We compared HbA1c levels before and after treatment with SOF/LED, considering that anemia is not a side effect of these drugs. Results: In the 36 patients with HCV eradication, HbA1c levels decreased significantly after treatment (pre-treatment 5.85% vs. post-treatment 5.65%, p < 0.01). Conclusion: This pilot study shows the possibility that HCV eradication by SOF/LED was accompanied by an improvement of glucose metabolism in the population with or without diabetes, and suggests further investigation.

548 Background: Lenvatinib (LEN) has been used in patients with unresectable hepatocellular carcinoma (u-HCC) since Mar 2018 in Japan. We conducted a nationwide multicenter study and especially focused on the efficacy and safety in the patients with intermediate-stage u-HCC. Methods: A total of 240 patients received LEN from March 2018 at 15 sites in Japan was enrolled. Tumour assessments in accordance with modified RECIST were done using dynamic CT or MRI within 4-8 weeks and every 6-8 weeks thereafter. Results: In this study, 88 of 240 (36.7%) patients were BCLC stage B. Among them 76 (86.3%) patients received TACE before LEN and the median number of TACE was 2 (1-10). Only 4 patients were TKI experienced and other 84 (95.5%) patients received LEN as a 1st line therapy. The median pretreatment ALBI score was -2.35 and 75 (85.2%) patients were Child-Pugh A. In this cohort, 73 (83.0%) patients were beyond up-to-seven criteria and the median pretreatment AFP was 38.2 (2-12870) ng/mL. The median observation time was 8.5 months and 16 patients died. The median progression free survival was 8.7 months, and the median overall survival (OS) was not reached. Objective response rate (ORR) and disease control rate (DCR) were 48.5% and 80.3%. AFP decrease ( > 20%) after 1 month was observed in 52 (59.0%) patients. Child-Pugh B patients (n = 13) had significantly shorter OS than Child-Pugh A (p = 0.02) and median OS in Child-Pugh B patients was 8.8 months. The patients received > 6 times TACE before LEN had significantly shorter OS than patients received ≤ 6 times TACE (p = 0.02). Additional TACE was performed in 8 patients and The median time of restarting LEN was 19 days. The median ALBI score before additional TACE, Day 1 after TACE and Day 28 after TACE were -2.38, -2.07, and -2.36.There was no severe adverse event associated with additional TACE. The median duration of LEN in patients treated with LEN and additional TACE was 8.5 months. Conclusions: The ORR and DCR of LEN in Child-Pugh A patients with intermediate-stage HCC were 46.6% and 79.3%. The therapeutic strategies for intermediate-stage HCC should be discussed based on the liver function, tumor states, and treatment course about TACE.

Helicobacter pylori, a pathogen of various gastric diseases, has many genome sequence variants. Thus, the pathogenesis and infection mechanisms of the H. pylori-driven gastric diseases have not been elucidated. Here, we carried out a large-scale proteome analysis to profile the heterogeneity of the proteome expression of 7 H. pylori strains by using an LC/MS/MS-based proteomics approach combined with a customized database consisting of nonredundant tryptic peptide sequences derived from full genome sequences of 52 H. pylori strains. The nonredundant peptide database enabled us to identify more peptides in the database search of MS/MS data compared with a simply merged protein database. Using this approach, we carried out proteome analysis of genome-unknown strains of H. pylori at as large a scale as genome-known ones. Clustering of the H. pylori strains using proteome profiling slightly differed from the genome profiling and more clearly divided the strains into two groups based on the isolated area. Furthermore, we identified phosphorylated proteins and sites of the H. pylori strains and obtained the phosphorylation motifs located in the N-terminus that are commonly observed in bacteria.

Prophylactic measures are used to reduce DNHB after HBsAg-negative patients receive anti-HBc-positive liver grafts. This study investigated the incidence of DNHB and clinical outcomes in pediatric LT recipients under HBIG prophylaxis, with or without hepatitis B vaccination. Between 1995 and 2013, 51 HBsAg-negative pediatric recipients underwent living-donor LT from anti-HBc-positive donors. The median (range) age was 4 (0.1-17) years, 23 (45%) were male, and 71% were negative for both anti-HBc and anti-HBc. During a median follow-up of 12.1 (0.06-19.9) years, 13 (25.4%) developed DNHB; 7 of the 13 achieved HBsAg seroconversion after administration of LAM or ETV. Among studied patients, 20 (39%) received hepatitis B vaccination, and 2 of them (10%) developed DNHB. At last follow-up, 41% (21/51) discontinued HBIG either after successful HBV vaccination (n = 17) or retransplantation with anti-HBc-negative grafts (n = 4). In conclusion, pediatric LT recipients of anti-HBc-positive grafts, most of them were naive to HBV infection, were at high risk of DNHB, and consistent monitoring for the early detection of DNHB was necessary. A combination use of post-LT vaccination is promising prophylactic strategy against DNHB.

In cases of symptomatic giant hepatic cysts, appropriate treatment is required to relieve symptoms. Ethanol, minocycline hydrochloride, and ethanolamine oleate have been conventionally used for ultrasound (US)-guided sclerotherapy. However, liquid sclerosing agents could mix with the residual fluid in the cyst and reduce their sclerotic effects. We carried out US-guided microfoam sclerotherapy using polidocanol for three patients and evaluated its efficacy and safety.Between May 2016 and March 2017, three female patients with symptomatic giant hepatic cysts were referred to our hospital. All of them were prospectively included in this study.The maximum diameters of the hepatic cysts in the three patients were 92 × 89 × 86 mm, 155 × 119 × 140 mm, and 223 × 195 × 123 mm, respectively. Polidocanol microfoam was successfully administered through an 8.5-Fr pigtail catheter for all patients. One, two, and three microfoam sclerotherapy sessions were undertaken according to the initial cyst volume for cases 1, 2, and 3, respectively. The mean reduction rates of the cyst volume were 90.1% (85.5-98.9%) at 3 months, 96.3% (91.9-99.9%) at 6 months, and 99.5% (99.1-99.9%) at 9 months after treatment. No significant treatment-induced adverse effects were observed.Ultrasound-guided microfoam sclerotherapy using polidocanol could be an effective and safe method for the treatment of symptomatic giant liver cysts.

Supplemental digital content is available in the text., Background Primary sclerosing cholangitis (PSC) is a progressive cholestatic liver disease, with liver transplantation being the sole life-saving treatment for end-stage PSC-related liver disease. However, recurrence of PSC after liver transplantation is a common complication, with the risk factors for recurrence being controversial. Methods We conducted a retrospective chart review of 45 patients who had undergone liver transplantation for PSC at our institute. The risk factors for PSC recurrence and graft failure after liver transplantation were analyzed. Results The graft survival rates were 55.4% at 5 years and 32.8% at 10 years after liver transplantation for PSC. PSC recurrence was diagnosed in 16 (40%) of 40 patients, at a median 30 months (range, 9-70 months) after liver transplantation. The cumulative incidence rate of PSC recurrence was 24.5% at 3 years, 39.3% at 5 years, and 45.8% at 6 years. Among the 16 patients diagnosed with PSC recurrence, the graft survival rate was 56.3% at 5 years, and 21.9% at 10 years after the recurrence. Active inflammatory bowel disease after liver transplantation was identified as an independent risk factor for PSC recurrence. Age younger than 30 years at the time of PSC diagnosis and bacteremia were factors significantly associated with graft failure after liver transplantation on multivariate analysis. Conclusions PSC frequently recurred and progressed to graft failure after liver transplantation for PSC. Maintaining an inactive status of inflammatory bowel disease might offer protection against PSC recurrence.

Aim Hepatitis B virus (HBV) reactivation after liver transplantation in HBV patients, or in HBV negative recipients of anti-hepatitis B core (HBc) positive grafts, has been prevented by prophylactic use of hepatitis B immunoglobulin (HBIG) and/or nucleoside/nucleotide analogs (NA). Vaccination against HBV is an alternative that may provide a chance to discontinue prophylaxis by producing anti-hepatitis B surface (HBs) antibodies. Methods We retrospectively reviewed 40 HBV positive recipients (HBV+ group) and 27 HBV negative recipients of anti-HBc positive grafts (HBV−/anti-HBc+ graft group), who were administrated double-dose hepatitis B vaccination. Recipients were regarded as responders when anti-HBs greater than 100 IU/L was maintained for 6 months or more without HBIG. Response rates of vaccine and long-term outcomes were analyzed. Results Eighteen of the 40 patients in the HBV+ group (45%) and 18 of the 27 patients in the HBV−/anti-HBc+ graft group (67%) responded to vaccination after a median of four and three times, respectively. Younger age was the only independent factor associated with vaccine response in the HBV−/anti-HBc+ graft group (P = 0.03), whereas no factor was found to be an independent predictor for vaccine response in the HBV+ group. Among the 18 responders in the HBV+ group, 17 remained without NA or HBIG 8.2 years after the start of vaccination. Ten of those required periodic booster vaccination. All 18 responders in the HBV−/anti-HBc+ graft group remained free from HBV prophylaxis 6.2 years after the start of vaccination. Conclusion Younger recipients have a greater chance to develop sufficient anti-HBs after double-dose HBV vaccination, leading to discontinue HBV prophylaxis.

Helicobacter pylori infection plays a crucial role in gastric carcinogenesis. H pylori exerts oncogenic effects on gastric mucosa through complex interaction between bacterial virulence factors and host inflammatory responses. On the other hand, gastric cancer develops via stepwise accumulation of genetic and epigenetic alterations in H pylori-infected gastric mucosa. Recent comprehensive analyses of gastric cancer genomes indicate a multistep process of genetic alterations as well as possible molecular mechanisms of gastric carcinogenesis. Both genetic processes of gastric cancer development and molecular oncogenic pathways related to H pylori infection are important to completely understand the pathogenesis of H pylori-related gastric cancer.

Next-generation sequencing (NGS) technologies have revolutionized cancer genomics due to their high throughput sequencing capacity. Reports of the gene mutation profiles of various cancers by many researchers, including international cancer genome research consortia, have increased over recent years. In addition to detecting somatic mutations in tumor cells, NGS technologies enable us to approach the subject of carcinogenic mechanisms from new perspectives. Deep sequencing, a method of optimizing the high throughput capacity of NGS technologies, allows for the detection of genetic aberrations in small subsets of premalignant and/or tumor cells in noncancerous chronically inflamed tissues. Genome-wide NGS data also make it possible to clarify the mutational signatures of each cancer tissue by identifying the precise pattern of nucleotide alterations in the cancer genome, providing new information regarding the mechanisms of tumorigenesis. In this review, we highlight these new methods taking advantage of NGS technologies, and discuss our current understanding of carcinogenic mechanisms elucidated from such approaches.

Hepatocellular carcinoma (HCC) is a serious therapeutic challenge, with poor prognosis. Therapeutic options for HCC are limited, particularly for the patients at advanced stage who are not eligible for curative therapies such as radio-frequency ablation (RFA), hepatectomy, or hepatic transplantation. Thus, novel approaches are urgently needed for the treatment of this prevalent malignancy. Recent advance in cancer immunotherapy such as immune checkpoint blockade has revolutionized the landscape of cancer therapy, and the efficacy of several classes of immunotherapy has been tested in clinical trials. The current issue reviewed the current status of immunotherapy for HCC as well as the unique tolerogenic character of liver immune system and the immune evasion mechanisms of HCC. Taking into the account of the immunosuppressive forces operating in the hepatic tumor microenvironment—combination therapies of different strategies might be encouraged for achieving optimal clinical outcome.

Resistance-associated variant (RAV) is one of the most significant clinical challenges in treating HCV-infected patients with direct-acting antivirals (DAAs). We investigated the viral dynamics in patients receiving DAAs using third-generation sequencing technology. Among 283 patients with genotype-1b HCV receiving daclatasvir + asunaprevir (DCV/ASV), 32 (11.3%) failed to achieve sustained virological response (SVR). Conventional ultra-deep sequencing of HCV genome was performed in 104 patients (32 non-SVR, 72 SVR), and detected representative RAVs in all non-SVR patients at baseline, including Y93H in 28 (87.5%). Long contiguous sequences spanning NS3 to NS5A regions of each viral clone in 12 sera from 6 representative non-SVR patients were determined by third-generation sequencing, and showed the concurrent presence of several synonymous mutations linked to resistance-associated substitutions in a subpopulation of pre-existing RAVs and dominant isolates at treatment failure. Phylogenetic analyses revealed close genetic distances between pre-existing RAVs and dominant RAVs at treatment failure. In addition, multiple drug-resistant mutations developed on pre-existing RAVs after DCV/ASV in all non-SVR cases. In conclusion, multi-drug resistant viral clones at treatment failure certainly originated from a subpopulation of pre-existing RAVs in HCV-infected patients. Those RAVs were selected for and became dominant with the acquisition of multiple resistance-associated substitutions under DAA treatment pressure.

Helicobacter pylori infection is the most important cause of human gastric cancer worldwide. Gastric cancer develops over a long time after H. pylori infection via stepwise accumulation of genetic alterations and positive selection of cells with growth advantages. H. pylori itself and the resultant chronic inflammation lead to the emergence of genetic alterations in gastric epithelial cells via increased susceptibility of these cells to DNA damage. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) in inflammatory and gastric epithelial cells, as well as the expression of cytidine deaminase in gastric epithelial cells, may link H. pylori-related inflammation and DNA damage. Recent comprehensive analyses of gastric cancer genomes provide clues for the possible molecular mechanisms of gastric carcinogenesis. In this chapter, we describe how genetic alterations emerge during gastric carcinogenesis related to H. pylori infection.

Scientific Reports 4: Article number: 4482; published online: 27 March 2014 updated: 16 January 2017. In this Article, an additional affiliation for Hana Huskova was omitted. The correct affiliations for this Author are listed below: Molecular Mechanisms and Biomarkers Group, International Agency for Research on Cancer, 69008 Lyon, France.