Blue laser imaging and linked color imaging improve the color difference value and visibility of colorectal polyps in underwater conditions

BACKGROUND AND AIM

Underwater endoscopic mucosal resection (UEMR) has become widespread for treating colorectal polyps. However, which observational mode is best suited for determining polyp margins underwater remains unclear. To determine the best mode, we analyzed three imaging modes: white light imaging (WLI), blue laser imaging (BLI) and linked color imaging (LCI).

METHODS

Images of consecutive colorectal polyps previously examined by these three modes before UEMR were analyzed according to the degree of underwater turbidity (transparent or cloudy). Color differences between the polyps and their surroundings were calculated using the Commission Internationale d'Eclairage Lab color space in which 3-D color parameters were expressed. Eight evaluators, who were blinded to the histology, scored the visibility from one (undetectable) to four (easily detectable) in both underwater conditions. The color differences and visibility scores were compared.

RESULTS

Seventy-three polyps were evaluated. Sixty-one polyps (44 adenomatous, 17 serrated) were observed under transparent conditions, and 12 polyps (seven adenomatous, five serrated) were observed under cloudy conditions. Under transparent conditions, color differences for the BLI (8.5) and LCI (7.9) were significantly higher than that of WLI (5.7; P < 0.001). Visibility scores for BLI (3.6) and LCI (3.4) were also higher than that of WLI (3.1; P < 0.0001). Under cloudy conditions, visibility scores for LCI (2.9) and WLI (2.7) were significantly higher than that of BLI (2.2; P < 0.0001 and P = 0.04, respectively).

CONCLUSIONS

BLI and LCI were better observational modes in transparent water; however, BLI was unsuitable for cloudy conditions.

Human Telomerase Reverse Transcriptase Gene Promoter Mutation in Serum of Patients with Hepatocellular Carcinoma

BACKGROUND

Mutations in the human telomerase reverse transcriptase (hTERT) gene promoter have been reported in hepatocellular carcinoma (HCC); however, analyses of these mutations in liquid biopsies have been technically difficult because of the high GC content of the regions of interest within this promoter. We evaluated the feasibility and prognostic value of hTERT promoter mutations identified in circulating cell-free DNA (cfDNA) from the serum of patients with HCC.

OBJECTIVE

A cohort of HCC patients (n = 36) who were curatively treated by surgical resection between June 2003 and September 2014 were enrolled in this study.

METHODS

The presence of hTERT promoter mutations in cfDNA from the patients' serum was analyzed via modified droplet digital polymerase chain reaction, and associations were sought between specific promoter mutations and patients' disease-free survival (DFS).

RESULTS

The G>A hTERT mutation at -124 bp was detected in the serum of 25 patients (69%). Although no marked differences were observed between the characteristics of the serum mutation-positive and serum mutation-negative patient groups, the DFS of patients with the mutation was significantly shorter than that of the serum mutation-negative patients (p = 0.02). Among 18 clinicopathologic and background liver factors examined, the presence of the -124 bp G>A mutation was an independent and significant predictor of patients' DFS (hazard ratio = 3.01, 95% confidence interval 1.11-10.5, p = 0.03) in multivariate analyses.

CONCLUSIONS

The -124 bp G>A hTERT promoter mutation was observed in the serum of 69% of HCC patients who underwent surgical resection and was an independent predictor of disease progression in HCC.

Observer agreement for the diagnosis of intestinal acute graft-vs.-host disease based on the presence of villous atrophy in the terminal ileum

Intestinal graft-vs.-host disease (GVHD) is a serious complication of allo-hematopoietic stem cell transplantation (allo-HSCT). Villous atrophy in the terminal ileum is considered a useful diagnostic indicator for GVHD. However, the inter- and intra-observer agreement regarding the ileocolonoscopic findings indicative of acute intestinal GVHD, i.e., villous atrophy in the terminal ileum, are currently insufficient in multiple institutions. Thus, the present study aimed to investigate the incidence of villous atrophy in the terminal ileum to diagnose acute intestinal GVHD and determine the inter- and intra-observer agreement regarding this result for experienced endoscopists from multiple institutions. Consecutive patients who underwent allo-HSCT were referred to our institution between May 2008 and September 2015. A total of 54 patients underwent total ileocolonoscopy after allo-HSCT due to suspected intestinal acute GVHD. Subsequently, three observers from different institutions evaluated the cases for the presence of villous atrophy in the terminal ileum. In this study, the pathology results were a gold standard to evaluate the predictive value of ileocolonoscopy detection. Definitive pathological and non-pathological GVHD was diagnosed in 22 and 32 cases, respectively. The results of examining whether villous atrophy could predict GVHD were as follows. For three observers (A, B and C), the sensitivity of villous atrophy in the terminal ileum was 86.4, 77.3 and 79.2%, respectively, whereas the specificity was 62.5, 62.5 and 86.7%, respectively. The positive predictive value (PPV) and negative predictive value (NPV) of villous atrophy for GVHD were as follows: The PPV of appearance was 61.3, 58.6 and 82.6%, respectively, whereas the NPV was 87.0, 80.0 and 83.9%, respectively. Kappa coefficients for the inter-observer reliability were 0.85, 0.63 and 0.63 for observers A and B, A and C, and B and C, respectively. The intra-observer kappa coefficient was 0.88 for observer A, 0.73 for observer B and 0.75 for observer C. A substantial observer agreement was achieved for the analysis of villous atrophy in the terminal ileum and the agreement for the predictive histological diagnosis was also excellent. Based on the results of the present study, identification of villous atrophy in the terminal ileum was a clinically effective diagnostic parameter, even if different endoscopists were involved in the diagnosis at multiple institutions. The present study was registered as a trial with the University Hospital Medical Information Network (UMIN; registration no. UMIN000025390).

Switching between Three Types of Mesalazine Formulation and Sulfasalazine in Patients with Active Ulcerative Colitis Who Have Already Received High-Dose Treatment with These Agents

BACKGROUND AND AIM

Oral mesalazine and sulfasalazine (SASP) are key drugs for treating ulcerative colitis (UC). The efficacy of switching from one of the several mesalazine formulations to another is largely unknown. This study assessed the efficacy of switching among three types of mesalazine formulation and SASP for UC therapy.

METHODS

UC patients receiving high-dose mesalazine/SASP who switched to other formulations due to disease activity were considered eligible. Efficacy was evaluated 2, 6, and 12 months after switching.

RESULTS

A total of 106 switches in 88 UC patients were analyzed. The efficacy at 2 months after switching was observed in 23/39 (59%) cases from any mesalazine formulation to SASP, in 18/55 (33%) cases from one mesalazine to another, and in 2/12 (17%) cases from SASP to any mesalazine formulation. Nine of 43 effective cases showed inefficacy or became intolerant post-switching. Delayed efficacy more than two months after switching was observed in four cases. Steroid-free remission was achieved in 42/106 (39%) cases-within 100 days in 35 of these cases (83%).

CONCLUSIONS

Switching from mesalazine to SASP was effective in more than half of cases. The efficacy of switching between mesalazine formulations was lower but may be worth attempting in clinical practice from a safety perspective.

Berberine improved experimental chronic colitis by regulating interferon-γ- and IL-17A-producing lamina propria CD4+ T cells through AMPK activation

The herbal medicine berberine (BBR) has been recently shown to be an AMP-activated protein kinase (AMPK) productive activator with various properties that induce anti-inflammatory responses. We investigated the effects of BBR on the mechanisms of mucosal CD4⁺T cell activation in vitro and on the inflammatory responses in T cell transfer mouse models of inflammatory bowel disease (IBD). We examined the favorable effects of BBR in vitro, using lamina propria (LP) CD4⁺ T cells in T cell transfer IBD models in which SCID mice had been injected with CD4⁺CD45RB^high T cells. BBR suppressed the frequency of IFN-γ- and Il-17A-producing LP CD4⁺ T cells. This effect was found to be regulated by AMPK activation possibly induced by oxidative phosphorylation inhibition. We then examined the effects of BBR on the same IBD models in vivo. BBR-fed mice showed AMPK activation in the LPCD4⁺ T cells and an improvement of colitis. Our study newly showed that the BBR-induced AMPK activation of mucosal CD4⁺ T cells resulted in an improvement of IBD and underscored the importance of AMPK activity in colonic inflammation.

Utility of liquid biopsy using urine in patients with pancreatic ductal adenocarcinoma

In recent years, liquid biopsy for blood and body fluid in cancer patients has attracted attention. However, there have been few reports of liquid biopsy focusing on urine of pancreatic ductal adenocarcinoma (PDAC). In 56 patients with PDAC, DNA was extracted from urine and plasma prior to treatment, and KRAS mutations were analyzed with droplet digital PCR to examine the mutation detection rate. Our study showed that KRAS mutations were found in 27 cases (48%) in urine and 27 cases (48%) in plasma. The detection rate of urine KRAS mutations varied by renal functions. The rates were 70% (14/20) and 36% (13/36) in the creatinine clearance rate (CCr) < 70 mL/min group and in the CCr ≥ 70 mL/min group, respectively (P = .024). Whereas, no influence of the CCr was observed in the detection rates of plasma KRAS mutations. The rates were 50% (10/20) and 47% (17/36) in cases with the CCr < 70 mL/min group and the CCr ≥ 70 mL/min group, respectively. Although the sample size was small, this study clearly indicated a new possibility of less invasive urine liquid biopsy in PDAC patients.

Comparison of Two Electrosurgical Modes for Endoscopic Submucosal Dissection of Superficial Colorectal Neoplasms: A Prospective Randomized Study

Endoscopic submucosal dissection (ESD) is reportedly one of the standard treatment strategies for large superficial colorectal neoplasms in Japan because of its high en bloc resection rate. A few technical issues regarding ESD should be considered, one of which is the selection of the Endo-cut I mode versus the Swift-coagulation mode as the electrosurgical unit mode setting during submucosal dissection. We seek to determine which of these two modes is more suitable for submucosal dissections of colorectal tumors with regard to procedure time and safety.

The Progression of Esophageal Mucosa-associated Lymphoid Tissue Lymphoma after Helicobacter pylori Eradication Therapy: A Case Report and Discussion of Therapeutic Options

A 50-year-old woman with epigastric discomfort was referred to our hospital. Esophagogastroduodenoscopy showed flat, elevated, submucosal tumor-like lesions in the esophagus. Extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) of the esophagus was diagnosed based on the examination of an endoscopic biopsy specimen. Computed tomography showed the enlargement of a lymph node in the gastric cardia. The present case showed disease progression despite Helicobacter pylori eradication therapy and achieved partial remission after rituximab monotherapy. The patient remained in partial remission for 20 months. This case suggests that esophageal MALT lymphoma with lymph node involvement does not respond to H. pylori eradication therapy and that it requires systemic treatment.

Dexmedetomidine for conscious sedation with colorectal endoscopic submucosal dissection: a prospective double-blind randomized controlled study

Objective

Conscious sedation for colorectal endoscopic submucosal dissection (ESD) has not been standardized, and there are no studies of sedation for colorectal ESD.

Methods

We conducted a prospective double-blind randomized controlled trial to clarify the usefulness of DEX during colorectal ESD. In total 80 patients with colorectal ESD from April 2016 to May 2017 were assigned to the placebo group or the DEX group (40 cases each). The primary outcome was patient satisfaction (visual analogue scale: VAS). Secondary outcomes were evaluated for 13 factors, including patient pain level (VAS), endoscopist satisfaction (VAS), objective patient pain level viewed from the endoscopist’s perspective (VAS), rate of patient response, rate of side effects, etc., from the patient’s and endoscopist’s perspectives.

Results

Patient satisfaction was 8.4 and 9.1 (P = 0.018) in the placebo group and the DEX group, respectively. Secondary outcomes of patient pain level, endoscopist satisfaction, objective patient pain level from the endoscopist’s perspective for the placebo and DEX groups were 1.2 and 0.4 (P = 0.045), 8.2 and 9.3 (P < 0.001), and 1.2 and 0.5 (P = 0.002), respectively. All of these were significantly positive results (more comfortable and less pain) in the DEX group. The rate of a patient response was 100% in all cases. The side effects (hypoxia/bradycardia/hypotension) were 0%/0%/0% and 7.5%/7.5%/5% (P = 0.030). However, these rates were less than the reported side effect occurrence rate, and no additional medication was needed.

Conclusion

DEX enables conscious sedation, and is useful not only for patient and endoscopist satisfaction but also for pain relief. DEX is an effective sedation method for colorectal ESD.

Liquid biopsy of bile for the molecular diagnosis of gallbladder cancer

INTRODUCTION

Tissue sampling of gallbladder cancer (GBCa) is challenging because of the anatomy of the gallbladder. The aim of this study is to investigate the possibility of diagnosing GBCa patients by performing a liquid biopsy of bile in addition to current diagnostic methods.

METHODS

Thirty patients with GBCa were enrolled in this study. Cytological examination was performed in all patients. Using next generation sequencing (NGS), DNA isolated from the bile and tumor tissue was analyzed for mutations in 49 oncogenes. We also compared these mutations with cytology results.

RESULTS

57.1% of DNA samples from tumor tissue were positive for a mutation. In these patients, 87.5% of the bile circulating tumor DNA (ctDNA) samples had the same mutation. The concordance rate between bile ctDNA and tissue DNA samples was 85.7%, and the mutation frequencies detected in ctDNA were approximately half of what was detected in tumor tissue DNA. On the other hand, the sensitivity of the cytological and bile ctDNA analyses was 45.8% and 58.3%, respectively. The concordance rate between cytology and bile ctDNA analyses was 87.5%.

CONCLUSIONS

Mutated tumor DNA could be detected in bile by NGS. Liquid biopsy of bile might help us to diagnose GBCa because of higher sensitivity and positive predict value compared to cytology with ERCP.

[Gastric type adenoma with submucosal invasive carcinoma:a case study]

A 75-year-old woman visited our hospital for the examination of esophagogastroduodenoscopy (EGD) without any major complaint. The patient's medical history included hypertension, but no carcinoma. EGD revealed a 30-mm elevated lesion located in the anterior wall of the upper region of the stomach. The lesion, which was a 0-IIa+I type lesion with fading-like and light flare-like domains, was surgically removed using endoscopic submucosal dissection (ESD) and then the patient was diagnosed with gastric type adenoma with submucosal invasive carcinoma. To the best of our knowledge, this is the first report of a gastric type adenoma with submucosal invasive carcinoma and may therefore provide significant insights into the malignant potential of gastric type adenoma lesions.

Fibroblast growth factor-2-mediated FGFR/Erk signaling supports maintenance of cancer stem-like cells in esophageal squamous cell carcinoma

In esophageal squamous cell carcinoma (ESCC), a subset of cells defined by high expression of CD44 and low expression of CD24 has been reported to possess characteristics of cancer stem-like cells (CSCs). Novel therapies directly targeting CSCs have the potential to improve prognosis of ESCC patients. Although fibroblast growth factor-2 (FGF-2) expression correlates with recurrence and poor survival in ESCC patients, the role of FGF-2 in regulation of ESCC CSCs has yet to be elucidated. We report that FGF-2 is significantly upregulated in CSCs and significantly increases CSC content in ESCC cell lines by inducing epithelial-mesenchymal transition (EMT). Conversely, the FGFR inhibitor, AZD4547, sharply diminishes CSCs via induction of mesenchymal-epithelial transition. Further experiments revealed that MAPK/Erk kinase (Mek)/extracellular signal-regulated kinases (Erk) pathway is crucial for FGF-2-mediated CSC regulation. Pharmacological inhibition of FGF receptor (FGFR)-mediated signaling via AZD4547 did not affect CSCs in Ras mutated cells, implying that Mek/Erk pathway, downstream of FGFR signaling, might be an important regulator of CSCs. Indeed, the Mek inhibitor, trametinib, efficiently suppressed ESCC CSCs even in the context of Ras mutation. Consistent with these findings in vitro, xenotransplantation studies demonstrated that inhibition of FGF-2-mediated FGFR/Erk signaling significantly delayed tumor growth. Taken together, these findings indicate that FGF-2 is an essential factor regulating CSCs via Mek/Erk signaling in ESCC. Additionally, inhibition of FGFR and/or Mek signaling represents a potential novel therapeutic option for targeting CSCs in ESCC.

Utility of serum DNA as a marker for KRAS mutations in pancreatic cancer tissue

BACKGROUND/OBJECTIVES

The detection of cancer-specific DNA in peripheral blood, known as a liquid biopsy, has been reported recently. Most such studies have used plasma as a sample; however, whether or not serum can be used as effectively is unclear. We attempted to clarify suitable samples for detecting KRAS mutations in circulating DNA in the blood of pancreatic cancer patients using droplet digital polymerase chain reaction (PCR).

METHODS

DNA was extracted from the tissue, plasma, and serum of 40 pancreatic cancer patients. The presence of KRAS mutations G12D, G12V, and G12R was analyzed by droplet digital PCR.

RESULTS

The amount of DNA isolated from the serum was much higher than that from plasma (1.0- to 42.0-fold). At least 1 KRAS mutation was observed in 93% of cancer tissues, whereas we detected the mutations in only 48% of the serum and plasma DNA samples. The G12D mutation was the most prevalent of the three mutations, followed by the G12V mutation. The presence of the G12D KRAS mutation in the plasma, serum, or tissue did not correlate to the overall survival; however, the prognosis of the patients with a KRAS mutation at G12V in the plasma or serum was significantly poorer than that of the patients without the mutation (P < 0.01).

CONCLUSIONS

Serum and plasma were found to be good materials for detecting cancer-specific DNA in the peripheral blood and the presence of KRAS mutations in blood-derived DNA may be used as a prognostic biomarker for patients with pancreatic cancer.

Potential of alpha-fetoprotein as a prognostic marker after curative radiofrequency ablation of hepatocellular carcinoma

AIM

Recurrence of hepatocellular carcinoma (HCC) is observed frequently, even after curative treatments. The aim of this study is to elucidate the risk factors for recurrence of HCC after radiofrequency ablation (RFA), focusing on the carcinogenic potential of the liver assessed by α-fetoprotein (AFP).

METHODS

We enrolled 357 consecutive patients who underwent complete ablation by RFA for primary HCC (≤3 cm, ≤3 tumors) and analyzed the correlation between 17 critical parameters, including AFP and HCC recurrence.

RESULTS

Recurrence was observed in 236 patients during a mean observation period of 54.3 months. Multivariate analysis revealed that multiple tumors (risk ratio [RR] = 1.70, 95% confidence interval [CI] = 1.27-2.26, P < 0.001), high AFP (>10 ng/mL, RR = 1.45, 95% CI = 1.09-1.94, P < 0.001) and high des-γ-carboxyprothrombin (>40 mAU/mL, RR = 1.52, 95% CI = 1.13-2.02, P < 0.005) were significantly correlated with recurrence. AFP was selected as a significant factor even when the cut-off level was set lower (≤5 ng/mL). The risk of recurrence increased linearly according to the increase of the lowest AFP level after RFA and the adjusted ratios relative to AFP less than 5 ng/mL were 1.56, 2.14, 2.57 and 3.13 in AFP 5-10 ng/mL, 10-20 ng/mL, 20-50 ng/mL and over 50 ng/mL, respectively. In addition, the recurrence rate was predicted by the AFP level after RFA, regardless of the level before the treatment.

CONCLUSION

AFP less than 5 ng/mL after curative RFA was an important predictor of a better prognosis and was considered to indicate the low carcinogenic potential of the non-cancerous liver.

Alteration of serum N-glycan profile in patients with autoimmune pancreatitis

OBJECTIVES

The aims of this study were to determine the change in whole-serum N-glycan profile in autoimmune pancreatitis (AIP) patients and to investigate its clinical utility.

METHODS

We collected serum from 21 AIP patients before any treatment, and from 60 healthy volunteers (HLTs). Serum glycan profile was measured by comprehensive and quantitative high-throughput glycome analysis.

RESULTS

Of the 53 glycans detected, 14 were differentially expressed in AIP patients. Pathway analysis demonstrated that agalactosyl and monogalactosyl bi-antennary glycans were elevated in AIP patients. Among the 14 glycans, #3410, #3510, and #4510 showed high area under receiver operating characteristic (AUROC) values (0.955, 0.964, and 0.968 respectively) for the diagnosis of AIP. These three glycans were mainly bound to immunoglobulin G; however, their serum levels were significantly higher, even in AIP patients who showed lower serum IgG4 levels, than in HLTs.

CONCLUSIONS

We demonstrated, for the first time, whole-serum glycan profiles of AIP patients and showed that the levels of glycans #3410, #3510, and #4510 were increased in AIP patients. These glycans might be valuable biomarkers of AIP.

Alteration of N-glycan profiles in patients with chronic hepatitis and hepatocellular carcinoma

AIM

Most of the modification of N-glycosylation reported in cancers including hepatocellular carcinoma (HCC) were based on the examinations of a small number of patients or particular proteins. The aim of this study is to reveal changes in whole serum N-glycan profiles systematically during the process of hepatocarcinogenesis and to elucidate their clinical application.

METHODS

We analyzed sera from 105 patients with chronic hepatitis/liver cirrhosis (CH/LC) and age-/sex-matched healthy volunteers (HLT), as well as from 114 patients with HCC. Serum N-glycan profiles were measured comprehensively by a new, quantitative, high-throughput method and compared with clinical parameters.

RESULTS

The total amount of N-glycan expression was significantly higher in patients with CH/LC than in HLT; however, no differences were observed between CH/LC and HCC patients. In HCC patients, multi-antennary glycans with fucose residues, particularly m/z 3195, were increased compared with CH/LC patients. The expression of m/z 3195 was high, especially in patients with a high number of intrahepatic lesions (>3), large tumor size (>3 cm), macroscopic vascular invasion or metastasis. The ratio of pairs of glycans on the same path of the biosynthesis pathway (m/z 3195/1914) showed a higher area under the receiver-operator curve of 0.810 than any other single glycan to distinguish HCC from CH/LC.

CONCLUSION

We demonstrate the full spectrum of the alterations of serum N-glycans comprehensively in patients with liver disease, and elucidate the possible use of glycans as novel biomarkers of liver disease progression.

Clair D, Klein-Szanto A, Avadhani N, Diehl A, Rustgi A, Nakagawa H. Abstract 1254: Mitochondrial SOD2 regulates EMT and cancer stem cell-like cell populations

Epithelial-mesenchymal transition (EMT) is involved in cancer cell invasion, metastasis and treatment failure. EMT may promote conversion of a subset of cancer cells defined by low expression of CD44 (CD44L) to those with high expression of CD44 (CD44H), the latter associated with increased malignant properties of cancer cells. Triggered by a variety of stimuli such as transforming growth factor (TGF)-β, hypoxia and chemoradiation, EMT may be activated in cancer cells via stress-induced reactive oxygen species (ROS) in the tumor microenvironment. Excessive ROS may cause cell death or senescence; however, cells undergoing EMT may require a physiological level of ROS. It remains elusive as to how cellular antioxidant capabilities may influence EMT. Mitochondrial superoxide dismutase 2 (SOD2) is frequently overexpressed in oral and esophageal cancers. Here, we investigated mechanisms of SOD2 transcriptional regulation in EMT as well as the functional role of this antioxidant in EMT. Using well-characterized genetically engineered oral and esophageal human epithelial cell lines coupled with RNA interference (RNAi) and flow cytometric approaches, we find that TGF-β stimulates EMT, resulting in conversion of CD44L to CD44H cells, the latter of which display SOD2 upregulation. SOD2 induction in transformed cells was concurrent with suppression of TGF-β-mediated induction of both ROS and senescence. SOD2 gene expression appeared to be transcriptionally regulated by NF-κB and ZEB2, but not ZEB1. Moreover, SOD2-mediated antioxidant activity may restrict conversion of CD44L cells to CD44H cells at the early stages of EMT. In aggregate, this study provides novel mechanistic insights into the dynamic expression of SOD2 during EMT and delineates a functional role for SOD2 in EMT, influencing distinct CD44L and CD44H subsets of cancer cells that have been implicated in oral and esophageal tumor biology.

Note: This abstract was not presented at the meeting.

Citation Format: Kelly A. Whelan, Hideaki Kinugasa, Koji Tanaka, Satish Srinivasan, Manti Guha, Daret St. Clair, Andres Klein-Szanto, Narayan Avadhani, Alan Diehl, Anil Rustgi, Hiroshi Nakagawa. Mitochondrial SOD2 regulates EMT and cancer stem cell-like cell populations. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1254. doi:10.1158/1538-7445.AM2015-1254

Detection of K-ras gene mutation by liquid biopsy in patients with pancreatic cancer

BACKGROUND

Cell-free circulating tumor DNA (ctDNA) in serum has been considered to be a useful candidate for noninvasive cancer diagnosis. The current study was designed to estimate the clinical usefulness of genetic analysis for ctDNA by digital polymerase chain reaction in patients with pancreatic cancer.

METHODS

The authors compared K-ras mutations detected in endoscopic ultrasound-guided fine-needle aspiration biopsy tissue DNA and in ctDNA from 75 patients with pancreatic cancer. K-ras mutations in the serum of 66 independent, consecutive patients with pancreatic cancer were also analyzed and the authors compared the results with survival rates.

RESULTS

The frequencies of the mutations in tissue samples at G12V, G12D, and G12R in codon 12 were 28 of 75 samples (37.3%), 22 of 75 samples (29.3%), and 6 of 75 samples (8.0%), respectively. Conversely, the rates of the mutations in ctDNA were 26 of 75 samples (34.6%), 29 of 75 samples (38.6%), and 4 of 75 samples (5.3%), respectively. Overall, the K-ras mutation rates in tissue and ctDNA were 74.7% and 62.6%, respectively, and the concordance rate between them was 58 of 75 samples (77.3%). Survival did not appear to differ by the presence of K-ras mutations in tissue DNA, but the survival of patients with K-ras mutations in ctDNA was significantly shorter than that of patients without mutations in both a development set (P = .006) and an independent validation set (P = .002). The difference was especially evident in cases with a G12V mutation.

CONCLUSIONS

Analysis of ctDNA is a new useful procedure for detecting mutations in patients with pancreatic cancer. This noninvasive method may have great potential as a new strategy for the diagnosis of pancreatic cancer as well as for predicting survival.

Low frequency of drug-resistant virus did not affect the therapeutic efficacy in daclatasvir plus asunaprevir therapy in patients with chronic HCV genotype-1 infection

BACKGROUND

The efficacy of a direct-acting antiviral agent (DAA) is compromised by the development of drug resistance. The associations between resistance-associated virus (RAV) and therapeutic outcomes have not been well-understood.

METHODS

A total of 30 patients with HCV genotype-1b were enrolled and treated for 24 weeks with asunaprevir (ASV) and daclatasvir (DCV). Viral sequences in non-structural (NS) regions 3 and 5A in serum and liver tissue before treatment were examined with direct sequencing, next-generation sequencing (NGS) and the PCR-invader method to evaluate the importance of drug-resistance in the prediction of the outcomes of ASV plus DCV therapy.

RESULTS

Of 30 patients (22 treatment-naive patients, 2 interferon-intolerant patients and 6 non-responders), 25 patients (83.3%) achieved sustained virological response (SVR) 24 weeks after the treatment. Viral breakthrough occurred in three treatment-naive patients and one non-responder. One treatment-naive patient experienced viral relapse. Among 25 patients without RAV, 24 obtained SVR, whereas 5 patients had RAV with a 1.3 to 88% frequency, resulting in various therapeutic outcomes. As for HCV compartments, similar RAVs were detected in serum and liver tissue for a patient obtaining SVR despite HCV NS5A Y93H and another developed viral breakthrough although no RAV was detected. Direct sequencing could not detect RAVs in low frequency (1.3 to 12%) for three of four patients.

CONCLUSIONS

Low frequency of RAVs might not affect the outcomes of ASV plus DCV therapy. Deep sequencing and PCR-invader methods can detect clinically significant RAVs for ASV plus DCV therapy.

Serum N-glycan profiles in patients with intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND/OBJECTIVES

Diagnosing the invasiveness of intraductal papillary mucinous neoplasms (IPMNs) is difficult, especially by blood test. Alterations in serum glycan profiles have been reported for several cancers, but changes in serum glycan profiles have not been investigated in patients with IPMNs. The objectives of this study were to determine the serum N-glycan profile and to investigate its clinical utility in patients with IPMNs.

METHODS

We measured serum N-glycan profiles in 79 patients with IPMNs, including 13 invasive IPMNs, by performing comprehensive glycome analysis and assessed the relationship between N-glycan changes and clinical parameters.

RESULTS

Seventy glycans were identified and their expression profiles were significantly different depending on the cyst size, the presence of an enhancing solid component, and the histological grade of the IPMN. Nine glycans were highly expressed in patients with invasive IPMNs. The glycan m/z 3195, which is a fucosylated tri-antennary glycan, had the highest diagnostic value for distinguishing invasive IPMNs from non-invasive IPMNs (area under the receiver operating characteristic curve = 0.803). Multivariate analyses revealed high levels of m/z 3195 [odds ratio (OR), 20.5; 95% confidence interval (CI) 2.60-486.4] and the presence of enhancing solid components (OR, 35.8; 95% CI, 5.39-409.6) were significant risk factors for invasive IPMNs.

CONCLUSIONS

We performed a comprehensive evaluation of the changes in serum N-glycan profiles in patients with IPMNs for the first time. We determined that increased expression of fucosylated complex-type glycans, especially m/z 3195, is a potential marker for invasive IPMNs.