Mitsuharu Fukasawa

Deep sequencing of cancer-related genes revealed GNAS mutations to be associated with intraductal papillary mucinous neoplasms and its main pancreatic duct dilation.

Background To clarify the genetic mutations associated with intraductal papillary mucinous neoplasms (IPMN) and IPMN-related pancreatic tumours, we conducted cancer-related gene profiling analyses using pure pancreatic juice and resected pancreatic tissues. Methods Pure pancreatic juice was collected from 152 patients [nine with a normal pancreas, 22 with chronic pancreatitis (CP), 39 with pancreatic ductal adenocarcinoma (PDAC), and 82 with IPMN], and resected tissues from the pancreas were collected from 48 patients (six IPMNs and 42 PDACs). The extracted DNA was amplified by multiplexed polymerase chain reaction (PCR) targeting 46 cancer-related genes containing 739 mutational hotspots. The mutations were analysed using a semiconductor-based DNA sequencer. Results Among the 46 cancer-related genes, KRAS and GNAS mutations were most frequently detected in both PDAC and IPMN cases. In pure pancreatic juice, GNAS mutations were detected in 7.7% of PDAC cases and 41.5% of IPMN cases (p<0.001 vs. others). All PDAC cases with GNAS mutations (n = 3) were accompanied by IPMN. Multivariate analysis revealed that GNAS mutations in IPMN cases were associated with dilated main pancreatic ducts (MPD, p = 0.016), while no statistically independent associations with clinical variables were observed for KRAS mutations. In the resected pancreatic tissues, GNAS mutations were detected in 50% of PDAC cases concomitant with IPMN, 33.3% of PDAC cases derived from IPMN, and 66.7% of IPMN cases, while no GNAS mutations were detected in cases of PDAC without IPMN. Conclusions The GNAS mutation was specifically found in the cases with IPMN and it was speculated that some PDACs might be influenced by the concomitant but separately-located IPMN in their pathogenic mechanism. Furthermore, the GNAS mutation was significantly associated with MPD dilatation in IPMN cases, suggesting its role in mucus hypersecretion.

Hepatocellular carcinoma risk assessment using gadoxetic acid-enhanced hepatocyte phase magnetic resonance imaging.

To investigate whether the patients with hypovascular liver nodules determined on the arterial phase and hypointensity on the hepatocyte phase gadoxetic acid‐enhanced magnetic resonance imaging (hypovascular hypointense nodules) are at increased risk of hepatocarcinogenesis, we assessed subsequent typical hepatocellular carcinoma (HCC) development at any sites of the liver with and without such nodules.

Clinical Features and Natural History of Serous Cystic Neoplasm of the Pancreas

Aims: To clarify the clinical features and the natural history of serous cystic neoplasm (SCN) of the pancreas. Methods: We retrospectively analyzed data from 30 patients affected by SCN. SCNs were classified as (1) microcystic type, (2) micro- and macrocystic type, and (3) macrocystic type according to the modified WHO classification. Eighteen patients who underwent serial radiographic imaging were identified, and tumor growth rate in these patients was evaluated. Results: The median age was 62 years, and the female:male ratio was 2:1. Twenty-five patients (83%) were asymptomatic and 5 (17%) were symptomatic. The median tumor size was 2.6 cm. Fifteen cases (50%) had the microcystic type, 7 (23%) the micro- and macrocystic type, and 8 (27%) the macrocystic type. Age, gender, symptoms, location or tumor size did not differ significantly among the three subtypes. Eighteen patients were followed up for a median of 58 months. Morphological changes were observed in 3 patients (17%) and enlargement of tumor size in 9 patients (50%) during the follow-up. The growth rate was 0.29 cm per year and doubling time was 3.5 years; these rates did not differ among morphological subtypes or size of tumors. Conclusions: In asymptomatic patients with a clear imaging diagnosis of SCN, nonoperative management with a careful follow-up should be recommended. Surgery should be suggested in only symptomatic patients, those with giant tumors (>10 cm), rapid growing or when the presence of a potentially malignant tumor cannot be excluded.

Deep Sequencing and Phylogenetic Analysis of Variants Resistant to Interferon-Based Protease Inhibitor Therapy in Chronic Hepatitis Induced by Genotype 1b Hepatitis C Virus

ABSTRACT Because of recent advances in deep sequencing technology, detailed analysis of hepatitis C virus (HCV) quasispecies and their dynamic changes in response to direct antiviral agents (DAAs) became possible, although the role of quasispecies is not fully understood. In this study, to clarify the evolution of viral quasispecies and the origin of drug-resistant mutations induced by interferon (IFN)-based protease inhibitor therapy, the nonstructural-3 (NS3) region of genotype 1b HCV in 34 chronic hepatitis patients treated with telaprevir (TVR)/pegylated interferon (PEG-IFN)/ribavirin (RBV) was subjected to a deep sequencing study coupled with phylogenetic analysis. Twenty-six patients (76.5%) achieved a sustained viral response (SVR), while 8 patients did not (non-SVR; 23.5%). When the complexity of the quasispecies was expressed as the mutation frequency or Shannon entropy value, a significant decrease in the IFNL3 (rs8099917) TT group and a marginal decrease in the SVR group were found soon (12 h) after the introduction of treatment, whereas there was no decrease in the non-SVR group and no significant decrease in mutation frequency in the IFNL3 TG/GG group. In the analysis of viral quasispecies composition in non-SVR patients, major populations greatly changed, accompanied by the appearance of resistance, and the compositions were unlikely to return to the pretreatment composition even after the end of therapy. Clinically TVR-resistant variants were observed in 5 non-SVR patients (5/8, 62.5%), all of which were suspected to have acquired resistance by mutations through phylogenetic analysis. In conclusion, results of the study have important implications for treatment response and outcome in interferon-based protease inhibitor therapy. IMPORTANCE In the host, hepatitis C virus (HCV) consists of a variety of populations (quasispecies), and it is supposed that dynamic changes in quasispecies are closely related to pathogenesis, although this is poorly understood. In this study, recently developed deep sequencing technology was introduced, and changes in quasispecies associated with telaprevir (TVR)/pegylated interferon (PEG-IFN)/ribavirin (RBV) triple therapy and their clinical significance were investigated extensively by phylogenetic tree analysis. Through this study, the associations among treatment response, changes in viral quasispecies complexity in the early stage of treatment, changes in the quasispecies composition, and origin of TVR-resistant variant HCV were elucidated.

Stratifying the risk of lymph node metastasis in undifferentiated-type early gastric cancer

AIM To study how lymph node metastasis (LNM) risk is stratified in undifferentiated-type early gastric cancer (undiff-EGC) dependent on combinations of risk factors. METHODS Five hundred and sixty-seven cases with undiff-EGC undergoing gastrectomy with lymphadenectomy were examined retrospectively. Using clinicopathological factors of patient age, location, size, an endoscopic macroscopic tumor form, ulceration, depth, histology, lymphatic involvement (LI) and venous involvement (VI), LNM risk was examined and stratified by conventional statistical analysis and data-mining analysis. RESULTS LNM was positive in 44 of 567 cases (7.8%). Univariate analysis revealed > 2 cm, protrusion, submucosal (sm), mixed type, LI and VI as significant prognostic factors and > 2 cm and LI-positive were independent factors by multivariate analysis. In preoperatively evaluable factors excluding LVI, sm and > 2 cm were independent factors. According to the depth and size, cases were categorized into the low-risk group [m and ≤ 2 cm, 0% (LNM incidence)], the moderate-risk group (m and > 2 cm, 5.6%; and sm and ≤ 2 cm, 6.0%), and the high-risk group (sm and > 2 cm, 19.3%). On the other hand, LNM occurred in 1.4% in all LI-negative cases, greatly lower than 28.2% in all LI-positive cases, and LNM incidence was low in LI-negative cases even in the moderate- and high-risk groups. CONCLUSION LNM-related factors in undiff-EGC were depth and size preoperatively while those were LI and size postoperatively. Among these factors, LI was the most significantly correlated factor.

Performance status and neutrophil-lymphocyte ratio are important prognostic factors in elderly patients with unresectable pancreatic cancer

BACKGROUND The usefulness of various prognostic factors for pancreatic cancer (PC) has been reported, but the number of elderly patients in these studies is disproportionately fewer compared with those in everyday practice. The purpose of this study was to investigate the prognostic factors for unresectable PC in elderly patients. METHODS We retrospectively analyzed 67 elderly (age ≥75 years) patients with unresectable PC who underwent chemotherapy between January 2006 and December 2014 at our hospital. Univariate and multivariate Cox regression models were applied to investigate independent prognostic factors. RESULTS Multivariate analysis revealed that an increased neutrophil-lymphocyte ratio (NLR) [hazard ratio (HR) 1.91, P=0.03] and Eastern Cooperative Oncology Group (ECOG) performance status (PS) 2 (HR 2.74, P=0.01) were independent negative prognostic factors. CONCLUSIONS The two prognostic factors identified herein are useful in the identification of patients with a poor prognosis and subsequent administration of supportive care alone, which may help avoid the unnecessary adverse effects and complications of systemic chemotherapy.

Biliary drainage strategy of unresectable malignant hilar strictures by computed tomography volumetry.

AIM To identify criteria for predicting successful drainage of unresectable malignant hilar biliary strictures (UMHBS) because no ideal strategy currently exists. METHODS We examined 78 patients with UMHBS who underwent biliary drainage. Drainage was considered effective when the serum bilirubin level decreased by ≥ 50% from the value before stent placement within 2 wk after drainage, without additional intervention. Complications that occurred within 7 d after stent placement were considered as early complications. Before drainage, the liver volume of each section (lateral and medial sections of the left liver and anterior and posterior sections of the right liver) was measured using computed tomography (CT) volumetry. Drained liver volume was calculated based on the volume of each liver section and the type of bile duct stricture (according to the Bismuth classification). Tumor volume, which was calculated by using CT volumetry, was excluded from the volume of each section. Receiver operating characteristic (ROC) analysis was performed to identify the optimal cutoff values for drained liver volume. In addition, factors associated with the effectiveness of drainage and early complications were evaluated. RESULTS Multivariate analysis showed that drained liver volume [odds ratio (OR) = 2.92, 95%CI: 1.648-5.197; P < 0.001] and impaired liver function (with decompensated liver cirrhosis) (OR = 0.06, 95%CI: 0.009-0.426; P = 0.005) were independent factors contributing to the effectiveness of drainage. ROC analysis for effective drainage showed cutoff values of 33% of liver volume for patients with preserved liver function (with normal liver or compensated liver cirrhosis) and 50% for patients with impaired liver function (with decompensated liver cirrhosis). The sensitivity and specificity of these cutoff values were 82% and 80% for preserved liver function, and 100% and 67% for impaired liver function, respectively. Among patients who met these criteria, the rate of effective drainage among those with preserved liver function and impaired liver function was 90% and 80%, respectively. The rates of effective drainage in both groups were significantly higher than in those who did not fulfill these criteria (P < 0.001 and P = 0.02, respectively). Drainage-associated cholangitis occurred in 9 patients (12%). A smaller drained liver volume was associated with drainage-associated cholangitis (P < 0.01). CONCLUSION Liver volume drainage ≥ 33% in patients with preserved liver function and ≥ 50% in patients with impaired liver function correlates with effective biliary drainage in UMHBS.

Next-Generation Sequencing Revealed TP53 Mutations to Be Malignant Marker for Intraductal Papillary Mucinous Neoplasms That Could Be Detected Using Pancreatic Juice

Objectives The aims of this study were to identify the genetic mutations associated with malignant intraductal papillary mucinous neoplasms (IPMNs) and evaluate the possibility of detecting mutations in pure pancreatic juice by next-generation sequencing. Methods Resected tissues were collected from 50 patients with IPMN, and pure pancreatic juice samples were collected from 19 patients who had a resection. The extracted DNA was amplified by multiplex polymerase chain reaction targeting 52 cancer-related genes, including KRAS, GNAS, RNF43, and TP53; the mutations were then detected by next-generation sequencing and then analyzed for correlations with the clinicopathological characteristics. Results In the resected tissues, the most frequently detected mutations were in KRAS, GNAS, TP53, and RNF43, in 88%, 76%, 36%, and 30% of cases, respectively. Univariate and multivariate analyses revealed that only TP53 mutations were associated with malignant IPMNs (P = 0.023). In the pure pancreatic juice, TP53 mutations were detected in 5 of 10 resected samples with malignant IPMN and in 4 of 5 pancreatic juice samples with mutation in resected samples. Conclusions From 52 cancer-related gene analysis, only TP53 mutation was associated with malignant IPMNs. TP53 mutation could also be detected in pure pancreatic juice, potentially making it a useful tool to diagnose malignant IPMNs preoperatively.

Hypoechoic Lesions in Submandibular Glands Are Diagnostic Markers of Type 1 Autoimmune Pancreatitis.

Routine laboratory evaluation is often unrevealing, but possible abnormalities include the following: hypercalcemia, hypercalcuria, elevated alkaline phosphatase level, elevated angiotensin-converting enzyme levels. Regarding this case, the whole body F-FDG positron emission tomography/CTand a biopsy result stands strongly for the diagnosis of pancreatic sarcoidosis. In this case, the confirmation of AIP is based on clinical, laboratory test results, radiographic, and histological findings. The pancreatic biopsy performed by EUS-FNA had sufficient tissue for both cytological and histological diagnosis. Despite radiological advances, pancreatic masses are often difficult to diagnose until operative exploration and histological examination of biopsies. There are 25 cases of pancreatic sarcoidosiswhichwere reported having performed surgical operation as a combined diagnostic and therapeutic measure. Also, such a comprehensive surgical resection is much harmful to a patient if the final result shows a benign lesion. Compared with open biopsy, EUS-FNA biopsy has a lower risk of postoperative complications. In addition, the patient in our case did not take any medication to treat his illness, sowhether the patient would react well to therapeutic diagnosis may be another way to differentiating pancreatic sarcoidosis and other pancreatic diseases. Conclusively, we report here a case showing very uncommon combination of a pancreatic sarcoidosis and type 1 AIP. They sometimes have similar presentation and possibly share the same cause but large numbers of studies are still needed. The EUS-FNAmay present an effective and relatively secure method for differentiating pancreatic sarcoidosis and chronic pancreatitis. However, whether the sensitivity and specificity of this technique in preoperative diagnosis of pancreatic diseases are higher than those of other imaging techniques, and open biopsies still need more researches to verify.

Migration of pancreatic spontaneous dislodgement stent to the appendix

The purposes of pancreatic stenting are the treatment of pancreatic duct stricture and the prevention of postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. Here, we report a case of migration of pancreatic spontaneous dislodgement stent to the appendix, which may develop obstructive appendicitis. A 78-year-old woman was transferred to our hospital with a diagnosis of acute gallstone pancreatitis. On physical examination, she had tenderness in the upper abdomen. Laboratory data revealed leukocytosis of 13.7 ¥ 10/L and elevated C-reactive protein at 14.4 mg/dL, total bilirubin at 2.8 mg/dL, alkaline phosphatase at 626 IU/L and amylase at 1421 IU/L. ERCP was carried out to remove bile duct stones and a pancreatic spontaneous dislodgement stent was inserted to prevent post-ERCP pancreatitis. Follow-up computed tomography showed the pancreatic stent had migrated into the appendix (Fig. 1). At colonoscopy, the stent was located in the appendiceal orifice and removed with endoscopic forceps (Fig. 2).The patient did not complain of any symptoms of appendicitis throughout the clinical course. In biliary stenting, proximal or distal migrations are reported to occur. Complications of distal migration most commonly consist of enteral fistulas or overt perforation. Rare complications of appendicitis due to appendiceal obstruction by a migrated biliary stent are also reported. Pancreatic spontaneous dislodgement stent decreased the incidence of post-ERCP pancreatitis significantly in high-risk patients. To prevent post-ERCP pancreatitis, pancreatic spontaneous dislodgement stent has been frequently used in recent years. To the best of our knowledge, late complication of pancreatic spontaneous dislodgement stent has not been reported previously. It is necessary to consider the presence of this complication until the pancreatic stent is excreted from the body.