Prognostic performance of microscopic size measurements in small invasive carcinomas arising in intraductal papillary mucinous neoplasms of the pancreas.

AIMS: Small invasive carcinomas arising in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can present as multiple, small foci. In such cases, there is no clear optimal measurement method for determining the invasive size for tumour staging and prognostication. METHODS: In all, 117 small invasive IPMNs (size of largest invasive component ≤2 cm) from seven institutions (2000-2016) were reviewed, and all individual foci of invasive carcinoma were measured. T stages (AJCC 8th edition) based on the largest single focus size (LS), average size of all foci (AS), and total sum of all foci (TS) were examined in association with clinicopathologic parameters and patient outcomes. RESULTS: The cohort comprised IPMNs with invasive tubular-type (n = 82, 70%) and colloid-type (n = 35, 30%) carcinomas. The mean LS, AS, and TS were 0.86, 0.71, and 1.32 cm, respectively. Based on the LS, AS, and TS, respectively, 48, 65, and 39 cases were classified as pT1a; 22, 18, and 11 cases as pT1b; and 47, 34, and 50 cases as pT1c. Higher pT stages based on all measurements were significantly associated with small vessel, large vessel, and perineural invasion (P < 0.05). LS-, AS-, and TS-based pT stages were not significantly associated with recurrence-free survival (RFS) or overall survival (OS) by univariate or multivariate analyses. However, among tubular-type carcinomas, higher LS-, AS-, and TS-based pT stages trended with lower RFS (based on 1-, 3-, and 5-year survival rates). All microscopic measurement methods were most predictive of RFS and OS using a 1.5-cm cutoff, with LS significantly associated with both RFS and OS by univariate and multivariate analysis. CONCLUSIONS: For invasive tubular-type carcinomas arising in IPMN, microscopic size-based AJCC pT stages were not significant predictors of patient outcomes. However, for LS, a size threshold of 1.5 cm was optimal for stratifying both RFS and OS. The AJCC 8th ed. may not be applicable for stratifying small invasive IPMNs with colloid-type histology that generally portend a more favourable prognosis.

Prognostic Impact of Preoperative Osteosarcopenia for Patients with Pancreatic Ductal Adenocarcinoma After Curative Resection.

BACKGROUNDS: The clinical significance of preoperative osteosarcopenia in pancreatic ductal adenocarcinoma (PDAC) has not been fully studied. The purpose of this study was to evaluate the role of preoperative osteosarcopenia in predicting the survival of patients with PDAC. METHODS: We retrospectively analyzed 265 patients who underwent curative surgical resection for PDAC between 2012 and 2018 in two Japanese institutes. The skeletal muscle index at the L3 vertebrae and the bone mineral density at the Th11 vertebra were calculated for the evaluation of osteosarcopenia before surgery. The relationship between perioperative osteosarcopenia and clinicopathological factors and prognosis was analyzed. RESULTS: The median overall survival (OS) and disease-free survival (DFS) of patients with osteosarcopenia were significantly shorter than those of patients without osteosarcopenia (OS: 23 and 48 months, respectively, P < 0.001; DFS: 13.4 and 21.2 months, respectively, P = 0.004). On multivariate analysis, osteosarcopenia was found to be an independent factor associated with OS (hazard ratio [HR] 1.98; 95% confidence interval [CI] 1.40-2.80; P < 0.001) and DFS (HR 1.53; 95% CI 1.11-2.10; P = 0.009). CONCLUSIONS: Preoperative osteosarcopenia may be a useful prognostic factor in patients with PDAC who undergo surgical resection. Further studies are needed to assess whether perioperative, nutritional interventions and rehabilitation contribute to improving the prognosis of these patients.

A left-sided approach for wide mobilization of the pancreas with complete dissection of the Treitz ligament (with video).

BACKGROUND: In recent years, the number of minimally invasive pancreatoduodenectomy (MIPD) has been increasing; however, the procedure has not been widely accepted due to its complexity and difficulty. We have developed a technique to mobilize the pancreas head using a left-sided approach with a focus on the complete dissection of the Treitz ligament. METHODS: This technique focuses on the secure mobilization of the pancreas head using a left-sided approach. First, the transverse mesocolon is flipped upward and the anterior side of the mesojejunum is excised to expose the first jejunal artery (1st JA) from the distal side to its origin. During the procedure, the left sides of the SMA and Treitz ligament are exposed. The Treitz ligament is retracted to the left side and dissected anteriorly. Thereafter, the jejunum is flipped to the right side and the retroperitoneum around the origin of the jejunum and duodenum is dissected to identify the inferior vena cava (IVC). The rest of the Treitz ligament is dissected posteriorly and complete resection of the Treitz ligament releases the limitation of duodenal immobility. Thereafter, dissection proceeds along the anterior wall of the IVC, and mobilization of the pancreas head is completed from the left side. RESULTS: A total of 75 consecutive patients underwent MIPD from April 2016 to July 2022. The median operation times of laparoscopic and robotic procedures were 528 min (356-757 min) and 739 min (492-998 min), respectively. The volume of blood loss during laparoscopic and robotic procedures was 415 g (60-4360 g) and 211 g (17-1950 g), respectively. There was no mortality in any of the cases. CONCLUSION: Mobilization of the pancreas head and left-sided approach using a caudal view will be a safe and useful technique for MIPD.

Minimally invasive distal pancreatectomy for pancreatic cancer: cranial-to-caudal approach with identification of Gerota's fascia (with video).

BACKGROUND: Although radical antegrade modular pancreatosplenectomy for pancreatic ductal adenocarcinoma (PDAC) has become the gold standard procedure in open distal pancreatectomy, there has been no gold standardized procedure for PDAC in minimally invasive distal pancreatectomy (MIDP). In this study, we analyzed our novel cranial-to-caudal approach (CC approach) for patients undergoing MIDP and provide a video clip illustrating the details of the CC approach. METHODS: Ninety-four patients who underwent MIDP with splenectomy between 2016 and 2021 were included in this study. The CC approach was performed in 23 (24.5%) of the 94 patients. The concept of the CC approach is easy identification of Gerota's fascia from the cranial side of the pancreas and secure tumor removal (R0 resection) wrapped by Gerota's fascia. The short- and long-term outcomes were compared between the CC and non-CC approaches. RESULTS: The median operation time and blood loss were similar between the two groups. The ratios of grade ≥ B postoperative pancreatic fistula and Clavien-Dindo grade ≥ III complications were also comparable. All patients in the CC approach group achieved R0 resection, and the R0 ratio was similar in the two groups (p = 0.345). The 2-year survival rate in CC and non-CC approach groups was 87.5% and 83.6%, respectively (p = 0.903). CONCLUSIONS: The details of the CC approach for MIDP were demonstrated based on an anatomical point of view. This approach has the potential to become a standardized approach for left-sided PDAC.

Clinical Outcomes of Inside Stents and Conventional Plastic Stents as Bridge-to-Surgery Options for Malignant Hilar Biliary Obstruction.

BACKGROUND: The appropriate method of preoperative endoscopic biliary drainage (EBD) for cholangiocarcinoma with hilar biliary obstruction remains controversial. The inside-stent technique is a method of placing plastic stents entirely inside the bile duct. Several studies of patients with unresectable stage have reported longer stent patency compared with conventional endoscopic biliary stenting (EBS). Inside-stent techniques have been introduced as a bridge-to-surgery option and as an alternative to conventional EBS. AIMS: We aimed to evaluate the clinical outcomes of inside stent use and conventional EBS. METHODS: During this retrospective multicenter study, we reviewed consecutive patients with cholangiocarcinoma who underwent radical surgery after conventional EBS or inside-stent insertion. Adverse event (AE) rates after EBD and post-surgical AEs were compared. A multivariable analysis was performed to identify factors affecting cholangitis after EBD. RESULTS: Conventional EBS and inside-stent procedures were performed for 56 and 73 patients, respectively. Patient backgrounds were similar between groups, except for percutaneous transhepatic portal vein embolization. The waiting time before surgery was similar between groups (28.5 days vs. 30 days). There were no significant differences in the cholangitis rate (21.4% vs. 26.0%; P = 0.68) and all AEs (25.0% vs. 30.1%; P = 0.56) between groups. The post-surgical AE rate was similar between the groups. The multivariable analysis found that preprocedural cholangitis was a risk factor for cholangitis after EBD (odds ratio: 5.67; 95% confidence interval: 1.61-19.9). CONCLUSIONS: The outcomes of inside-stent techniques and conventional EBS for the management of preoperative EBD are comparable for patients with cholangiocarcinoma.

Risks and benefits of pancreaticoduodenectomy in patients aged 80 years and over.

PURPOSE: The frequency of pancreaticoduodenectomy is increasing in oldest old patients owing to population aging. We aimed to clarify the clinical significance of pancreaticoduodenectomy in patients aged ≥ 80 years with multiple underlying diseases. METHODS: A total of 649 consecutive patients who underwent pancreaticoduodenectomy from April 2010 to March 2021 in our institute were divided into two groups according to their age: ≥ 80 years (51) and ≤ 79 years (598). We compared mortality and morbidity between the groups. The age-related prognosis was analyzed in 302 patients who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma treatment. RESULTS: There were no significant differences in morbidity (Clavien-Dindo classification grade III or higher; P = 0.1300), mortality (P = 0.0786), or postoperative hospital stay (P = 0.5763) between the groups. Patients aged ≥ 80 years, who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma, had shorter overall survival than those aged ≤ 79 years (median survival time, 16.7 months vs. 32.7 months; P = 0.0206). However, the overall survival of patients aged ≥ 80 years who received perioperative chemotherapy was comparable to that of patients aged ≤ 79 years (P = 0.9795). In the multivariate analysis, the absence of perioperative chemotherapy was identified as an independent prognostic factor, while age ≥ 80 years was not. Perioperative chemotherapy was the sole independent prognostic factor in patients aged ≥ 80 years who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma. CONCLUSIONS: Pancreaticoduodenectomy is safe for patients aged ≥ 80 years. The survival benefits of pancreaticoduodenectomy for patients with pancreatic ductal adenocarcinoma aged ≥ 80 years might be limited to those who can receive perioperative chemotherapy.

Endoscopic nasobiliary drainage versus endoscopic biliary stenting for preoperative biliary drainage in patients with malignant hilar biliary obstruction: Propensity score-matched multicenter comparative study.

OBJECTIVES: For preoperative biliary drainage (PBD) of malignant hilar biliary obstruction (MHBO), current guidelines recommend endoscopic nasobiliary drainage (ENBD) due to the higher risk of cholangitis after endoscopic biliary stenting (EBS) during the waiting period before surgery. However, few studies have supported this finding. Therefore, we aimed to compare the outcomes of preoperative ENBD and EBS in patients with MHBO. METHODS: Patients with MHBO who underwent laparotomy for radical surgery after ENBD or EBS were included from retrospectively collected data from 13 centers (January 2014 to December 2018). We performed a 1:1 propensity score matching between the ENBD and EBS groups. These patients were compared for the following: cholangitis and all adverse events (AEs) after endoscopic biliary drainage (EBD) until surgery, time to cholangitis development after EBD, postsurgical AEs, and in-hospital death after surgery. RESULTS: Of the 414 patients identified, 355 were analyzed in this study (226 for ENBD and 129 for EBS). The matched cohort included 63 patients from each group. The proportion of cholangitis after EBD was similar between the two groups (20.6% vs. 25.4%, P = 0.67), and no significant difference was observed in the time to cholangitis development. The proportions of surgical site infections, bile leaks, and in-hospital mortality rates were similar between the groups. CONCLUSION: For PBD of MHBO, the proportion of AEs, including cholangitis, after EBD until surgery was similar when either ENBD or EBS was used.

Extensive (subtotal) distal pancreatectomy for pancreatic ductal adenocarcinoma: a propensity score matched cohort study of short- and long-term outcomes compared with those of conventional distal pancreatectomy.

PURPOSE: Extensive distal pancreatectomy (ExDP) can transect the pancreatic parenchyma more from the right side than conventional distal pancreatectomy (CDP) can. This study aimed to evaluate the short- and long-term outcomes of ExDP for pancreatic ductal adenocarcinoma (PDAC) of the pancreatic body, located adjacent to the portal vein (PV). METHODS: Medical records of 98 patients who underwent ExDP (n = 15) or CDP (n = 83) for PDAC were retrospectively reviewed. Short- and long-term outcomes of the two groups were compared. Propensity score matched analysis was additionally performed to minimize the impact of treatment allocation bias. RESULTS: In the total cohort, the CDP group had a significantly higher proportion of pancreatic tail lesions (P < 0.01), higher proportion of males, and larger tumor size. Of the 15 patients who underwent ExDP, 11 could be matched. These differences of patients' characteristics were not observed after matching. Before and after matching, the duration of surgery, blood loss, rate of morbidity including pancreatic fistula, and postoperative course were comparable between the groups. The rate of recurrence and recurrence pattern were also not significantly different between the groups. ExDP for PDAC of the pancreatic body near the PV did not increase local or lymph node recurrence. The disease-free and overall survival did not differ between the groups. CONCLUSIONS: Surgical and oncological outcomes after ExDP for PDAC were acceptable and comparable to those after CDP. ExDP is a feasible procedure, and could be an option for the treatment of PDAC of the pancreatic body near PV.

Evaluation of relationship between splenic artery and pancreatic parenchyma using three-dimensional computed tomography for laparoscopic distal pancreatectomy.

AIM: Isolating the root of the splenic artery (SPA) is a challenging procedure in laparoscopic distal pancreatectomy (LDP). We investigated the usefulness of evaluation of the relationship between the SPA and pancreatic parenchyma using three-dimensional computed tomography (3D-CT). METHODS: In total, 104 patients were evaluated. The relationship between the SPA and pancreatic parenchyma was classified into two types: buried and non-buried. Video clips of 50 patients who underwent LDP requiring isolation of the SPA root were reviewed to determine whether the classification is related to difficulty of LDP. RESULTS: Of the 50 assessed patients who underwent LDP, the relationship between the SPA and pancreatic parenchyma was the buried type in 30 (60.0%) and non-buried type in 20 (40.0%). The buried type was associated with a significantly longer median operative time than the non-buried type (285.0 vs. 235.5 min, respectively; P < 0.01). The median time required to isolate the SPA in the buried type (25.8 min; range, 4.0-101 min) was significantly longer than that in the non-buried type (7.0 min; range, 1.0-27.0 min) (P < 0.001). CONCLUSION: Preoperative 3D-CT around the pancreas is practical for predicting the difficulty of SPA isolation and determining the safety of the procedure.

A pipeline for rapidly generating genetically engineered mouse models of pancreatic cancer using in vivo CRISPR-Cas9-mediated somatic recombination.

Genetically engineered mouse models (GEMMs) that recapitulate the major genetic drivers in pancreatic ductal adenocarcinoma (PDAC) have provided unprecedented insights into the pathogenesis of this lethal neoplasm. Nonetheless, generating an autochthonous model is an expensive, time consuming and labor intensive process, particularly when tissue specific expression or deletion of compound alleles are involved. In addition, many of the current PDAC GEMMs cause embryonic, pancreas-wide activation or loss of driver alleles, neither of which reflects the cognate human disease scenario. The advent of CRISPR/Cas9 based gene editing can potentially circumvent many of the aforementioned shortcomings of conventional breeding schema, but ensuring the efficiency of gene editing in vivo remains a challenge. Here we have developed a pipeline for generating PDAC GEMMs of complex genotypes with high efficiency using a single "workhorse" mouse strain expressing Cas9 in the adult pancreas under a p48 promoter. Using adeno-associated virus (AAV) mediated delivery of multiplexed guide RNAs (sgRNAs) to the adult murine pancreas of p48-Cre; LSL-Cas9 mice, we confirm our ability to express an oncogenic Kras G12D allele through homology-directed repair (HDR), in conjunction with CRISPR-induced disruption of cooperating alleles (Trp53, Lkb1 and Arid1A). The resulting GEMMs demonstrate a spectrum of precursor lesions (pancreatic intraepithelial neoplasia [PanIN] or Intraductal papillary mucinous neoplasm [IPMN] with eventual progression to PDAC. Next generation sequencing of the resulting murine PDAC confirms HDR of oncogenic KrasG12D allele at the endogenous locus, and insertion deletion ("indel") and frameshift mutations of targeted tumor suppressor alleles. By using a single "workhorse" mouse strain and optimal AAV serotype for in vivo gene editing with combination of driver alleles, we present a facile autochthonous platform for interrogation of the PDAC genome.

GNASR201C Induces Pancreatic Cystic Neoplasms in Mice That Express Activated KRAS by Inhibiting YAP1 Signaling.

BACKGROUND & AIMS: Mutations at hotspots in GNAS, which encodes stimulatory G-protein, α subunits, are detected in approximately 60% of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas. We generated mice with KRAS-induced IPMNs that also express a constitutively active form of GNAS in pancreas and studied tumor development. METHODS: We generated p48-Cre; LSL-KrasG12D; Rosa26R-LSL-rtTA-TetO-GnasR201C mice (Kras;Gnas mice); pancreatic tissues of these mice express activated KRAS and also express a mutant form of GNAS (GNASR201C) upon doxycycline administration. Mice that were not given doxycycline were used as controls, and survival times were compared by Kaplan-Meier analysis. Pancreata were collected at different time points after doxycycline administration and analyzed by histology. Pancreatic ductal adenocarcinomas (PDACs) were isolated from mice and used to generate cell lines, which were analyzed by reverse transcription polymerase chain reaction, immunoblotting, immunohistochemistry, and colony formation and invasion assays. Full-length and mutant forms of yes-associated protein (YAP) were expressed in PDAC cells. IPMN specimens were obtained from 13 patients with IPMN undergoing surgery and analyzed by immunohistochemistry. RESULTS: All Kras;Gnas mice developed pancreatic cystic lesions that resemble human IPMNs; the grade of epithelial dysplasia increased with time. None of the control mice developed cystic lesions. Approximately one third of Kras;Gnas mice developed PDACs at a median of 30 weeks after doxycycline administration, whereas 33% of control mice developed PDACs. Expression of GNASR201C did not accelerate the development of PDACs compared with control mice. However, the neoplasms observed in Kras;Gnas mice were more differentiated, and expressed more genes associated with ductal phenotypes, than in control mice. PDACs isolated from Kras;Gnas mice had activation of the Hippo pathway; in cells from these tumors, phosphorylated YAP1 was sequestered in the cytoplasm, and this was also observed in human IPMNs with GNAS mutations. Sequestration of YAP1 was not observed in PDAC cells from control mice. CONCLUSIONS: In mice that express activated KRAS in the pancreas, we found expression of GNASR201C to cause development of more differentiated tumors, with gene expression pattern associated with the ductal phenotype. Expression of mutant GNAS caused phosphorylated YAP1 to be sequestered in the cytoplasm, altering tumor progression.

Long-term outcomes after total pancreatectomy: special reference to survivors' living conditions and quality of life.

BACKGROUND: Although recent studies have confirmed the safety of total pancreatectomy (TP), appropriate selection of patients for TP has not been well documented. Because patients require lifelong medical treatment and self-management of pancreatic insufficiency after TP, indications for TP should be determined carefully according not only to disease factors but also to the social background of patients. We aimed to clarify long-term outcomes after TP, including the living conditions and quality of life (QoL), of surviving patients. METHODS: Medical records of 44 consecutive patients who underwent TP between 1990 and 2013 were reviewed retrospectively; 25 survivors completed cross-sectional clinical surveys and responded to a questionnaire about QoL using Short Form 36v2. RESULTS: Prevalence of morbidity and mortality after TP was 32 and 5 %, respectively. Postoperative complications occurred more frequently in elderly patients than in young patients (48 vs. 14 %; P = 0.02); however, there was no significant difference in mortality, postoperative hospital stay, or survival. Twenty-four of 25 survivors (96 %) could manage pancreatogenic diabetes by themselves, and the median level of glycosylated hemoglobin was 7.4 %. Although one-third of patients after TP complained of diarrhea and the QoL scores of patients with diarrhea were lower than those of patients without diarrhea, QoL scores after TP were virtually comparable with those of the national population, even in elderly patients. CONCLUSIONS: TP can be performed safely, even in elderly patients. QoL after TP seems to be acceptable if patients are capable of self-management.

Treatment strategy for main duct intraductal papillary mucinous neoplasms of the pancreas based on the assessment of recurrence in the remnant pancreas after resection: a retrospective review.

OBJECTIVES: To clarify the recurrence pattern after resection of main duct intraductal papillary mucinous neoplasms (MD-IPMNs) using molecular analyses and determine the most adequate treatment strategy. BACKGROUND: The most appropriate resection line for MD-IPMNs remains an unresolved issue. METHODS: Medical records of 56 patients with pancreatectomy were retrospectively reviewed. Histological subtypes and Kras/GNAS mutations were assessed in patients with recurrence in the remnant pancreas. RESULTS: Forty-nine patients underwent partial pancreatectomy and 7 underwent total pancreatectomy. Thirty-six patients (64%) had malignant MD-IPMNs. Recurrence was observed in 7 of 49 patients (14%), including 6 with malignant IPMNs and 1 with pancreatic ductal adenocarcinoma, all of whom underwent remnant pancreatectomy. The cumulative disease-specific survival rate of patients with pancreatic recurrence was greater than that of patients with extrapancreatic recurrence (P < 0.001). Although the pancreatic margin status at the initial operation did not affect the pancreatic recurrence rate, all 4 recurrent IPMNs examined had histological subtypes and Kras/GNAS mutations identical to those of the initial lesions. Four patients experienced recurrence in the remnant pancreas or systemic recurrence after resection of high-grade dysplasia of MD-IPMN. Three of the 56 patients had concomitant pancreatic ductal adenocarcinomas and MD-IPMNs. CONCLUSIONS: One-step total pancreatectomy can be avoided, and remnant total pancreatectomy would lead to favorable outcomes even in patients with pancreatic recurrence, some cases of which seem to involve residual lesions. Postoperative surveillance of high-grade dysplasia should be performed as if malignant, and close attention should be paid to the occurrence of concomitant pancreatic ductal adenocarcinomas in patients with MD-IPMNs.

Profiling of autoantibodies in sera of pancreatic cancer patients.

BACKGROUND: Although autoantibodies to cancer antigens are candidates for biomarkers, no comprehensive studies to detect cancer-specific antibodies have been performed. This study identified autoantibodies in the sera of pancreatic cancer (PC) patients using proteomics based on a wheat germ cell-free protein production system. METHODS: We constructed a biotinylated protein library of 2,183 genes. Interactions between biotinylated proteins and serum antibodies were detected by AlphaScreen® assay. Relative luminescence signals of each protein in 37 PC patients and 20 healthy controls were measured, and their sensitivity and specificity for PC were calculated. RESULTS: Luminescence signals of nine proteins were significantly higher than those of healthy controls, with calcium and integrin binding 1 (CIB1) protein showing the greatest significance (p = 0.002). Sensitivity, specificity, positive predictive value and negative predictive value of CIB1 autoantibody alone for PC were 76, 70, 82, and 61 %, respectively, and 97, 35, 74, and 88 %, respectively, when the four most significant proteins were combined. Presence of these autoantibodies did not vary significantly with other clinicopathological characteristics. CONCLUSION: Several autoantibodies, including CIB1, are potential biomarkers for PC.

Role of pancreatic juice cytology in the preoperative management of intraductal papillary mucinous neoplasm of the pancreas in the era of international consensus guidelines 2012.

BACKGROUND: Routine endoscopic retrograde pancreatography (ERP) for pancreatic juice cytology (PJC) during management of intraductal papillary mucinous neoplasm (IPMN) is not recommended in the international consensus guidelines 2012. The aim of the present study was to investigate the roles of PJC in relation to the new stratification of clinical findings in the consensus guidelines 2012. METHODS: Medical records of 70 consecutive patients who underwent preoperative PJC, subsequent pancreatectomy, and a pathological diagnosis of IPMN were reviewed. Diagnostic ability of PJC to detect malignant lesions was calculated by the stratification of clinical findings. RESULTS: Forty patients had malignant lesions, including 29 with malignant IPMN, 10 with concomitant pancreatic adenocarcinoma, and one with both. Accuracies of PJC in all 70 patients and in 59 patients with IPMN alone were 77 and 80 %, respectively. The sensitivity and accuracy of PJC in patients with "worrisome features" were 100 and 94 %, respectively. Eight of 11 patients with concomitant pancreatic adenocarcinoma had non-malignant IPMN without risk factors, and 3 significant lesions could be diagnosed only by ERP/PJC. In addition, the management plan based on imaging study changed from observation to resection in two patients who had the single "worrisome feature" of branch duct IPMN and positive PJC results. As a result, PJC altered the management plan in 5 patients. CONCLUSIONS: Pancreatic juice cytology potentially has important roles to determine the adequate treatment choice in patients with IPMNs with "worrisome features," and to detect significant lesions that could not be detected by other imaging modalities.

Prediction of Pancreatic Fistula by Preoperatively Assessable Factors; Retrospective Review of Unified Operations by Single Surgeon.

BACKGROUND/AIMS: This retrospective study was conducted to find preoperatively assessable risk factors for postoperative pancreatic fistula (POPF) in patients undergoing laparoscopic distal pancreatectomy (LDP) using a slow compression method with a stapler, which we call pen-firing compression (PFC). METHODOLOGY: Fifty-two patients underwent LDP, of whom 42 underwent PFC for pancreatic division using a stapler. The relationship between preoperatively assessable factors and the incidence of clinical POPF was statistically analyzed. RESULTS: Overall rate of POPF was 7.1% in 42 patients. Univariate analysis showed that greater BMI (p = 0.004) and thicker pancreatic stump (0.0022) were significant risk factors for POPF. BMI and stump thickness remained significant (P < 0.0001, P < 0.0001) by multivariate analysis. Cutoff points estimated by ROC curve were 27 kg/m2 for BMI and 27 mm for stump thickness. CONCLUSIONS: High BMI value and thick pancreatic stump are significant risk factors for POPF after LDP. Alternative treatment of the pancreatic stump may prevent POPF in high-risk patients.

Role of ERCP in the era of EUS-FNA for preoperative cytological confirmation of resectable pancreatic ductal adenocarcinoma.

PURPOSE: In patients with pancreatic ductal carcinoma (PDAC), EUS-FNA carries a risk of cancer seeding. To avoid this risk, we attempted to obtain preoperative cytological confirmation of adenocarcinoma by ERCP. The aim of this study was to assess the validity of our diagnostic strategy. METHODS: The medical records of 124 consecutive patients who were investigated for potentially resectable PDAC were retrospectively reviewed, and the ability to detect adenocarcinoma by ERCP was evaluated. RESULTS: ERCP was performed in 115 patients, 69 of whom had positive cytology results. Thirty-four patients underwent EUS-FNA, 29 of whom had positive cytology results. A total of 98 patients (79 %), therefore, had preoperative cytological confirmation of adenocarcinoma, which was more frequent in patients with lesions of the head of the pancreas than in those with lesions of the body or tail of the pancreas. The postoperative pathological diagnosis demonstrated malignant pancreatic neoplasms in 122 patients (98 %), including 111 with PDAC. EUS-FNA did not affect the rate of postoperative peritoneal dissemination. CONCLUSIONS: Our strategy using ERCP as the initial diagnostic modality for obtaining cytological confirmation of potentially resectable PDAC seems to be adequate, yielding a high rate of positive cytology, especially in cases with tumors of the head of the pancreas.

MicroRNA-20a in extracellular vesicles derived from duodenal fluid is a possible biomarker for pancreatic ductal adenocarcinoma.

Background: Pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate owing to its late diagnosis and aggression. In addition, there are relatively few minimally invasive screening methods for the early detection of PDAC, making the identification of biomarkers for this disease a critical priority. Recent studies have reported that microRNAs in extracellular vesicles (EV-miRs) from bodily fluids can be useful for the diagnosis of PDACs. Given this, we designed this study to evaluate the utility of cancer EVs extracted from duodenal fluid (DF) and their resident EV-miRs as potential biomarkers for the detection of PDAC. Methods: EV-miRs were evaluated and identified in the supernatants of various pancreatic cancer cell lines (Panc-1, SUIT2, and MIAPaca2), human pancreatic duct epithelial cells, and the DF from patients with PDAC and healthy controls. EVs were extracted using ultracentrifugation and the relative expression of EV-miR-20a was quantified. Results: We collected a total of 34 DF samples (27 PDAC patients and seven controls) for evaluation and our data suggest that the relative expression levels of EV-miR-20a were significantly higher in patients with PDAC than in controls (p = 0.0025). In addition, EV-miR-20a expression could discriminate PDAC from control patients regardless of the location of the tumor with an area under the curve values of 0.88 and 0.88, respectively. Conclusions: We confirmed the presence of EVs in the DF and suggest that the expression of EV-miR-20a in these samples may act as a potential diagnostic biomarker for PDAC.

Is preoperative pancreatic juice cytology useful for determining therapeutic strategies for patients with intraductal papillary mucinous neoplasm of the pancreas?

BACKGROUND: We compared the results of preoperative pancreatic juice cytology (PJC) and final pathological diagnosis after resection in patients who underwent resection of intraductal papillary mucinous neoplasm (IPMN) of the pancreas to determine whether preoperative PJC can help determine therapeutic strategies. METHODS: Of 1130 patients who underwent surgical resection IPMN at 11 Japanese tertiary institutions, the study included 852 patients who underwent preoperative PJC guided by endoscopic retrograde cholangiopancreatography (ERCP). RESULTS: The accuracy of preoperative PJC for differentiation between cancerous and noncancerous lesions were 55% for IPMN overall; 59% for the branch duct type; 49% for the main pancreatic duct type; 53% for the mixed type, respectively. On classifying IPMN according to the diameters of the mural nodule (MN) and main pancreatic duct (MPD), the corresponding values for diagnostic performance were 40% for type 1 (MN ≥5 mm and MPD ≥ 10 mm); 46% for type 2 (MN ≥5 mm and MPD < 10 mm); 61% for type 3 (MN < 5 mm and MPD ≥ 10 mm); 72% for type 4 (MN < 5 mm and MPD < 10 mm), respectively. CONCLUSIONS: PJC in IPMN is not a recommended examination because of its low overall sensitivity and no significant difference in diagnostic performance by type, location, or subclassification. Although the sensitivity is low, the positive predictive value is high, so we suggest that pancreatic juice cytology be performed only in cases where the patient is not sure about surgery.

Intraductal papillary mucinous neoplasms of the pancreas with distinct pancreatic ductal adenocarcinomas are frequently of gastric subtype.

OBJECTIVE: To identify a high-risk group of patients with pancreatic ductal adenocarcinoma (PDAC), independently arising in the pancreas with intraductal papillary mucinous neoplasm (IPMN), using histopathologic subtypes. BACKGROUND: Pathologic features of IPMN with distinct PDAC, including histopathologic subtypes of IPMN and PDAC phenotypes, have not been well characterized. Mucin expression patterns and the mutational status of GNAS and KRAS are useful to explore the relationship between these 2 lesion types. METHODS: Clinicopathologic data of 179 resected IPMNs and 180 resected PDACs without IPMNs as a control group were reviewed. IPMNs were classified into 4 grades (low-grade, intermediate-grade, high-grade dysplasia, and an associated invasive carcinoma) and 4 subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). The expression of MUC1, MUC2, MUC5AC, MUC6, and CDX2 was investigated by immunohistochemistry in IPMNs and PDACs with and without IPMNs. The mutational status of GNAS and KRAS was evaluated by cycle sequencing in PDACs and pre-/coexisting IPMNs. RESULTS: Twenty-six synchronous or metachronous PDACs were identified in 20 patients (11.2%) with IPMNs. Occurrence of concomitant PDACs was more frequently observed in gastric-type IPMNs (18/110, 16.4%) compared with intestinal (1/49, 2.0%), pancreatobiliary (1/17, 5.9%), or oncocytic-type (0/3, 0%) (P = 0.047). Both PDACs with and without IPMNs were frequently positive for MUC1, MUC5AC, and MUC6 expression, as assessed by immunohistochemistry, but were negative for MUC2 and CDX2. The mucin-staining patterns were similar to those of invasive tubular adenocarcinoma arising from gastric-type IPMNs. Mutation of GNAS within codon 201 was not detected in PDACs and gastric-type IPMNs, whereas most of these exhibited KRAS mutations. However, the R201H GNAS mutation was detected in 1 intestinal-type IPMN with distinct PDAC. CONCLUSIONS: Mucin expression patterns demonstrate that PDAC without GNAS mutations of an aggressive phenotype frequently arise in the pancreas with benign gastric-type IPMN in the absence of GNAS mutations.