Is surgical resection justified for pancreatic ductal adenocarcinoma with distant abdominal organ metastasis? A position paper by experts in pancreatic surgery at the Joint Meeting of the International Association of Pancreatology (IAP) & the Japan Pancreas Society (JPS) 2022 in Kyoto

Pancreatic ductal adenocarcinoma (PDAC) is a typical refractory malignancy, and many patients have distant organ metastases at diagnosis, such as liver metastasis and peritoneal dissemination. The standard treatment for unresectable PDAC with distant organ metastasis (UR-M) is chemotherapy, but the prognosis remained poor. However, with recent dramatic developments in chemotherapy, the prognosis has gradually improved, and some patients have experienced marked shrinkage or disappearance of their metastatic lesions. With this trend, attempts have been made to resect a small number of metastases (so-called oligometastases) in combination with the primary tumor or to resect the primary and metastatic tumor in patients with a favorable response to anti-cancer treatment after a certain period of time (so-called conversion surgery). An international consensus meeting on surgical treatment for UR-M PDAC was held during the Joint Congress of the 26th Meeting of the International Association of Pancreatology (IAP) and the 53rd Annual Meeting of the Japan Pancreas Society (JPS) in Kyoto in July 2022. The presenters showed their indications for and results of surgical treatment for UR-M PDAC and discussed their advantages and disadvantages with the experts. Although these reports were limited to a small number of patients, findings suggest that these surgical treatments for patients with UR-M PDAC who have had a significant response to chemotherapy may contribute to a prognosis of prolonged survival. We hope that this article summarizing the discussion and agreements at the meeting will serve as the basis for future trials and guidelines.

"Conversion surgery" for locally advanced pancreatic cancer: A position paper by the study group at the joint meeting of the International Association of Pancreatology (IAP) & Japan Pancreas Society (JPS) 2022

Locally advanced pancreatic cancer (LAPC), which progresses locally and surrounds major vessels, has historically been deemed unresectable. Surgery alone failed to provide curative resection and improve overall survival. With the advancements in treatment, reports have shown favorable results in LAPC after undergoing successful chemotherapy therapy or chemoradiation therapy followed by surgical resection, so-called "conversion surgery", at experienced high-volume centers. However, recognizing significant regional and institutional disparities in the management of LAPC, an international consensus meeting on conversion surgery for LAPC was held during the Joint Congress of the 26th Meeting of the International Association of Pancreatology (IAP) and the 53rd Annual Meeting of Japan Pancreas Society (JPS) in Kyoto in July 2022. During the meeting, presenters reported the current best multidisciplinary practices for LAPC, including preoperative modalities, best systemic treatment regimens and durations, procedures of conversion surgery with or without vascular resections, biomarkers, and genetic studies. It was unanimously agreed among the experts in this meeting that "cancer biology is surpassing locoregional anatomical resectability" in the era of effective multiagent treatment. The biology of pancreatic cancer has yet to be further elucidated, and we believe it is essential to improve the treatment outcomes of LAPC patients through continued efforts from each institution and more international collaboration. This article summarizes the agreement during the discussion amongst the experts in the meeting. We hope that this will serve as a foundation for future international collaboration and recommendations for future guidelines.

Propensity Score Matching Analysis of the Safety of Completion Total Pancreatectomy for Remnant Pancreatic Tumors Versus that of Initial Total Pancreatectomy for Primary Pancreatic Tumors

BACKGROUND

The safety and feasibility of completion total pancreatectomy (TP) for remnant pancreatic neoplasms remain controversial and are rarely compared with that of initial TP. Thus, we aimed to compare the safety of these two procedures inducing a pancreatic state.

METHODS

Patients who underwent TP for pancreatic neoplasms between 2006 and 2018 at our institution were included in this study. Tumor pathologies were classified into three subgroups according to survival curves. We used 1:1 propensity score matching (PSM) to analyze age, sex, Charlson Comorbidity Index, and tumor stage. Finally, we analyzed the primary outcome Clavien-Dindo classification (CDC) grade, risks of other safety-related outcomes, and the survival rate of patients with invasive cancer.

RESULTS

Of 54 patients, 16 underwent completion TP (29.6%) and 38 (70.4%) underwent initial TP. Before PSM analysis, age and Charlson Comorbidity Index were significantly higher, and T category and stage were significantly lower for the completion TP group. Upon PSM analysis, these two groups were equivalent in CDC grade [initial TP vs. completion TP: 71.4% (10/14) vs. 78.6% (11/14); p = 0.678] and other safety-related outcomes. Additionally, while the overall survival and recurrence-free survival of patients with invasive cancer were not significantly different between these two groups, the T category and stage tended to be remarkably severe in the initial TP group.

CONCLUSIONS

PSM analysis for prognostic factors showed that completion TP and initial TP have similar safety-related outcomes that can be used as a decision-making reference in the surgery of pancreatic tumors.

Mixed acinar-neuroendocrine carcinoma of the pancreas with positive for microsatellite instability: a case report and review of the literature

BACKGROUND

Mixed acinar-neuroendocrine carcinoma (MANEC) of the pancreas is a rare tumor. We report a case of successful surgical resection of expansively growing MANEC of the pancreas with microsatellite instability (MSI)-high.

CASE PRESENTATION

The patient was an asymptomatic 65-year-old male. A computed tomography (CT) scan for a follow-up after treatment of pneumonia incidentally revealed a hypoenhancing 12-cm expansively growing tumor in the pancreatic body. An endoscopic ultrasound-guided fine-needle aspiration of the tumor suggested the diagnosis of MANEC. We performed distal pancreatectomy with combined resection of the spleen, left adrenal gland, transverse colon, small bowel, and stomach. The intraoperative findings showed that the tumor was capsular and was in contact with the SMA, SMV, and CA; however, obvious infiltration of these vessels was not observed..Pathological findings indicated MANEC with MSI-high. Among mismatch repair (MMR) gene proteins, PMS2 was lost and MLH1, MSH2, and MSH6 were retained. The tumor recurred 5 months after surgery. The patient was treated with gemcitabine plus nab-paclitaxel followed by pembrolizumab, which did not show objective response.

DISCUSSION

This is the first report investigating MSI and MMR in MANEC. Standard chemotherapy has not been established for MANEC. Detection of MSI-high is essential since PD-1 monoclonal antibodies for MSI-high cases might be one of the good treatment options. Herein, we discuss the various cytomorphologic and clinical features of MANEC and present a brief review of the literatures.

CONCLUSIONS

The accumulation of data from additional cases is necessary to further evaluate this type of carcinoma and provide a standardized optimal therapy for MANEC.

Study protocol for a multi-institutional prospective surveillance study among kindreds with familial pancreatic cancer and individuals with hereditary pancreatic cancer syndrome: The Diamond Study

BACKGROUND

Family history of pancreatic cancer (PC) and some hereditary cancer syndromes are risk factors for PC. Previous studies suggest that conducting surveillance for kindreds at high risk for familial PC may be useful for diagnoses at the stage where resections can still be implemented; however, there is insufficient evidence linking surveillance and increased rates of resectable PC.

METHODS

We launched a surveillance study for kindreds with familial PC and individuals with hereditary PC syndrome, titled the "Diamond Study," in June 2020. This Japanese national multi-institutional prospective intervention study has been initiated to conduct evaluations within a prospective clinical trial format.

RESULTS

The primary endpoint is the fraction of patients with resectable PC among patients with PC found through surveillance interventions. Endoscopic ultrasound and magnetic resonance imaging combined with magnetic resonance cholangiopancreatography will be performed alternatively every 6 months for up to 15 years, with 400 as the predicted number of registered participants and a predicted registration period of 10 years.

CONCLUSION

We intend to scientifically prove the usefulness of surveillance for kindreds with familial PC and individuals with hereditary PC syndrome to improve PC prognoses.

Postpancreatectomy Acute Pancreatitis (PPAP): Definition and Grading From the International Study Group for Pancreatic Surgery (ISGPS)

OBJECTIVE

The ISGPS aimed to develop a universally accepted definition for PPAP for standardized reporting and outcome comparison.

BACKGROUND

PPAP is an increasingly recognized complication after partial pancreatic resections, but its incidence and clinical impact, and even its existence are variable because an internationally accepted consensus definition and grading system are lacking.

METHODS

The ISGPS developed a consensus definition and grading of PPAP with its members after an evidence review and after a series of discussions and multiple revisions from April 2020 to May 2021.

RESULTS

We defined PPAP as an acute inflammatory condition of the pancreatic remnant beginning within the first 3 postoperative days after a partial pancreatic resection. The diagnosis requires (1) a sustained postoperative serum hyperamylasemia (POH) greater than the institutional upper limit of normal for at least the first 48 hours postoperatively, (2) associated with clinically relevant features, and (3) radiologic alterations consistent with PPAP. Three different PPAP grades were defined based on the clinical impact: (1) grade postoperative hyperamylasemia, biochemical changes only; (2) grade B, mild or moderate complications; and (3) grade C, severe life-threatening complications.

DISCUSSIONS

The present definition and grading scale of PPAP, based on biochemical, radiologic, and clinical criteria, are instrumental for a better understanding of PPAP and the spectrum of postoperative complications related to this emerging entity. The current terminology will serve as a reference point for standard assessment and lend itself to developing specific treatments and prevention strategies.

Impact of neoadjuvant intensity-modulated radiation therapy on borderline resectable pancreatic cancer with arterial abutment; a prospective, open-label, phase II study in a single institution

Background

Borderline resectable pancreatic cancer (BRPC) is a category of pancreatic cancer that is anatomically widely spread, and curative resection is uncommon with upfront surgery. Intensity-modulated radiation therapy (IMRT) is a form of radiation therapy that delivers precise radiation to a tumor while minimizing the dose to surrounding normal tissues. Here, we conducted a phase 2 study to estimate the curability and efficacy of neoadjuvant chemoradiotherapy using IMRT (NACIMRT) for patients with BRPC with arterial abutment (BRPC-A).

Methods

A total of 49 BRPC-A patients were enrolled in this study and were treated at our hospital according to the study protocol between June 2013 and March 2021. The primary endpoint was microscopically margin-negative resection (R0) rates and we subsequently analyzed safety, histological effect of the treatment as well as survivals among patients with NACIMRT.

Results

Twenty-nine patients (59.2%) received pancreatectomy after NACIMRT. The R0 rate in resection patients was 93.1% and that in the whole cohort was 55.1%. No mortality was encountered. Local therapeutic effects as assessed by Evans classification showed good therapeutic effect (Grade 1, 3.4%; Grade 2a, 31.0%; Grade 2b, 48.3%; Grade 3, 3.4%; Grade 4, 3.4%). Median disease-free survival was 15.5 months. Median overall survival in the whole cohort was 35.1 months. The only independent prognostic pre-NACIMRT factor identified was serum carbohydrate antigen 19–9 (CA19-9) > 400 U/ml before NACIMRT.

Conclusions

NACIMRT showed preferable outcome without significant operative morbidity for BRPC-A patients. NACIMRT contributes to good local tumor control, but a high initial serum CA19-9 implies poor prognosis even after neoadjuvant treatment.

Trial Registration

UMIN-CTR Clinical Trial: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000011776

Registration number: UMIN000010113.

Date of first registration: 01/03/2013,

Preoperative risk stratification of lymph node metastasis for non-functional pancreatic neuroendocrine neoplasm: An international dual-institutional study

BACKGROUND

/Objectives: Although the presence of lymph node metastasis (LNM) defines malignant potential, preoperative prediction of LNM has not been established for non-functional pancreatic neuroendocrine neoplasm (NF-PNEN). We sought to develop a prediction system using only preoperatively available factors that would stratify the risk of LNM for NF-PNEN.

METHODS

We retrospectively reviewed patients who underwent R0/1 resection of NF-PNEN at Kyoto University (2007-2019) and the University of California, San Francisco (2010-2019). Risk stratification of LNM was developed using preoperative factors by the logistic regression analysis. Long-term outcomes were compared across the risk groups.

RESULTS

A total of 131 patients were included in this study. Lymph nodes were pathologically examined in 116 patients, 23 (20%) of whom had LNM. Radiological tumor size [1.5-3.5 cm (odds ratio: 13.5, 95% confidence interval: 1.77-398) and >3.5 cm (72.4, 9.06-2257) against ≤1.5 cm], <50% cystic component (8.46 × 10^6, 1.68 × 10^106-), and dilatation of main pancreatic duct ≥5 mm (31.2, 3.94-702) were independently associated with LNM. When patients were classified as the low-risk (43 patients), intermediate-risk (44 patients), and high-risk groups (29 patients), proportions of LNM differed significantly across the groups (0%, 14%, and 59%, respectively). Recurrence-free survival (RFS) of the low- and intermediate-risk groups were significantly better than that of the high-risk group (5-year RFS rates of 92.2%, 85.4%, and 47.1%, respectively).

CONCLUSIONS

The prediction system using preoperative radiological factors stratifies the risk of LNM for NF-PNEN. This stratification helps to predict malignant potential and determine the surgical procedure and necessity of regional lymphadenectomy.

International expert consensus on precision anatomy for minimally invasive pancreatoduodenectomy: PAM-HBP surgery project

BACKGROUND

The anatomical structure around the pancreatic head is very complex and it is important to understand its precise anatomy and corresponding anatomical approach to safely perform minimally invasive pancreatoduodenectomy (MIPD). This consensus statement aimed to develop recommendations for elucidating the anatomy and surgical approaches to MIPD.

METHODS

Studies identified via a comprehensive literature search were classified using the Scottish Intercollegiate Guidelines Network method. Delphi voting was conducted after experts had drafted recommendations, with a goal of obtaining >75% consensus. Experts discussed the revised recommendations with the validation committee and an international audience of 384 attendees. Finalized recommendations were made after a second round of online Delphi voting.

RESULTS

Three clinical questions were addressed, providing six recommendations. All recommendations reached at least a consensus of 75%. Preoperatively evaluating the presence of anatomical variations and superior mesenteric artery (SMA) and superior mesenteric vein (SMV) branching patterns was recommended. Moreover, it was recommended to fully understand the anatomical approach to SMA and intraoperatively confirm the SMA course based on each anatomical landmark before initiating dissection.

CONCLUSIONS

MIPD experts suggest that surgical trainees perform resection based on precise anatomical landmarks for safe and reliable MIPD.

International Expert Consensus on Precision Anatomy for minimally invasive distal pancreatectomy: PAM-HBP Surgery Project

BACKGROUND

Surgical views with high resolution and magnification have enabled us to recognize the precise anatomical structures that can be used as landmarks during minimally invasive distal pancreatectomy (MIDP). This study aimed to validate the usefulness of anatomy-based approaches for MIDP before and during the Expert Consensus Meeting: Precision Anatomy for Minimally Invasive HBP Surgery (February 24, 2021).

METHODS

Twenty-five international MIDP experts developed clinical questions regarding surgical anatomy and approaches for MIDP. Studies identified via a comprehensive literature search were classified using Scottish Intercollegiate Guidelines Network methodology. Online Delphi voting was conducted after experts had drafted the recommendations, with the goal of obtaining >75% consensus. Experts discussed the revised recommendations in front of the validation committee and an international audience of 384 attendees. Finalized recommendations were made after a second round of online Delphi voting.

RESULTS

Four clinical questions were addressed, resulting in 10 recommendations. All recommendations reached at least a 75% consensus among experts.

CONCLUSIONS

The expert consensus on precision anatomy for MIDP has been presented as a set of recommendations based on available evidence and expert opinions. These recommendations should guide experts and trainees in performing safe MIDP and foster its appropriate dissemination worldwide.

Visualization of stem cell activity in pancreatic cancer expansion by direct lineage tracing with live imaging

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. Although rigorous efforts identified the presence of 'cancer stem cells (CSCs)' in PDAC and molecular markers for them, stem cell dynamics in vivo have not been clearly demonstrated. Here we focused on Doublecortin-like kinase 1 (Dclk1), known as a CSC marker of PDAC. Using genetic lineage tracing with a dual-recombinase system and live imaging, we showed that Dclk1⁺ tumor cells continuously provided progeny cells within pancreatic intraepithelial neoplasia, primary and metastatic PDAC, and PDAC-derived spheroids in vivo and in vitro. Furthermore, genes associated with CSC and epithelial mesenchymal transition were enriched in mouse Dclk1⁺ and human DCLK1-high PDAC cells. Thus, we provided direct functional evidence for the stem cell activity of Dclk1⁺ cells in vivo, revealing the essential roles of Dclk1⁺ cells in expansion of pancreatic neoplasia in all progressive stages.

Impact of vascular abnormality on contrast-enhanced CT and high C-reactive protein levels on postoperative pancreatic hemorrhage after pancreaticoduodenectomy: A multi-institutional, retrospective analysis of 590 consecutive cases

BACKGROUND

/Objectives: This study aimed to elucidate the efficacy of CT findings and perioperative characteristics to predict post-pancreatectomy hemorrhage (PPH): a critical complication after pancreaticoduodenectomy.

METHODS

The records of 590 consecutive patients who underwent pancreaticoduodenectomy at three institutes between 2012 and 2018 were included. The presence of a vascular wall abnormality or ascites with high density (vascular abnormality) on postoperative day (POD) 5-10 contrast-enhanced CT (early CT), perioperative characteristics, and any PPH or pseudoaneurysm formation (PPH events) were analyzed through a multivariate analysis.

RESULTS

PPH events occurred in 48 out of 590 patients (8%). The vascular abnormality on early CT and the C-reactive protein (CRP) value on POD 3 were independent risk factors for PPH events after POD5 (vascular abnormality: odds ratio 6.42, p = 0.001; CRP on POD 3: odds ratio 1.17, p = 0.016). The sensitivity of vascular abnormality for PPH events was 24% (7/29), and the positive predictive value was 30% (7/23). The combination of vascular abnormality and a high CRP value (≥15.5 mg/dL) on postoperative day 3 had a higher positive predictive value of 64% (7/11) than the vascular abnormality alone. None of the seven PPH events that occurred more than one month after surgery were foreseen via early CT.

CONCLUSION

The combination of vascular abnormality and high CRP value was associated with increasing risk of PPH events after pancreaticoduodenectomy, but the low sensitivity of early CT must be noted as an important shortcoming. The normal findings on early CT could not eliminate the risk of late PPH.

Left-posterior approach for artery-first en bloc resection in laparoscopic distal pancreatectomy for left-sided pancreatic cancer

PURPOSE

We describe a "left-posterior approach" in which the important steps in laparoscopic distal pancreatectomy (LDP) for left-sided pancreatic cancer are accomplished in the direction caudal and dorsal to the pancreas.

METHODS

The patients who underwent LDP with a left-posterior approach at our hospital from January 2016 to April 2020 were reviewed to evaluate the short-term postoperative outcomes. In LDP, we first dissected retroperitoneal tissues above the left renal vein and superior mesenteric artery, yielding the mobilization of the pancreatic body widely. Then, the splenic artery was divided behind the ventrally lifted pancreas as an artery-first approach. The regional lymphadenectomy was performed in an en bloc manner consecutively in the same operative field. The neck of the pancreas was transected with a linear stapler after mobilization of the spleen.

RESULTS

In nine patients (five men and four women) aged 76 years (range: 64-82 years), the operative time was 398 min (276-482 min) with the estimated blood loss of 40 ml (0-80 ml). No patients developed grade B/C pancreatic fistula or delayed gastric emptying. Postoperative complications classified as grade III in the Clavien-Dindo classification occurred in one patient (abdominal abscess). The pathology confirmed R0 resection in all patients who had pancreatic cancer (n = 5), IPMNs (n = 3), and high-grade pancreatic intraepithelial neoplasia (PanIN) (n = 1). The number of retrieved lymph nodes was 35 (11-49).

CONCLUSION

The procedure with a left-posterior approach is a rational surgical technique in LDP for left-sided pancreatic cancer.

Robotic-assisted pancreaticoduodenectomy with vascular resection. Description of the surgical technique and analysis of early outcomes

BACKGROUND

Despite the potential benefits, the adoption of the minimally invasive surgery for the treatment of borderline resectable pancreatic cancer is still in the initial phase. We investigated the safety and feasibility of the robotic pancreaticoduodenectomy with venous resection/reconstruction (RPD SMV/PV).

METHODS

Since March 2013 to October 2019, a total of 73 RPD and 10 RPD SMV/PV were performed. The two groups were case-matched according to the preoperative characteristics.

RESULTS

Mean operative times and estimated blood loss were less in the RPD group in comparison to that in the RPD with SMV-PV group (525 vs 642 min, p = 0.003 and 290 vs 620 ml, p = 0.002, respectively). The mean length of hospital stay was similar in the RPD group in comparison to that in the RPD with SMV-PV group (10 days vs 13 days, p = 0.313). The two groups had similar overall postoperative morbidity rate (57.5% vs 60%, p = 0.686), although the severe complication rate was lower in the RPD group (11% vs 40%, p = 0.004).

CONCLUSIONS

RPD with SMV-PV is associated with increased operative time, estimated blood loss, higher major complication rate compared with RPD.

SETDB1 Inhibits p53-Mediated Apoptosis and Is Required for Formation of Pancreatic Ductal Adenocarcinomas in Mice

BACKGROUND & AIMS

SETDB1, a histone methyltransferase that trimethylates histone H3 on lysine 9, promotes development of several tumor types. We investigated whether SETDB1 contributes to development of pancreatic ductal adenocarcinoma (PDAC).

METHODS

We performed studies with Ptf1a^Cre; Kras^G12D; Setdb1^f/f, Ptf1a^Cre; Kras^G12D; Trp53^f/+; Setdb1^f/f, and Ptf1a^Cre; Kras^G12D; Trp53^f/f; Setdb1^f/f mice to investigate the effects of disruption of Setdb1 in mice with activated KRAS-induced pancreatic tumorigenesis, with heterozygous or homozygous disruption of Trp53. We performed microarray analyses of whole-pancreas tissues from Ptf1a^Cre; Kras^G12D; Setdb1^f/f, and Ptf1a^Cre; Kras^G12D mice and compared their gene expression patterns. Chromatin immunoprecipitation assays were performed using acinar cells isolated from pancreata with and without disruption of Setdb1. We used human PDAC cells for SETDB1 knockdown and inhibitor experiments.

RESULTS

Loss of SETDB1 from pancreas accelerated formation of premalignant lesions in mice with pancreata that express activated KRAS. Microarray analysis revealed up-regulated expression of genes in the apoptotic pathway and genes regulated by p53 in SETDB1-deficient pancreata. Deletion of Setdb1 from pancreas prevented formation of PDACs, concomitant with increased apoptosis and up-regulated expression of Trp53 in mice heterozygous for disruption of Trp53. In contrast, pancreata of mice with homozygous disruption of Trp53 had no increased apoptosis, and PDACs developed. Chromatin immunoprecipitation revealed that SETDB1 bound to the Trp53 promoter to regulate its expression. Expression of an inactivated form of SETDB1 in human PDAC cells with wild-type TP53 resulted in TP53-induced apoptosis.

CONCLUSIONS

We found that the histone methyltransferase SETDB1 is required for development of PDACs, induced by activated KRAS, in mice. SETDB1 inhibits apoptosis by regulating expression of p53. SETDB1 might be a therapeutic target for PDACs that retain p53 function.

Mitomycin C treatment improves pancreatic islet graft longevity in intraportal islet transplantation by suppressing proinflammatory response

The in vitro culture period prior to cell transplantation (i.e. pancreatic islet transplantation) enables cell modification and is thus advantageous. However, the islet preconditioning method has not been fully explored. Here we present a simple approach for islet preconditioning that uses the antibiotic mitomycin C (MMC), which has antitumor activity, to reduce islet immunogenicity and prevent proinflammatory events in an intraportal islet transplantation model. Freshly isolated mice islets were treated for 30 min with 10 μg/mL MMC or not, cultured for 20 h and transplanted into the livers of syngeneic or allogeneic diabetic mouse recipients. In the allogeneic model, MMC preconditioning significantly prolonged graft survival without requiring immunosuppressants. In vitro, MMC treatment suppressed the expression of proinflammatory cytokines in islet allografts, while immunohistochemical studies revealed the suppression of inflammatory cell infiltration into MMC-treated allografts relative to untreated allografts. Furthermore, MMC preconditioning significantly suppressed the mRNA expression of proinflammatory cytokines into the transplant site and induced the differentiation of regulatory T cells with the ability to suppress CD4⁺ T cell-mediated immune responses. In conclusion, islet preconditioning with MMC prolonged graft survival in an intraportal islet transplantation model by suppressing proinflammatory events and inducing potentially regulatory lymphocytes.

International consensus guidelines on surveillance for pancreatic cancer in chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club

BACKGROUND

Patients with chronic pancreatitis (CP) have an increased risk of pancreatic cancer. We present the international consensus guidelines for surveillance of pancreatic cancer in CP.

METHODS

The international group evaluated 10 statements generated from evidence on 5 questions relating to pancreatic cancer in CP. The GRADE approach was used to evaluate the level of evidence available per statement. The working group voted on each statement for strength of agreement, using a nine-point Likert scale in order to calculate Cronbach's alpha reliability coefficient.

RESULTS

In the following domains there was strong consensus: (1) the risk of pancreatic cancer in affected individuals with hereditary pancreatitis due to inherited PRSS1 mutations is high enough to justify surveillance; (2) the risk of pancreatic cancer in patients with CP associated with SPINK1 p. N34S is not high enough to justify surveillance; (3) surveillance should be undertaken in pancreatic specialist centers; (4) surveillance should only be introduced after the age of 40 years and stopped when the patient would no longer be suitable for surgical intervention. All patients with CP should be advised to lead a healthy lifestyle aimed at avoiding risk factors for progression of CP and pancreatic cancer. There was only moderate or weak agreement on the best methods of screening and surveillance in other types of environmental, familial and genetic forms of CP.

CONCLUSIONS

Patients with inherited PRSS1 mutations should undergo surveillance for pancreatic cancer, but the best methods for cancer detection need further investigation.

Management of the pancreatic transection plane after left (distal) pancreatectomy: Expert consensus guidelines by the International Study Group of Pancreatic Surgery (ISGPS)

BACKGROUND

The aim was to evaluate the various operative techniques and outcomes used to manage the pancreatic transection plane (or stump) during a left (distal) pancreatectomy and to develop expert consensus guidelines.

METHODS

Evidence-based, clinically relevant questions were discussed and then were circulated among members of the International Study Group of Pancreatic Surgery. After agreement on the questions and statements, voting in a 9-point Likert scale was used to gauge the level of objective support for each.

RESULTS

Studies using the International Study Group of Pancreatic Surgery definition of postoperative pancreatic fistula including 16 randomized trials were reviewed to generate a series of statements set into 14 domains. There was strong consensus in the following statements: there was no difference in the postoperative pancreatic fistula rate after left pancreatectomy between the handsewn and stapler techniques; a stapling technique could not be used in all cases of left pancreatectomy; the use of an energy-based tissue sealant or a chemical sealant device or combinations of these did not impact the postoperative pancreatic fistula rate; there was no difference in the postoperative pancreatic fistula rate between the open, laparoscopic, or robotic approaches; and there are 1 or more clinically important, patient-related risk factors associated with the postoperative pancreatic fistula rate. There was weak or conditional agreement on the use of prophylactic somatostatin analogs, stents, stump closure, stump anastomosis, and the role of abdominal drains.

CONCLUSION

Areas of strong consensus suggests a change in clinical practice and priority setting. Eight domains with lower agreement will require novel approaches and large multicenter studies to determine future key areas of practice.

International Consensus Guidelines for Risk Factors in Chronic Pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club

BACKGROUND

Chronic pancreatitis (CP) is a complex inflammatory disease with remarkably impaired quality of life and permanent damage of the pancreas. This paper is part of the international consensus guidelines on CP and presents the consensus on factors elevating the risk for CP.

METHODS

An international working group with 20 experts on CP from the major pancreas societies (IAP, APA, JPS, and EPC) evaluated 14 statements generated from evidence on four questions deemed to be the most clinically relevant in CP. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the level of evidence available per statement. To determine the level of agreement, the working group voted on the 14 statements for strength of agreement, using a nine-point Likert scale in order to calculate Cronbach's alpha reliability coefficient.

RESULTS

Strong consensus and agreement were obtained for the following statements: Alcohol, smoking, and certain genetic alterations are risk factors for CP. Past history, family history, onset of symptoms, and life-style factors including alcohol intake and smoking history should be determined. Alcohol consumption dose-dependently elevates the risk of CP up to 4-fold. Ever smokers, even smoking less than a pack of cigarettes per day, have an increased risk for CP, as compared to never smokers.

CONCLUSIONS

Both genetic and environmental factors can markedly elevate the risk for CP. Therefore, health-promoting lifestyle education and in certain cases genetic counselling should be employed to reduce the incidence of CP.

Usefulness of 18 F-FDG-PET/CT in the diagnosis and prediction of recurrence of pancreatic neuroendocrine neoplasms

BACKGROUND

Although ¹⁸ F-FDG-PET/CT is a widely used diagnostic tool for several malignancies, its efficacy in diagnosing pancreatic neuroendocrine tumors is reported to be controversial because of the short-term follow-up.

METHODS

We retrospectively compared demographics and pathological features between ¹⁸ F-FDG-positive and -negative diseases. Additionally, we evaluated whether the avidity of ¹⁸ F-FDG-PET/CT affected earlier recurrence after curative treatment of non-functioning tumors. The median duration of observation was 65.6 months.

RESULTS

Seventy-two patients were enrolled. ¹⁸ F-FDG-positive diseases were pathologically advanced and significantly associated with metastatic behavior. In a multivariate analysis, metastatic behavior and WHO tumor grade was independently associated with ¹⁸ F-FDG accumulation. Only 25% of functional tumors (4/16) and 8% of insulinomas (1/12) were ¹⁸ F-FDG-positive. In a Kaplan-Meier analysis in patients with non-functioning tumors (n = 56), ¹⁸ F-FDG-positivity was significantly correlated with poorer recurrence-free survival (RFS) but had no correlation with overall survival. In univariate analysis of factors associated with shorter RFS, male gender, prevalence of nodal metastasis, WHO tumor grade ≥G2, or ¹⁸ F-FDG-positive disease were significantly higher in patients with shorter RFS, whereas only ¹⁸ F-FDG-positivity was associated with shorter RFS in multivariate analyses.

CONCLUSIONS

The avidity of ¹⁸ F-FDG-PET/CT was associated with metastatic behavior of pancreatic neuroendocrine tumors and recurrence after treatment of non-functioning tumors.

Risk factors for short recurrence-free survival after resection of pancreatic neuroendocrine tumor (PanNET) liver metastases: which patients should undergo resection?

Background: In the treatment of metastatic pancreatic neuroendocrine tumors (PanNETs), surgical resection is the first choice if curative resection is expected. However, most patients develop recurrence after resection of liver metastasis. Because one of the benefits of resection is to gain a tumor-free period for the patients, it is important to identify which patients achieve longer recurrence-free survival (RFS) by resection. In this study, the clinicopathological factors associated with RFS after resection of metastatic PanNETs in the liver were evaluated to identify the patient group that is suitable for resection.Methods: Consecutively diagnosed patients with PanNET liver metastasis with resection at our hospital from January 2000 to July 2019 were evaluated. A total of 26 metastatic PanNET patients with primary liver resections were evaluated. The median follow-up time was 48.3 months.Results: There were 18 NET recurrences of the total 26 resections, with a median RFS of 17.9 months. Independent risk factors for short RFS were a high Ki67 index (p = .009) and the number of resected tumors (p = .045). When the cut-off value for the Ki67 index was 5.0% and that for the number of resected tumors was 6, Ki67 > 5.0% tumors had shorter RFS (4.9 months vs. 38.2 months p = .006), and patients with tumors > = 7 tumors had shorter RFS (4.7 months vs. 27.5 months p = .001).Conclusions: These findings indicate that good candidates for resection of metastatic tumors of PanNETs could be patients with low Ki67 tumors and a small number of metastatic tumors.

Familial Pancreatic Cancer and Surveillance of High-Risk Individuals

Family history of pancreatic cancer (PC) is a risk factor for PC development, and the risk level correlates with the number of affected families. A case of PC with ≥1 PC cases in the first-degree relative is broadly defined as familial pancreatic cancer (FPC) and accounts for 5% to 10% of total PC cases. FPC possesses several epidemiological, genetic and clinicopathological aspects that are distinct from those of conventional PCs. In Western countries, FPC registries have been established since the 1990s, and high-risk individuals are screened to detect early PCs. For the pharmacotherapy of FPC, especially in cases with germline pathogenic BRCA mutations, regimens using platinum and poly (ADP-ribose) polymerase inhibitor have recently been studied for their effectiveness. To date, the concept of FPC has prevailed in Western countries, and it has begun to infiltrate into Eastern countries. As the genetic background and environmental conditions vary in association with ethnicity and living area, we need to establish our own FPC registries and accumulate data in Asian countries.

Combination of postoperative C-reactive protein value and computed tomography imaging can predict severe pancreatic fistula after pancreatoduodenectomy

BACKGROUND

Recent management after pancreatoduodenectomy recommends either omission of prophylactic drainage or early removal. This potentially makes the diagnosis of postoperative pancreatic fistula (POPF) difficult because the diagnosis is based on the amylase value of drain effluent. The aim of this study was to determine if severe POPF could be predicted independent of drainage information.

METHODS

Records of consecutive patients who underwent pancreatoduodenectomy between 2012 and 2018 were included for further analysis. The presence of a peripancreatic collection (PC) on routine postoperative (day7) computed tomography (early CT) and perioperative characteristics were analyzed.

RESULTS

PC appeared in 82/211 patients (39%) and was associated with clinically relevant POPF (p < 0.001). The C-reactive protein (CRP) on postoperative day5 was a good predictor of severe POPF (needing interventional therapy or Grade C) (area under the receiver operating characteristics curve, 0.802; 95% confidence interval, 0.702-0.875). Presence of a PC and a high CRP value were independent risk factors for severe POPF following multivariate analysis. The combination of CRP<5.0 mg/dL on postoperative day 5 and the absence of a PC had 98% negative predictive value.

CONCLUSION

The combination of CRP measurement and PC evaluation by early CT was useful in predicting severe POPF after pancreatoduodenectomy.

A multicenter prospective registration study on laparoscopic pancreatectomy in Japan: report on the assessment of 1,429 patients

BACKGROUND

Prospective studies are needed to understand the safety and feasibility of laparoscopic pancreatectomy. The aim of the present study was to describe laparoscopic pancreatectomy currently undertaken in Japan, using a prospective registration system.

METHODS

Patient characteristics and planned operations were registered preoperatively, and then the performed operation and outcomes were reported using an online system. Collected data were also compared between institutions based on their level of experience. This study was registered with UMIN000022836.

RESULTS

Available data were obtained from 1,429 patients at 100 Japanese institutions, including 1,197 laparoscopic distal pancreatectomies (LDPs) and 232 laparoscopic pancreatoduodenectomies (LPDs). The rates of completion for planned operations were 92% for LDP and 91% for LPD. Postoperative complication rates after LDP and LPD were 17% and 30%, and 90-day mortality rates were 0.3% and 0.4%, respectively. Shorter operation time, less blood loss, and lower incidence of pancreatic fistula were observed in institutions experienced in LDP. A higher rate of pure laparoscopic procedure and shorter operation time were noted in institutions experienced with LPD.

CONCLUSION

LDPs and LPDs are performed safely in Japan, especially in experienced institutions. Our data could support the next challenges in the field of laparoscopic pancreatectomy.

International consensus statement on robotic pancreatic surgery

The robotic surgical system has been applied to various types of pancreatic surgery. However, controversies exist regarding a variety of factors including the safety, feasibility, efficacy, and cost-effectiveness of robotic surgery. This study aimed to evaluate the current status of robotic pancreatic surgery and put forth experts' consensus and recommendations to promote its development. Based on the WHO Handbook for Guideline Development, a Consensus Steering Group* and a Consensus Development Group were established to determine the topics, prepare evidence-based documents, and generate recommendations. The GRADE Grid method and Delphi vote were used to formulate the recommendations. A total of 19 topics were analyzed. The first 16 recommendations were generated by GRADE using an evidence-based method (EBM) and focused on the safety, feasibility, indication, techniques, certification of the robotic surgeon, and cost-effectiveness of robotic pancreatic surgery. The remaining three recommendations were based on literature review and expert panel opinion due to insufficient EBM results. Since the current amount of evidence was low/meager as evaluated by the GRADE method, further randomized controlled trials (RCTs) are needed in the future to validate these recommendations.

Association Between Preanalytical Factors and Tumor Mutational Burden Estimated by Next-Generation Sequencing-Based Multiplex Gene Panel Assay

BACKGROUND

Tumor mutational burden (TMB) measured via next-generation sequencing (NGS)-based gene panel is a promising biomarker for response to immune checkpoint inhibitors (ICIs) in solid tumors. However, little is known about the preanalytical factors that can affect the TMB score.

MATERIALS AND METHODS

Data of 199 patients with solid tumors who underwent multiplex NGS gene panel (OncoPrime), which was commercially provided by a Clinical Laboratory Improvement Amendments-licensed laboratory and covered 0.78 megabase (Mb) of capture size relevant to the TMB calculation, were reviewed. Associations between the TMB score and preanalytical factors, including sample DNA quality, sample type, sampling site, and storage period, were analyzed. Clinical outcomes of patients with a high TMB score (≥10 mutations per megabase) who received anti-programmed cell death protein 1 antibodies (n = 22) were also analyzed.

RESULTS

Low DNA library concentration (<5 nM), formalin-fixed paraffin-embedded tissue (FFPE), and the prolonged sample storage period (range, 0.9-58.1 months) correlated with a higher TMB score. After excluding low DNA library samples from the analysis, FFPE samples, but not the sample storage period, exhibited a marked correlation with a high TMB score. Of 22 patients with a high TMB score, we observed the partial response in 2 patients (9.1%).

CONCLUSION

Our results indicate that the TMB score estimated via NGS-based gene panel could be affected by the DNA library concentration and sample type. These factors could potentially increase the false-positive and/or artifactual variant calls. As each gene panel has its own pipeline for variant calling, it is unknown whether these factors have a significant effect in other platforms.

IMPLICATIONS FOR PRACTICE

A high tumor mutational burden score, as estimated via next-generation sequencing-based gene panel testing, should be carefully interpreted as it could be affected by the DNA library concentration and sample type.

Nardilysin inhibits pancreatitis and suppresses pancreatic ductal adenocarcinoma initiation in mice

OBJECTIVE

Nardilysin (NRDC), a zinc peptidase, exhibits multiple localisation-dependent functions including as an enhancer of ectodomain shedding in the extracellular space and a transcriptional coregulator in the nucleus. In this study, we investigated its functional role in exocrine pancreatic development, homeostasis and the formation of pancreatic ductal adenocarcinoma (PDA).

DESIGN

We analysed Ptf1a-Cre; Nrdc^flox/flox mice to investigate the impact of Nrdc deletion. Pancreatic acinar cells were isolated from Nrdc^flox/flox mice and infected with adenovirus expressing Cre recombinase to examine the impact of Nrdc inactivation. Global gene expression in Nrdc-cKO pancreas was analysed compared with wild-type pancreas by microarray analysis. We also analysed Ptf1a-Cre; Kras^G12D; Nrdc^flox/flox mice to investigate the impact of Nrdc deletion in the context of oncogenic Kras. A total of 51 human samples of pancreatic intraepithelial lesions (PanIN) and PDA were examined by immunohistochemistry for NRDC.

RESULTS

We found that pancreatic deletion of Nrdc leads to spontaneous chronic pancreatitis concomitant with acinar-to-ductal conversion, increased apoptosis and atrophic pancreas in mice. Acinar-to-ductal conversion was observed mainly through a non-cell autonomous mechanism, and the expression of several chemokines was significantly increased in Nrdc-null pancreatic acinar cells. Furthermore, pancreatic deletion of Nrdc dramatically accelerated Kras^G12D -driven PanIN and subsequent PDA formation in mice. These data demonstrate a previously unappreciated anti-inflammatory and tumour suppressive functions of Nrdc in the pancreas in mice. Finally, absence of NRDC expression was observed in a subset of human PanIN and PDA.

CONCLUSION

Nrdc inhibits pancreatitis and suppresses PDA initiation in mice.

Clinical and experimental studies of intraperitoneal lipolysis and the development of clinically relevant pancreatic fistula after pancreatic surgery

Background

Visceral obesity is one of the risk factors for clinically relevant pancreatic fistula after pancreatic resection. The objective of this study was to evaluate the impact of intraperitoneal lipolysis on postoperative pancreatic fistula.

Methods

The degree of intraperitoneal lipolysis was investigated by measuring the free fatty acid concentration in drain discharge in patients after pancreatic resection. An experimental pancreatic fistula model was prepared by pancreatic transection, and the impact of intraperitoneal lipolysis was evaluated by intraperitoneal administration of triolein (triglyceride) with, or without orlistat (lipase inhibitor).

Results

Thirty-three patients were included in the analysis. The free fatty acid concentration in drain discharge on postoperative day 1 was significantly associated with the development of a clinically relevant pancreatic fistula (P = 0·004). A higher free fatty acid concentration in drain discharge was associated with more visceral adipose tissue (P = 0·009). In the experimental model that included 98 rats, intraperitoneal lipolysis caused an increased amount of pancreatic juice leakage and multiple organ dysfunction. Intraperitoneal administration of a lipase inhibitor reduced lipolysis and prevented deterioration of the fistula.

Conclusion

Intraperitoneal lipolysis significantly exacerbates pancreatic fistula after pancreatic resection. Inhibition of lipolysis by intraperitoneal administration of a lipase inhibitor could be a promising therapy to reduce clinically relevant postoperative pancreatic fistula.

Henoch-Schönlein Purpura After Living Donor Liver Transplantation: Report of the First Case

Henoch-Schönlein purpura (HSP) is a systemic vasculitis affecting the small vessels that mainly presents in children and young adults. It is characterized by tissue deposition of immunoglobulin A (IgA) immune complexes with the classic manifestations of purpura, arthritis, arthralgia, and gastrointestinal and renal involvements. We report a case of HSP nephritis that occurred 2 years after living-donor liver transplantation (LDLT). After pulse steroid administration, the patient's symptoms disappeared and blood markers normalized. To the best of our knowledge, this is the first HSP case to be reported in a liver transplant recipient.

Difficulty scoring system in laparoscopic distal pancreatectomy

BACKGROUND

Several factors affect the level of difficulty of laparoscopic distal pancreatectomy (LDP). The purpose of this study was to develop a difficulty scoring (DS) system to quantify the degree of difficulty in LDP.

METHODS

We collected clinical data for 80 patients who underwent LDP. A 10-level difficulty index was developed and subcategorized into a three-level difficulty index; 1-3 as low, 4-6 as intermediate, and 7-10 as high index. The automatic linear modeling (LINEAR) statistical tool was used to identify factors that significantly increase level of difficulty in LDP.

RESULTS

The operator's 10-level DS concordance between the 10-level DS by the reviewers, LINEAR index DS, and clinical index DS systems were analyzed, and the weighted Cohen's kappa statistic were at 0.869, 0.729, and 0.648, respectively, showing good to excellent inter-rater agreement. We identified five factors significantly affecting level of difficulty in LDP; type of operation, resection line, proximity of tumor to major vessel, tumor extension to peripancreatic tissue, and left-sided portal hypertension/splenomegaly.

CONCLUSIONS

This novel DS for LDP adequately quantified the degree of difficulty, and can be useful for selecting patients for LDP, in conjunction with fitness for surgery and prognosis.

The BRG1/SOX9 axis is critical for acinar cell-derived pancreatic tumorigenesis

Chromatin remodeler Brahma related gene 1 (BRG1) is silenced in approximately 10% of human pancreatic ductal adenocarcinomas (PDAs). We previously showed that BRG1 inhibits the formation of intraductal pancreatic mucinous neoplasm (IPMN) and that IPMN-derived PDA originated from ductal cells. However, the role of BRG1 in pancreatic intraepithelial neoplasia-derived (PanIN-derived) PDA that originated from acinar cells remains elusive. Here, we found that exclusive elimination of Brg1 in acinar cells of Ptf1a-CreER; KrasG12D; Brg1fl/fl mice impaired the formation of acinar-to-ductal metaplasia (ADM) and PanIN independently of p53 mutation, while PDA formation was inhibited in the presence of p53 mutation. BRG1 bound to regions of the Sox9 promoter to regulate its expression and was critical for recruitment of upstream regulators, including PDX1, to the Sox9 promoter and enhancer in acinar cells. SOX9 expression was downregulated in BRG1-depleted ADMs/PanINs. Notably, Sox9 overexpression canceled this PanIN-attenuated phenotype in KBC mice. Furthermore, Brg1 deletion in established PanIN by using a dual recombinase system resulted in regression of the lesions in mice. Finally, BRG1 expression correlated with SOX9 expression in human PDAs. In summary, BRG1 is critical for PanIN initiation and progression through positive regulation of SOX9. Thus, the BRG1/SOX9 axis is a potential target for PanIN-derived PDA.

Nutritional support and therapy in pancreatic surgery: A position paper of the International Study Group on Pancreatic Surgery (ISGPS)

BACKGROUND

The optimal nutritional therapy in the field of pancreatic surgery is still debated.

METHODS

An international panel of recognized pancreatic surgeons and pancreatologists decided that the topic of nutritional support was of importance in pancreatic surgery. Thus, they reviewed the best contemporary literature and worked to develop a position paper to provide evidence supporting the integration of appropriate nutritional support into the overall management of patients undergoing pancreatic resection. Strength of recommendation and quality of evidence were based on the approach of the grading of recommendations assessment, development and evaluation Working Group.

RESULTS

The measurement of nutritional status should be part of routine preoperative assessment because malnutrition is a recognized risk factor for surgery-related complications. In addition to patient's weight loss and body mass index, measurement of sarcopenia and sarcopenic obesity should be considered in the preoperative evaluation because they are strong predictors of poor short-term and long-term outcomes. The available data do not show any definitive nutritional advantages for one specific type of gastrointestinal reconstruction technique after pancreatoduodenectomy over the others. Postoperative early resumption of oral intake is safe and should be encouraged within enhanced recovery protocols, but in the case of severe postoperative complications or poor tolerance of oral food after the operation, supplementary artificial nutrition should be started at once. At present, there is not enough evidence to show the benefit of avoiding oral intake in clinically stable patients who are complicated by a clinically irrelevant postoperative pancreatic fistula (a so-called biochemical leak), while special caution should be given to feeding patients with clinically relevant postoperative pancreatic fistula orally. When an artificial nutritional support is needed, enteral nutrition is preferred whenever possible over parenteral nutrition. After the operation, regardless of the type of pancreatic resection or technique of reconstruction, patients should be monitored carefully to assess for the presence of endocrine and exocrine pancreatic insufficiency. Although fecal elastase-1 is the most readily available clinical test for detection of pancreatic exocrine insufficiency, its sensitivity and specificity are low. Pancreatic enzyme replacement therapy should be initiated routinely after pancreatoduodenectomy and in patients with locally advanced disease and continued for at least 6 months after surgery, because untreated pancreatic exocrine insufficiency may result in severe nutritional derangement.

CONCLUSION

The importance of this position paper is the consensus reached on the topic. Concentrating on nutritional support and therapy is of utmost value in pancreatic surgery for both short- and long-term outcomes.

ARID1A Maintains Differentiation of Pancreatic Ductal Cells and Inhibits Development of Pancreatic Ductal Adenocarcinoma in Mice

BACKGROUND & AIMS

The ARID1A gene encodes a protein that is part of the large adenosine triphosphate (ATP)-dependent chromatin remodeling complex SWI/SNF and is frequently mutated in human pancreatic ductal adenocarcinomas (PDACs). We investigated the functions of ARID1A during formation of PDACs in mice.

METHODS

We performed studies with Ptf1a-Cre;Kras^G12D mice, which express activated Kras in the pancreas and develop pancreatic intraepithelial neoplasias (PanINs), as well as those with disruption of Aird1a (Ptf1a-Cre;Kras^G12D;Arid1a^f/f mice) or disruption of Brg1 (encodes a catalytic ATPase of the SWI/SNF complex) (Ptf1a-Cre;Kras^G12D; Brg1^f/fmice). Pancreatic ductal cells (PDCs) were isolated from Arid1a^f/f mice and from Arid1a^f/f;SOX9OE mice, which overexpress human SOX9 upon infection with an adenovirus-expressing Cre recombinase. Pancreatic tissues were collected from all mice and analyzed by histology and immunohistochemistry; cells were isolated and grown in 2-dimensional and 3-dimensional cultures. We performed microarray analyses to compare gene expression patterns in intraductal papillary mucinous neoplasms (IPMNs) from the different strains of mice. We obtained 58 samples of IPMNs and 44 samples of PDACs from patients who underwent pancreatectomy in Japan and analyzed them by immunohistochemistry.

RESULTS

Ptf1a-Cre;Kras^G12D mice developed PanINs, whereas Ptf1a-Cre;Kras^G12D;Arid1a^f/f mice developed IPMNs and PDACs; IPMNs originated from PDCs. ARID1A-deficient IPMNs did not express SOX9. ARID1A-deficient PDCs had reduced expression of SOX9 and dedifferentiated in culture. Overexpression of SOX9 in these cells allowed them to differentiate and prevented dilation of ducts. Among mice with pancreatic expression of activated Kras, those with disruption of Arid1a developed fewer PDACs from IPMNs than mice with disruption of Brg1. ARID1A-deficient IPMNs had reduced activity of the mTOR pathway. Human IPMN and PDAC specimens had reduced levels of ARID1A, SOX9, and phosphorylated S6 (a marker of mTOR pathway activation). Levels of ARID1A correlated with levels of SOX9 and phosphorylated S6.

CONCLUSIONS

ARID1A regulates expression of SOX9, activation of the mTOR pathway, and differentiation of PDCs. ARID1A inhibits formation of PDACs from IPMNs in mice with pancreatic expression of activated KRAS and is down-regulated in IPMN and PDAC tissues from patients.

Clinical results of dynamic tumor tracking intensity-modulated radiotherapy with real-time monitoring for pancreatic cancers using a gimbal mounted linac

Objectives

We performed dynamic tumor-tracking IMRT (DTT-IMRT) in locally advanced pancreatic cancer (LAPC) patients using a gimbaled linac of Vero4DRT. The purpose of this study is to report the first clinical results.

Methods

From June 2013 to June 2015, eleven LAPC patients enrolled in this study and DTT-IMRT was successfully performed. The locoregional progression free survival (LRPFS), distant metastasis free survival (DMFS), overall survival (OS), hematologic and gastrointestinal (GI) toxicities were evaluated. Oncologic outcomes were estimated using Kaplan-Meier analysis, and toxicities using CTCAE v4.0.

Results

The median radiation dose was 48 Gy (range, 45-51) in 15 fractions. Concurrent chemoradiotherapy (CCRT) was performed using gemcitabine in 9 patients and S-1 in one, while one patient refused. With a median follow-up of 22.9 months, 1-year LRPFS, DMFS, and OS rates were 90.9%, 70.7%, and 100%, respectively. Median survival time was 23.6 months. Grade-3 leucopenia and neutropenia were observed in two (18%) and one patient (9%), respectively. Grade-2 acute GI toxicity occurred in 2 patients (18%) and late grade-3 in 1 patient (9%).

Conclusions

Preliminarily application of DTT-IMRT using a gimbaled linac on CCRT in LAPC patients resulted in excellent locoregional control and OS without severe toxicity.

Association between homologous recombination repair gene mutations and response to oxaliplatin in pancreatic cancer

Objectives

We aimed to examine the association between homologous recombination repair (HRR)-related gene mutations and efficacy of oxaliplatin-based chemotherapy in patients with pancreatic ductal adenocarcinoma (PDAC).

Results

Non-synonymous mutations in HRR-related genes were found in 13 patients and only one patient had a family history of pancreatic cancer. Eight patients with HRR-related gene mutations (group A) and nine without HRR-related gene mutations (group B) received oxaliplatin-based chemotherapy. Median progression-free survival after initiation of oxaliplatin-based chemotherapy was significantly longer in group A than in group B (20.8 months vs 1.7 months, p = 0.049). Interestingly, two patients with inactivating HRR-related gene mutations who received FOLFIRINOX as first-line treatment showed exceptional responses with respect to progression-free survival for > 24 months.

Materials and Methods

Complete coding exons of 12 HRR-related genes (ATM, ATR, BAP1, BRCA1, BRCA2, BLM, CHEK1, CHEK2, FANCA, MRE11A, PALB2, and RAD51) were sequenced using a Clinical Laboratory Improvement Amendment-certified multiplex next-generation sequencing assay. Thirty consecutive PDAC patients who underwent this assay between April 2015 and July 2017 were included.

Conclusions

Our results suggest that inactivating HRR-related gene mutations are predictive of response to oxaliplatin-based chemotherapy in patients with PDAC.

International Summit on Laparoscopic Pancreatic Resection (ISLPR) "Coimbatore Summit Statements"

The International Summit on Laparoscopic Pancreatic Resection (ISLPR) was held in Coimbatore, India, on 7th and 8th of October 2016 and thirty international experts who regularly perform laparoscopic pancreatic resections participated in ISPLR from four continents, i.e., South and North America, Europe and Asia. Prior to ISLPR, the first conversation among the experts was made online on August 26th, 2016 and the structures of ISPLR were developed. The aims of ISPLR were; i) to identify indications and optimal case selection criteria for minimally invasive pancreatic resection (MIPR) in the setting of both benign and malignant diseases; ii) standardization of techniques to increase the safety of MIPR; iii) identification of common problems faced during MIPR and developing associated management strategies; iv) development of clinical protocols to allow early identification of complications and develop the accompanying management plan to minimize morbidity and mortality. As a process for interactive discussion, the experts were requested to complete an online questionnaire consisting of 65 questions about the various technical aspects of laparoscopic pancreatic resections. Two further web-based meetings were conducted prior to ISPLR. Through further discussion during ISPLR, we have created productive statements regarding the topics of Disease, Implementation, Patients, Techniques, and Instrumentations (DIPTI) and hereby publish them as "Coimbatore Summit Statements".

A Prospective Study of Intensity-modified Radiation Therapy in Comparison with Conventional 3D-RT for BR Pancreatic Cancer Patients with Arterial Involvement

BACKGROUND/AIM

Intensity-modulated radiation therapy (IMRT) is a form of radiation therapy that allows accurate irradiation with reduced damage to surrounding tissues. Here, we analyzed borderline-resectable pancreatic cancer (BRPC) with arterial abutment (BR-A) patients with IMRT as neoadjuvant therapy and performed comparisons with patients with conventional RT to clarify the advantages of IMRT as a neoadjuvant therapy.

PATIENTS AND METHODS

Thirty BR-A patients treated at our hospital between January 2012 and December 2015 were divided into two groups: 12 patients underwent conventional 3D-RT before resection (RT group); and 18 patients underwent IMRT before resection (IMRT group). We analyzed safety, tumor resection rate, histological classification of the tumor and overall survival.

RESULTS

The R0 rate was 84% for the IMRT group and 83% for the RT group. Local therapeutic effects as assessed by Evans classification showed a higher local control rate in the IMRT group (Grade: 1, 0%; 2a, 25%; 2b, 41.6%; 3, 17%; 4, 8%) than in the RT group (Grade: 1, 17%; 2a, 50%; 2b, 17%; 3, 17%; 4, 0%). The cumulative dose of S1 treatment as adjuvant therapy was much smaller in the RT group (18.3%) compared to that in the IMRT group (57.1%, p=0.047), and with better subsequent overall survival rate (MST 32 months vs. 13.8 months, p=0.0273).

CONCLUSION

The IMRT group showed a better control rate than the RT group. The neoadjuvant IMRT has advantages of higher completion rate of adjuvant chemotherapy with better nutritional status and better subsequent overall survival rate (OS).

Comparison of Recurrence Between Pancreatic and Duodenal Neuroendocrine Neoplasms After Curative Resection: A Single-Institution Analysis

BACKGROUND

The primary site of a neuroendocrine neoplasms (NEN) around the head of the pancreas is sometimes difficult to assess before resection, and the characteristics of the primary site around this region have not been elucidated for recurrence after curative resection. In this study, the clinicopathologic characteristics of pancreatic NEN (PanNEN) and duodenal NEN (DuNEN) were evaluated, and the risk factors as well as the recurrence types after resection were investigated.

METHODS

Consecutively diagnosed NEN patients at the authors' hospital from January 2000 to July 2016 were evaluated in this study. For 117 PanNEN patients and 31 non-ampullary DuNEN patients, R0 resection was achieved. The median follow-up period was 8.1 years.

RESULTS

In this study, 27 PanNEN patients (23.1%) had recurrences, with a median disease-free survival (DFS) of 133 months, whereas 11 DuNEN patients (35.5%) had recurrences, with a median DFS of 156 months. The PanNEN patients tended to have primary recurrence in the liver (85.2%), followed by lymph nodes (11.1%). The independent risk factors for short DFS were lymph node metastasis at resection (p = 0.001) and microvascular invasion (p = 0.048). In contrast, the DuNEN patients were likely to have lymph node metastasis (81.8%). The independent risk factors for short DFS were lymph node metastasis at resection (p = 0.003) and large diameter (p = 0.013).

CONCLUSIONS

Most initial recurrences of PanNEN occurred in the liver, whereas those of DuNEN appeared in lymph nodes, suggesting that proper diagnosis of the primary site and appropriate imaging methods for surveillance after resection are necessary.

Successful laparoscopic distal pancreatectomy for a large solid pseudopapillary neoplasm: A case report

A 30-year-old Japanese woman presented at our hospital with a pancreatic tumor. Contrast-enhanced CT revealed a tumor with a 12-cm diameter in the pancreatic body and tail. In the preoperative setting, endoscopic ultrasound-guided fine-needle aspiration permitted a histopathological diagnosis of solid pseudopapillary neoplasm. Twhe patient underwent laparoscopic distal pancreatectomy with splenectomy. Our procedure involved three steps. Firstly, the splenic artery was occluded to block inflow of blood to the tumor. Then, we transected the neck of the pancreas using radical antegrade modular pancreatosplenectomy. Finally, hand-assisted laparoscopic surgery allowed us to secure the operating field and easily handle the large tumor. This enabled us to accomplish laparoscopic distal pancreatectomy, and en-bloc resection was completed. The patient was discharged without major complications. Laparoscopic distal pancreatectomy for huge solid pancreatic tumors can be completed safely.

A case of successful conversion from everolimus to surgical resection of a giant pancreatic neuroendocrine tumor

Background

Although pancreatic neuroendocrine tumors generally have a far better prognosis relative to pancreatic cancer, the varied manifestations lead to treatment-related challenges. Everolimus therapy is generally recommended for patients with advanced pancreatic neuroendocrine tumors; however, its efficacy in a neoadjuvant setting remains unclear. Here we present a case of a giant pancreatic neuroendocrine tumor with a portal tumor thrombus that became resectable after everolimus therapy.

Case presentation

A 62-year-old woman was admitted to our hospital for surgical resection of a giant pancreatic neuroendocrine tumor in the left upper abdomen. Unfortunately, she was ineligible for surgery because the tumor had extended near the hepatic hilus in the portal vein, and she was administered everolimus (10 mg/day). After 2 years of this therapy, the extent of portal vein involvement had decreased, despite the lack of significant changes in the tumor size, and the hepatic hilus became free of disease. She was subsequently referred to us for resection via distal pancreatectomy with portal vein reconstruction because the tumor had begun to grow slowly. Pathological review identified a grade 2 neuroendocrine tumor with no lymph node metastasis. The patient’s postoperative course was uneventful, and she has remained recurrence-free for 27 months, despite a lack of additional treatment.

Conclusions

Our experience suggests that everolimus could be useful for neoadjuvant therapy in cases of locally advanced pancreatic neuroendocrine tumor.

Abstract 3518: Brg1 plays a critical role in PanIN formation through regulating Sox9 expression

Background: Mutations of SWI/SNF chromatin remodeling complexes are one of the hallmarks of human pancreatic ductal adenocarcinoma (PDA). Brahma related gene 1 (Brg1) is a catalytic ATPase subunit of SWI/SNF complexes and Brg1 is silenced in about 10% of human PDA. Recent study revealed that Brg1 inhibits formation of intraductal pancreatic mucinous neoplasm (IPMN) and IPMN-derived PDA in the context of oncogenic Kras and that IPMNs originate from adult pancreatic ductal cells, demonstrating a tumor suppressive role of Brg1. However, the role of Brg1 in the formation of pancreatic intraepithelial neoplasia (PanIN) from acinar cells and PanIN-derived PDA is not fully understood.

Aim: To investigate the functional role of Brg1 in the formation of PanIN

Methods and Results: We generated Ptf1a-CreER; KrasG12D; Brg1f/f (KBC) mice, in which Brg1 is deleted exclusively in adult pancreatic acinar cells along with expression of oncogenic Kras upon tamoxifen induction of Cre activity and assessed spontaneous acinar-to-ductal metaplasia (ADM) and PanIN formation. We found that ADM and PanIN formation was significantly decreased in KBC mice compared with littermate controls. Next, we induced caerulein-acute pancreatitis to KBC mice and assessed for pancreatitis-induced tumorigenesis. We found that PanINs were decreased in KBC mice compared with littermate controls, although pancreatitis-induced ADMs were widely observed in KBC mice. Since Brg1 is known to critical regulator of p53, mutant p53 allele was crossed with KBC mice. Unexpectedly, even in the context of mutant p53, loss of Brg1 significantly deceased PanIN formation. These results suggest that Brg1 plays a tumor-supportive role in acinar cell-derived PanIN formation in various contexts. Primary acinar cell culture experiments revealed that ADM formation was markedly reduced in the absence of Brg1 and that Sox9 expression was downregulated in Brg1-depleted acinar cells. Furthermore, we confirmed that Sox9 expression is downregulated in Brg1-depleted ADMs/PanINs compared with Brg1-retained ADMs/PanINs by immunohistochemistry. To determine the functional relationship between Brg1 and Sox9, we generated Ptf1a-CreER; KrasG12D; Brg1f/f; Sox9OE mice, in which Sox9 is constitutively overexpressed. Remarkably, Sox9 overexpression canceled the phenotype of decrease in PanIN formation by Brg1 deletion. Furthermore, to investigate whether Brg1/Sox9 axis is observed in human PanIN-derived PDAs, we performed immunohistochemistry of Brg1 and Sox9 in human PanIN-derived PDAs. In 27 human PDAs, all of 5 PDAs with low Brg1 expression had low Sox9 expression.

Conclusions: Our results suggest that Brg1 plays a critical role in acinar cell-derived PanIN formation in part through regulating Sox9 expression positively. Our data underscore a cell-type specific, context-dependent role of Brg1 in the initiation of PDA formation.

Citation Format: Motoyuki Tsuda, Akihisa Fukuda, Satoshi Ogawa, Kenji Masuo, Norihiro Goto, Yukiko Hiramatsu, Yu Muta, Kozo Ikuta, Yoshito Kimura, Yoshihide Matsumoto, Yutaka Takada, Takuto Yoshioka, Takahisa Maruno, Haruhiko Akiyama, Kyoichi Takaori, Shinji Uemoto, Tsutomu Chiba, Hiroshi Seno. Brg1 plays a critical role in PanIN formation through regulating Sox9 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3518. doi:10.1158/1538-7445.AM2017-3518

Clinical sequencing using a next-generation sequencing-based multiplex gene assay in patients with advanced solid tumors

Advances in next‐generation sequencing (NGS) technologies have enabled physicians to test for genomic alterations in multiple cancer‐related genes at once in daily clinical practice. In April 2015, we introduced clinical sequencing using an NGS‐based multiplex gene assay (OncoPrime) certified by the Clinical Laboratory Improvement Amendment. This assay covers the entire coding regions of 215 genes and the rearrangement of 17 frequently rearranged genes with clinical relevance in human cancers. The principal indications for the assay were cancers of unknown primary site, rare tumors, and any solid tumors that were refractory to standard chemotherapy. A total of 85 patients underwent testing with multiplex gene assay between April 2015 and July 2016. The most common solid tumor types tested were pancreatic (n = 19; 22.4%), followed by biliary tract (n = 14; 16.5%), and tumors of unknown primary site (n = 13; 15.3%). Samples from 80 patients (94.1%) were successfully sequenced. The median turnaround time was 40 days (range, 18–70 days). Potentially actionable mutations were identified in 69 of 80 patients (86.3%) and were most commonly found in TP53 (46.3%), KRAS (23.8%), APC (18.8%), STK11 (7.5%), and ATR (7.5%). Nine patients (13.0%) received a subsequent therapy based on the NGS assay results. Implementation of clinical sequencing using an NGS‐based multiplex gene assay was feasible in the clinical setting and identified potentially actionable mutations in more than 80% of patients. Current challenges are to incorporate this genomic information into better therapeutic decision making.

Abdominal contamination with Candida albicans after pancreaticoduodenectomy is related to hemorrhage associated with pancreatic fistulas

BACKGROUND/OBJECTIVES

Pancreatic fistulas are one of the most frequent morbidities after pancreaticoduodenectomy. Several reports have suggested a relationship between bacterial infections and postoperative pancreatic fistulas, although details of the mechanisms involved in hemorrhage in association with the fistulas have not been elucidated. This study retrospectively examined the relationship between positive drainage culture and hemorrhage associated with pancreatic fistulas after pancreaticoduodenectomy.

METHODS

From January 2012 to December 2015, 142 consecutive patients underwent pancreaticoduodenectomy at our institution. We retrospectively reviewed the patients' demographic data, perioperative laboratory data, and drainage culture results.

RESULTS

Twenty-four (17%) patients had clinically relevant postoperative pancreatic fistulas, whereas thirty-four (24%) patients experienced positive drainage culture. Multivariable analysis revealed that positive drainage culture was independently associated with clinically relevant postoperative pancreatic fistulas (odds ratio, 18.1; 95% confidence interval, 5.5-72.2; P < 0.001). Additionally, the prevalence of Candida albicans in the lavage of eight patients significantly correlated with hemorrhage associated with pancreatic fistulas (odds ratio, 43.5; 95% confidence interval, 6.2-513.3; P < 0.001). Seventy-five percent (6/8) of these patients suffered potentially lethal hemorrhagic complications and needed intervention.

CONCLUSIONS

A positive abdominal drainage culture is associated with the development of pancreatic fistulas. Moreover, the presence of Candida albicans in drainage fluid may be a risk factor for hemorrhagic complications.

The 2016 update of the International Study Group (ISGPS) definition and grading of postoperative pancreatic fistula: 11 Years After

BACKGROUND

In 2005, the International Study Group of Pancreatic Fistula developed a definition and grading of postoperative pancreatic fistula that has been accepted universally. Eleven years later, because postoperative pancreatic fistula remains one of the most relevant and harmful complications of pancreatic operation, the International Study Group of Pancreatic Fistula classification has become the gold standard in defining postoperative pancreatic fistula in clinical practice. The aim of the present report is to verify the value of the International Study Group of Pancreatic Fistula definition and grading of postoperative pancreatic fistula and to update the International Study Group of Pancreatic Fistula classification in light of recent evidence that has emerged, as well as to address the lingering controversies about the original definition and grading of postoperative pancreatic fistula.

METHODS

The International Study Group of Pancreatic Fistula reconvened as the International Study Group in Pancreatic Surgery in order to perform a review of the recent literature and consequently to update and revise the grading system of postoperative pancreatic fistula.

RESULTS

Based on the literature since 2005 investigating the validity and clinical use of the original International Study Group of Pancreatic Fistula classification, a clinically relevant postoperative pancreatic fistula is now redefined as a drain output of any measurable volume of fluid with an amylase level >3 times the upper limit of institutional normal serum amylase activity, associated with a clinically relevant development/condition related directly to the postoperative pancreatic fistula. Consequently, the former "grade A postoperative pancreatic fistula" is now redefined and called a "biochemical leak," because it has no clinical importance and is no longer referred to a true pancreatic fistula. Postoperative pancreatic fistula grades B and C are confirmed but defined more strictly. In particular, grade B requires a change in the postoperative management; drains are either left in place >3 weeks or repositioned through endoscopic or percutaneous procedures. Grade C postoperative pancreatic fistula refers to those postoperative pancreatic fistula that require reoperation or lead to single or multiple organ failure and/or mortality attributable to the pancreatic fistula.

CONCLUSION

This new definition and grading system of postoperative pancreatic fistula should lead to a more universally consistent evaluation of operative outcomes after pancreatic operation and will allow for a better comparison of techniques used to mitigate the rate and clinical impact of a pancreatic fistula. Use of this updated classification will also allow for more precise comparisons of surgical quality between surgeons and units who perform pancreatic surgery.