Factors affecting nonfunctioning small pancreatic neuroendocrine neoplasms and proposed new treatment strategies

BACKGROUND & AIMS

Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs.

METHODS

In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the WHO 2019 classification. Overall, 1,490 patients met the eligibility criteria, and 1,014 were included in the analysis cohort.

RESULTS

In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs. G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate.

CONCLUSIONS

NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

Preoperative Endoscopic Minor Papilla Sphincterotomy for Pancreas Divisum in a Patient with Pancreatic Cancer Who Underwent Laparoscopic Distal Pancreatectomy

BACKGROUND

Pancreas divisum (PD) is a congenital anomaly that occurs due to failure of fusion of the dorsal and ventral pancreatic ductal systems.1-3 In PD, pancreatic juice drains mainly through the minor papilla via the dorsal duct, leading to high intraductal pressure, which can cause pancreatitis.1-3 We report a case of PD that underwent preoperative decompression using endoscopic minor papilla sphincterotomy (EMPS) before laparoscopic distal pancreatectomy (LDP) for pancreatic cancer.3 METHODS: The patient was a 74-year-old woman with pancreatic tail cancer, measuring 35 mm in size, in PD with an entirely dilated dorsal duct, implying high, intraductal pressure caused by minor papillary dysfunction. We performed EMPS to prevent postoperative pancreatitis and pancreatic fistula before LDP using a left-posterior approach, as previously described.4 As the pancreatic transection margin was positive for high-grade pancreatic intraepithelial neoplasia on intraoperative pathology, an additional resection of the pancreatic head to the right side of the portal vein was performed after the liberation of the gastroduodenal artery with both the dorsal and ventral pancreatic ducts ligated and divided.

RESULTS

The operative time was 421 min, and blood loss was 70 mL. The postoperative course was uneventful, with no evidence of pancreatitis or pancreatic fistula. The patient was discharged on postoperative Day 10. Postoperative computed tomography revealed reduced dilatation of the dorsal duct.

CONCLUSIONS

Preoperative EMPS may be effective in preventing pancreatic fistula after LDP in patients with PD.

Circularity of islets is a distinct marker for the pathological diagnosis of adult non-neoplastic hyperinsulinemic hypoglycemia using surgical specimens

BACKGROUND

Adult non-neoplastic hyperinsulinemic hypoglycemia (ANHH), also known as adult-onset nesidioblastosis, is a rare cause of endogenous hyperinsulinemic hypoglycemia in adults. This disease is characterized by diffuse hyperplasia of pancreatic endocrine cells and is diagnosed by a pathological examination. While diagnostic criteria for this disease have already been proposed, we established more quantitative criteria for evaluating islet morphology.

METHODS

We measured the number, maximum diameter, total area, and circularity (representing how closely islets resemble perfect spheres) of islets contained in representative sections of ANHH (n = 4) and control cases (n = 5) using the NIS-Elements software program. We also measured the average cell size, percentage of cells with enlarged nuclei, and percentage of cells with recognizable nucleoli for each of three representative islets. We also assessed the interobserver diagnostic concordance of ANHH between five experienced and seven less-experienced pathologists.

RESULTS

There was no significant difference in the number, maximum diameter, or total area of islets between the two groups, even after correcting for these parameters per unit area. However, the number of islets with low circularity (< 0.71) per total area of the pancreatic parenchyma was significantly larger in ANHH specimens than in controls. We also found that the percentage of cells with recognizable nucleoli was significantly higher in the ANHH group than in the controls. There were no significant differences in the average cell size or the number of cells with enlarged nuclei between the groups. The correct diagnosis rate with the blind test was 47.5% ± 6.12% for experienced pathologists and 50.0% ± 8.63% for less-experienced pathologists, with no significant differences noted.

CONCLUSIONS

Low circularity, which indicates an irregular islet shape, referred to as "irregular shape and occasional enlargement of islets" and "lobulated islet structure" in a previous report, is a useful marker for diagnosing ANHH. An increased percentage of recognizable nucleoli, corresponding to "macronucleoli in β-cells," has potential diagnostic value.

The Outcomes of Neoadjuvant Chemoradiotherapy Using Moderately Hypofractionated Intensity Modulated Radiotherapy for Borderline Resectable Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

Complete resection of borderline resectable pancreatic cancer (BRPC) is difficult because of its invasion to the vital vessels. Although neoadjuvant therapy is recommended for BRPC, its optimal regimens remain unclear. Neoadjuvant chemoradiotherapy using moderately hypofractionated intensity-modulated radiotherapy (NAC-MH-IMRT) has potentials to improve the treatment outcomes with shorter treatment periods. Therefore, we evaluated the outcomes for BRPC patients treated with NAC-MH-IMRT.

MATERIALS/METHODS

Between February 2013 and June 2021, patients with BRPC treated with NAC-MH-IMRT at our institution were evaluated. All patients were classified as BRPC-A and BRPC-V according to NCCN guidelines. Information regarding patient status, tumor and treatment characteristics, margin-negative resection (R0) rates, histological effects assessed by Evans classification, and outcomes were obtained from the clinical records. Overall survival (OS) and progression-free survival (PFS) were calculated by the Kaplan-Meier method from the start date of any first treatment for BRPC. Toxicity was evaluated by CTCAE version 5.0.

RESULTS

Sixty-eight patients were included in this study (Table). All patients underwent induction chemotherapy, and 67 were treated with IMRT at 42 Gy in 15 fractions with concurrent gemcitabine (for 65) or S-1 (for 2). All patients achieved completion of radiotherapy. Fifty-seven of the 68 patients (83.8%) underwent surgical exploration, and 48 patients (70.6%) had a resection. The R0 resection was achieved in 44 patients, and the R0 resection rate was 91.7% in resected patients. Therapeutic effects by Evans classification showed as below: Grade 1/2a/2b/3/4 = 6 (12.5%)/17 (35.4%)/17 (35.4%)/7 (14.6%)/1 (2.1%). Adjuvant chemotherapy was performed for 41 patients, and S-1 and gemcitabine were used for 40 and 1 patient(s), respectively. The median follow-up time and median survival time (MST) were 23.6 months and 42.7 months, and 2-year OS and PFS were 67.3% and 30.2%, respectively. Recurrence was observed in 54 patients (79.4%), and the first recurrence pattern was as follows: 7 (13.0%)/42 (77.8%)/5 (9.3%) patients had local recurrence, distant metastases, and both of them, respectively. Regarding ≥ Grade 3 gastrointestinal toxicity related NAC-MH-IMRT, grade 3 ileus was observed in 1 patient.

CONCLUSION

NAC-MH-IMRT for BRPC showed preferable outcomes and acceptable toxicities with high completion rate.

Pancreatic RECK inactivation promotes cancer formation, epithelial-mesenchymal transition, and metastasis

RECK is downregulated in various human cancers; however, how RECK inactivation affects carcinogenesis remains unclear. We addressed this issue in a pancreatic ductal adenocarcinoma (PDAC) mouse model and found that pancreatic Reck deletion dramatically augmented the spontaneous development of PDAC with a mesenchymal phenotype, which was accompanied by increased liver metastases and decreased survival. Lineage tracing revealed that pancreatic Reck deletion induced epithelial-mesenchymal transition (EMT) in PDAC cells, giving rise to inflammatory cancer-associated fibroblast-like cells in mice. Splenic transplantation of Reck-null PDAC cells resulted in numerous liver metastases with a mesenchymal phenotype, whereas reexpression of RECK markedly reduced metastases and changed the PDAC tumor phenotype into an epithelial one. Consistently, low RECK expression correlated with low E-cadherin expression, poor differentiation, metastasis, and poor prognosis in human PDAC. RECK reexpression in the PDAC cells was found to downregulate MMP2 and MMP3, with a concomitant increase in E-cadherin and decrease in EMT-promoting transcription factors. An MMP inhibitor recapitulated the effects of RECK on the expression of E-cadherin and EMT-promoting transcription factors and invasive activity. These results establish the authenticity of RECK as a pancreatic tumor suppressor, provide insights into its underlying mechanisms, and support the idea that RECK could be an important therapeutic effector against human PDAC.

Safety and efficacy of neoadjuvant chemoradiotherapy with moderately hypofractionated intensity-modulated radiotherapy for resectable pancreatic cancer: A prospective, open-label, phase II study

BACKGROUND

Resectable pancreatic cancer (RPC) is potentially resectable on admission, and the impact of neoadjuvant therapy on these tumors is controversial. Moreover, the safety and efficacy of neoadjuvant chemoradiotherapy with moderately hypofractionated intensity-modulated radiation therapy (NACIMRT) for RPC have not been studied. Here, we conducted a phase II study to evaluate the safety and efficacy of hypofractionated NACIMRT for RPC.

METHODS

A total of 54 RPC patients were enrolled and treated according to the study protocol. We used moderately hypofractionated (45 Gy in 15 fractions) IMRT with gemcitabine to shorten the duration of radiotherapy and reduce gastrointestinal toxicity. The primary endpoint was overall survival (OS), and we subsequently analyzed the microscopically margin-negative resection (R0) rate, disease-free survival (DFS), and histologic effects and safety of NACIMRT.

RESULTS

Median OS for the cohort was 40.0 months. Forty-two patients (77.8%) underwent pancreatectomy after NACIMRT. Median DFS was 20.3 months. The R0 resection rate was 95.2% (40/42) per protocol and 85.2% (46/54) for the cohort. There were no intervention-related deaths during the study period. Local treatment response, as assessed by the CAP classification, showed no residual tumor in 4.8% of patients. Overall, 23.9% of patients experienced CTCAE grade 3 or 4 during NACIMRT. Adjuvant therapy was initiated in 88% of patients undergoing resection. Postoperative complications grade ≥3b on the Clavien-Dindo scale occurred in 4.8% of patients. CA19-9 level at enrollment was an independent prognostic factor for OS and DFS.

CONCLUSIONS

This is the first prospective study of hypofractionated IMRT as neoadjuvant therapy for RPC. Hypofractionated NACIMRT for RPC could be safely introduced with a high induction rate of adjuvant chemotherapy, with an overall survival of 40.0 months.

Pretransplant Renal Dysfunction Negatively Affects Prognosis After Living Donor Liver Transplantation: A Single-Center Retrospective Study

BACKGROUND

To evaluate the influence of preoperative renal function on prognosis after living donor liver transplantation (LDLT).

METHODS

Living donor liver transplantation cases were categorized into 3 groups as follows: renal failure with hemodialysis (HD; n = 42), renal dysfunction (RD; n = 94) (glomerular filtration rate <60 mL/min/1.73 m2), and normal renal function (NF; n = 421). The study used no prisoners, and participants were neither coerced nor paid. The manuscript complies with the Helsinki Congress and the Declaration of Istanbul.

RESULTS

Five-year overall survival (OS) rates were 59.0%, 69.3%, and 80.0% in the HD, RD, and NF groups, respectively (P < .01). The frequency of bacteremia within 90 days after LDLT was 76.2%, 37.2%, and 34.7%, respectively (P < .01 in HD vs RD and HD vs NF). Patients with bacteremia showed a worse outcome than those without (1-year OS, 65.6% vs 93.3%), thus corroborating the poor prognosis in the HD group. The high frequency of bacteremia in the HD group was mainly attributable to health care-associated bacterium, such as coagulase-negative Staphylococci, Enterococcus spp., and Pseudomonas aeruginosa. In the HD group, HD was started within 50 days before LDLT for acute renal failure in 35 patients, of which 29 (82.9%) successfully withdrew from HD after LDLT and demonstrated better prognosis (1-year OS, 69.0% vs 16.7%) than those who continued HD.

CONCLUSIONS

Preoperative renal dysfunction is associated with poor prognosis after LDLT, possibly due to a high incidence of health care-associated bacteremia.

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.

Brg1 controls stemness and metastasis of pancreatic cancer through regulating hypoxia pathway

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease. We previously reported that chromatin remodeler Brg1 is essential for acinar cell-derived PDAC formation in mice. However, the functional role of Brg1 in established PDAC and its metastasis remains unknown. Here, we investigated the importance of Brg1 for established PDAC by using a mouse model with a dual recombinase system. We discovered that Brg1 was a critical player for the cell survival and growth of spontaneously developed PDAC in mice. In addition, Brg1 was essential for metastasis of PDAC cells by inhibiting apoptosis in splenic injection and peritoneal dissemination models. Moreover, cancer stem-like property was compromised in PDAC cells by Brg1 ablation. Mechanistically, the hypoxia pathway was downregulated in Brg1-deleted mouse PDAC and BRG1-low human PDAC. Brg1 was essential for HIF-1α to bind to its target genes to augment the hypoxia pathway, which was important for PDAC cells to maintain their stem-like properties and to metastasize to the liver. Human PDAC cells with high BRG1 expression were more susceptible to BRG1 suppression. In conclusion, Brg1 plays a critical role for cell survival, stem-like property and metastasis of PDAC through the regulation of hypoxia pathway, and thus could be a novel therapeutic target for PDAC.

Controversy Over Liver Transplantation or Resection for Neuroendocrine Liver Metastasis: Tumor Biology Cuts the Deal

BACKGROUND

In patients with neuroendocrine liver metastasis (NELM), liver transplantation (LT) is an alternative to liver resection (LR), although the choice of therapy remains controversial. In this multicenter study, we aim to provide novel insight in this dispute.

METHODS

Following a systematic literature search, 15 large international centers were contacted to provide comprehensive data on their patients after LR or LT for NELM. Survival analyses were performed with the Kaplan-Meier method, while multivariable Cox regression served to identify factors influencing survival after either transplantation or resection. Inverse probability weighting and propensity score matching was used for analyses with balanced and equalized baseline characteristics.

RESULTS

Overall, 455 patients were analyzed, including 230 after LR and 225 after LT, with a median follow-up of 97 months [95% confidence interval (CI): 85-110 months]. Multivariable analysis revealed G3 grading as a negative prognostic factor for LR [hazard ratio (HR)=2.22, 95% CI: 1.04-4.77, P =0.040], while G2 grading (HR=2.52, 95% CI: 1.15-5.52, P =0.021) and LT outside Milan criteria (HR=2.40, 95% CI: 1.16-4.92, P =0.018) were negative prognostic factors in transplanted patients. Inverse probability-weighted multivariate analyses revealed a distinct survival benefit after LT. Matched patients presented a median overall survival (OS) of 197 months (95% CI: 143-not reached) and a 73% 5-year OS after LT, and 119 months (95% CI: 74-133 months) and a 52.8% 5-year OS after LR (HR=0.59, 95% CI: 0.3-0.9, P =0.022). However, the survival benefit after LT was lost if patients were transplanted outside Milan criteria.

CONCLUSIONS

This multicentric study in patients with NELM demonstrates a survival benefit of LT over LR. This benefit depends on adherence to selection criteria, in particular low-grade tumor biology and Milan criteria, and must be balanced against potential risks of LT.

Association between homologous recombination gene variants and efficacy of oxaliplatin-based chemotherapy in advanced pancreatic cancer: prospective multicenter observational study

Next-generation sequencing (NGS)-based gene profiling can identify patients with pancreatic cancer with homologous recombinant repair gene pathogenic variants (HRRv). Several retrospective studies have reported a positive association between HRRv and the efficacy of platinum-based chemotherapy. However, this association remains to be validated in a prospective study. This multicenter, prospective, observational study included patients with histologically confirmed unresectable or recurrent pancreatic cancer who required systemic chemotherapy. Patients who were oxaliplatin-naïve patients were eligible. The HRRv status was measured using a College of American Pathologists-accredited NGS panel. One-year overall survival rate (1yr-OS%) was calculated after initiation of oxaliplatin-based chemotherapy and was set as the primary endpoint. Forty patients were enrolled between August 2018 and March 2020. The NGS success rate was 95% (38/40). HRRv was detected in 11 patients (27.5%). Oxaliplatin-based chemotherapy was administered to 9 of 11 patients with HRRv (81.8%) and 15 of 29 patients with non-HRRv (51.7%). The 1yr-OS% after initiation of oxaliplatin-based chemotherapy was 44.4% [95% confidence interval (CI) 13.7-71.9] and 57.1% (95% CI 28.4-78.0) in HRRv-positive and -negative cohorts, respectively. These data suggested that HRRv status alone could not be a potential predictive marker of oxaliplatin-based chemotherapy in patients with advanced pancreatic cancer. These results were in line with the results of a recent phase II study reporting the limited efficacy of poly(adenosine diphosphate-ribose) polymerase inhibitor in patients with pancreatic cancer who harbored HRRv other than BRCA. Future studies investigating patients with biallelic HRRv in the first-line setting are warranted.Trial registration UMIN000033655.

Abstract 1511: Origin of synchronous or metachronous multiple pancreatic cancers

Introduction: The majority of patients with pancreatic cancer are inoperable at the time of diagnosis and even those cases with successful tumor resection for early-stage tumors frequently had second tumors within the remaining pancreas shortly after the surgery, contributing to a poor clinical outcome. Moreover, synchronous multiple pancreatic cancers were often reported. One of the long-standing issues about such synchronous and/or metachronous multiple pancreatic cancers is their clonal origins. In this study, we aimed to reveal the origin of multiple pancreatic cancers using an unbiased detection of somatic mutations in primary and metachronous cancers as well as adjacent precursor lesions.

Methods: Serially obtained formalin-fixed paraffin-embedded surgical specimens from 18 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for the enrichment of tumor and precancerous lesions, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. Based on shared and private mutations across different samples, we interrogated history of clonal evolution of these lesions.

Results: We analyzed 18 patients with multiple pancreatic cancers of 2 metachronous and synchronous, 14 metachronous, and 2 synchronous tumors. In metachronous cases, pathology for primary cancer were margin-negative in all patients, and the median interval between the initial and second surgery was 38.9 months (7 - 85 months). In addition, a total of 20 pancreatic intraepithelial neoplasia (PanIN) from 5 of these cases were analyzed. We identified a median of 66 (range: 31-232) and 20 (14-42) somatic mutations in cancer and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In most cases (N=17), sharing many somatic mutations, multiple tumors had a common clonal origin. In another synchronous case, the synchronous tumors shared only one mutation, suggesting that they were clonally independent tumors. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor and cancer lesions. While multiple independent clones were observed in precancerous lesions, most of multiple cancers originated from a common ancestor. Moreover, negative pathology of the margins at the initial surgery suggested that those multiple lesions arose from distant dissemination or metastasis, rather than contiguous, intraductal invasion.

Conclusions: In conclusion, our study suggests that even early pancreatic cancer might be disseminated within the pancreas and contribute to synchronous and metachronous cancers.

Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Yasuhide Takeuchi, Tomomi Nishimura, Toshihiko Masui, Kazuyuki Nagai, Takayuki Anazawa, Sachiko Minamigushi, Hironori Haga, Norimitsu Uza, Hiroshi Seno, Yuzo Kodama, Atsuhiro Masuda, Takeshi Tanaka, Seishi Ogawa, Hiroko Tanaka, Satoru Miyano. Origin of synchronous or metachronous multiple pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1511.

Is frequent measurement of tumor markers beneficial for postoperative surveillance of colorectal cancer?

PURPOSE

To determine whether frequent measurement of tumor markers triggers early detection of colorectal cancer recurrence.

METHODS

Of 1,651 consecutive patients undergoing colorectal cancer surgery between 2010 and 2016, 1,050 were included. CEA and CA 19-9 were considered to be postoperative tumor markers and were measured every 3 months for 3 years, and then every 6 months for 2 years. Sensitivity analysis of elevated CEA and CA19-9 levels and multivariate analysis of factors associated with elevated CEA and CA19-9 levels were performed. The proportion of triggers for detecting recurrence was determined.

RESULTS

The median follow-up period was 5.3 years. After applying the exclusion criteria, 1,050 patients were analyzed, 176 (16.8%) of whom were found to have recurrence. After excluding patients with persistently elevated CEA and CA19-9 levels before and after surgery from the 176 patients, 71 (43.6%) of 163 patients had elevated CEA levels and 35 (20.2%) of 173 patients had elevated CA19-9 levels. Sensitivity/positive predictive values for elevated CEA and CA19-9 levels at recurrence were 43.6%/32.3% and 20.2%/32.4%, respectively. Lymph node metastasis was a factor associated with both elevated CEA and CA19-9 levels at recurrence. Of the 176 patients, computed tomography triggered the detection of recurrence in 137 (78%) and elevated tumor marker levels in 13 (7%); the diagnostic lead interval in the latter 13 patients was 1.7 months.

CONCLUSION

Tumor marker measurements in surveillance after radical colorectal cancer resection contribute little to early detection, and frequent measurements are unnecessary for stage I patients with low risk of recurrence.

Inhibition of Dopamine Receptor D1 Signaling Promotes Human Bile Duct Cancer Progression via WNT signaling

Bile duct cancer (BDC) frequently invades the nerve fibers, making complete surgical resection difficult. A single tumor mass contains cells of variable malignancy and cell-differentiation states, with cancer stem cells (CSCs) considered responsible for poor clinical outcomes. This study aimed to investigate the contribution of autosynthesized dopamine to CSC-related properties in BDC. Sphere formation assays using 13 commercially available BDC cell lines demonstrated that blocking dopamine receptor D1 (DRD1) signaling promoted CSC-related anchorage-independent growth. Additionally, we newly established four new BDC patient-derived organoids (PDOs) and found that blocking DRD1 increased resistance to chemotherapy and enabled xenotransplantation in vivo. Single-cell analysis revealed that the BDC PDO cells varied in their cell-differentiation states and responses to dopamine signaling. Further, DRD1 inhibition increased WNT7B expression in cells with bile duct-like phenotype, and it induced proliferation of other cell types expressing Wnt receptors and stem cell-like signatures. Reagents that inhibited Wnt function canceled the effect of DRD1 inhibition and reduced cell proliferation in BDC PDOs. In summary, in BDCs, DRD1 is a crucial protein involved in autonomous CSC proliferation through the regulation of endogenous WNT7B. As such, inhibition of the DRD1 feedback signaling may be a potential treatment strategy for BDC.

Progress in living donor liver transplantation for biliary atresia and challenges faced: A thirty-year single institutional experience

BACKGROUND

Biliary atresia (BA) is the most common indication for liver transplantation in the pediatric population, and living donor liver transplantation (LDLT) and deceased donor liver transplantation (DDLT) have been established as a radical treatment for BA .The aim of this study was to clarify the long term outcomes and risk factors affecting the LDLT outcomes, as well as the challenges faced.

METHODS

Between 1990 and 2019, 666 BA patients underwent LDLT in our institution and were enrolled in this study. Data regarding the recipient's age, anatomic findings of the biliary tree at Kasai's portoenterostomy, basic characteristics at transplantation, transplant profiles, donor characteristics, and outcomes of LDLT were analyzed.

RESULTS

The 1-, 5-, 10-, 15-, 20-, and 25-year graft survival rates of BA patients who underwent LDLT were 88.1%, 85.4%, 81.5%, 78.9%, 76.6%, and 75.5%, respectively. The transplant era, age at transplantation, ABO incompatible transplant, and presence of pulmonary vascular complications were identified as significant risk factors for overall graft survival. When the study period was divided into the first (1990-1999) and second (2000-2019) phases and re analyzed, the outcomes of ABO-incompatible transplants and LDLT for adult BA patients remained inferior to others in the second phase. The 20-year graft survival rate in patients who underwent re transplantation in the second phase was 54.2%.

CONCLUSIONS

The outcomes of LDLT in children are generally good, but the immunosuppression procedures need to be further improved for ABO-incompatible cases in the future. Further improvements in LDLT results for adult patients and re transplantation remain challenges to be addressed in this field, and future attempts, including revision to the organ allocation system of deceased donors, are necessary.

LEVEL OF EVIDENCE

Level III (case control study).

Potential impact of the adoption of food loss reduction technologies in Indonesia

This study tried to assess the impact of the food loss reduction on Indonesia's economy and environment. The simulation utilises the Computable General Equilibrium (CGE) model, which simulates the effect of food loss technologies adoption in food crops and livestock sectors. The simulation results indicate that the food loss reduction potentially has a positive impact economically and environmentally. From an economic perspective, applying technology to reduce food loss is estimated to increase Indonesia's GDP by 0.37% (around 88 trillion IDR) by 2030 compared to the BAU level. This economic improvement is mostly driven by the increase in household consumption, which can be increased by around 0.47% by 2030. This result follows that around 40% of household incomes in Indonesia are spent on food expenditure. Food loss reduction holds an important key to increasing food availability and household consumption of foods. Our simulation also indicated some positive effects of food loss reduction on the environment. By reducing the food loss, around 14.19 Mt CO2eq of GHG can also be reduced by 2030, while the cropland needed for food crop cultivation can also be reduced by 3.37% by 2030. Finally, this result highlights the importance of food loss reduction for Indonesia's economy and environment. It is recommended that the government pay serious attention to applying food loss reduction technologies to all food crops in the country.

Association between patient's age and the utility of prognostic markers after pancreaticoduodenectomy for pancreatic cancer

BACKGROUND ＆ AIMS: Optimizing treatments balancing prognosis and therapeutic invasiveness is important in the management of pancreatic cancer (PC) owing to global ageing. This study aimed to verify the different utility of biomarkers by patients' age. MATERIALS ＆ METHODS: This is a single-center, retrospective cohort analysis involving 160 patients who undertook pancreaticoduodenectomy (PD) for PC. After comparing clinicopathological factors and survival after PD between aged (≥70 y/o) and young (＜70 y/o) patients, we compared neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), controlling nutrition (CONUT) score, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 as well as clinicopathological factors between long and short survivors in each group. We also performed Kaplan-Meyer analysis between patients stratified by biomarkers. RESULTS: Overall survival (OS) was significantly worse in aged patients (p = 0.002). In aged patients, CEA was significantly higher in short survivors. In young patients, CONUT score and CA19-9 were higher in short survivors. Kaplan-Meyer analysis showed that NLR and CEA stratified OS in aged patients, whereas CONUT score and CA19-9 could stratify OS in young patients. CONCLUSION: Our current results suggest that these biomarkers had different impact on survivals according to the patients' age.

Loss of Arid1a and Pten in Pancreatic Ductal Cells Induces Intraductal Tubulopapillary Neoplasm via the YAP/TAZ Pathway

BACKGROUND & AIMS

Pancreatic ductal adenocarcinoma (PDAC) arises from several types of premalignant lesions, including intraductal tubulopapillary neoplasm (ITPN); however, the molecular pathogenesis of ITPN remains unknown.

METHODS

We performed studies with Hnf1b-CreERT2; Ptenf/f; Arid1af/f mice to investigate the consequence of genetic deletion of Arid1a in adult pancreatic ductal cells in the context of oncogenic PI3K/Akt pathway activation.

RESULTS

Simultaneous deletion of Arid1a and Pten in pancreatic ductal cells resulted in the development of ITPN, which progressed to PDAC, in mice. Simultaneous loss of Arid1a and Pten induced dedifferentiation of pancreatic ductal cells and Yes-associated protein 1/Transcriptional coactivator with PDZ-binding motif (YAP/TAZ) pathway activation. Consistent with the mouse data, TAZ expression was found elevated in human ITPNs and ITPN-derived PDACs but not in human intraductal papillary mucinous neoplasms, indicating that activation of the TAZ pathway is a distinctive feature of ITPN. Furthermore, pharmacological inhibition of the YAP/TAZ pathway suppressed the dedifferentiation of pancreatic ductal cells and development of ITPN in Arid1a and Pten double-knockout mice.

CONCLUSION

Concurrent loss of Arid1a and Pten in adult pancreatic ductal cells induced ITPN and ITPN-derived PDAC in mice through aberrant activation of the YAP/TAZ pathway, and inhibition of the YAP/TAZ pathway prevented the development of ITPN. These findings provide novel insights into the pathogenesis of ITPN-derived PDAC and highlight the YAP/TAZ pathway as a potential therapeutic target.

Pancreatoduodenectomy with portal vein resection for pancreatic body cancer in a patient with situs inversus totalis

BACKGROUND

Situs inversus totalis (SIT) is a rare congenital condition characterized by complete transposition (right-to-left reversal) of the thoracic and abdominal organs. The estimated prevalence of SIT is 1 per 8000-25,000 live births [1]. Surgery for abdominal diseases in patients with SIT is technically demanding because of anatomical variations [2-4]; the importance of preoperative radiological assessment has been reported [4]. We report a case of SIT with complex vascular anomalies and pancreatic body cancer who underwent pancreatoduodenectomy with combined resection of the portal vein.

METHODS

A 79-year-old man with asymptomatic SIT was referred to our hospital for the treatment of pancreatic cancer that was incidentally found during a medical check-up. Abdominal computed tomography (CT) revealed a hypovascular tumor in the pancreatic body with a diameter of 32 mm involving the portal vein. He did not have SIT-associated diseases such as Kartagener syndrome or other malformations but had complex anomalies of vascular anatomy, especially in the hepatic arterial system, in addition to mirror-image transposition.

RESULTS

The operation was performed successfully with a full understanding of the vascular anatomy based on precise preoperative evaluation of CT images, including three-dimensional reconstruction images. The operative time was 710 min, and blood loss was 1237 mL. The Union for International Cancer Control (UICC) pathological stage was Stage III (T2, N2, M0).

CONCLUSION

Pancreatoduodenectomy with portal vein resection for pancreatic cancer in patients with SIT is a complex procedure. Precise preoperative assessment of CT images with three-dimensional reconstruction is crucial to understanding vascular anatomy and safely performing surgery.

Dissecting aneurysm of the proper hepatic artery after laparoscopic hepatectomy possibly related to the Pringle maneuver: A case report

In hepatectomy, the Pringle maneuver is commonly used, but its association with iatrogenic injury is not yet well understood. This report presents a case of dissecting aneurysm of the proper hepatic artery (PHA) possibly associated with the Pringle maneuver during laparoscopic hepatectomy, that was successfully treated by transcatheter arterial embolization (TAE). The patient was a woman in her 70s, and repeat hepatectomy for liver metastasis of rectal neuroendocrine neoplasm was planned. She underwent hand-assisted laparoscopic hepatectomy with the Pringle maneuver. On postoperative day (POD) 7, enhanced computed tomography showed a dissecting aneurysm of the PHA. TAE of the PHA to prevent hemorrhage was performed on POD 9 with no complications. Even after TAE, intrahepatic arterial flow was provided by the peribiliary arteries. This case suggests the possibility that the Pringle maneuver can cause a dissecting aneurysm of the hepatic artery.

Abstract 6198: Genetic analysis of synchronous or metachronous multiple pancreatic cancers

[Introduction] The majority of patients with pancreatic cancer are inoperable at the time of diagnosis and even those cases with successful tumor resection for early-stage tumors frequently had second tumors within the remaining pancreas shortly after the surgery, contributing to a poor clinical outcome. Moreover, synchronous multiple pancreatic cancers were often reported. One of the long-standing issues about such synchronous and/or metachronous multiple pancreatic cancers is their clonal origins. In this study, we aimed to reveal the origin of multiple pancreatic cancers using an unbiased detection of somatic mutations in primary and metachronous cancers as well as adjacent precursor lesions.

[Methods] Serially obtained formalin-fixed paraffin-embedded surgical specimens from 17 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for the enrichment of tumor and precancerous lesions, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. Based on shared and private mutations across different samples, we interrogated history of clonal evolution of these lesions.

[Results] We analyzed 17 patients with multiple pancreatic cancers of 2 metachronous and synchronous, 10 metachronous, and 2 synchronous tumors. In metachronous cases, pathology for primary cancer were margin-negative in all patients, and the median interval between the initial and second surgery was 37.7 months (12 - 85 months). In addition, we analyzed 5 adjacent pancreatic intraepithelial neoplasia (PanIN) in one of these cases. We identified a median of 66 (range: 31-232) and 20 (14-42) somatic mutations in cancer and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In most cases (N=16), sharing many somatic mutations, multiple tumors had a common clonal origin. In another synchronous case, the synchronous tumors shared only one mutation, suggesting that they were clonally independent tumors. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor and cancer lesions. While multiple independent clones were observed in precancerous lesions, most of multiple cancers originated from a common ancestor. Moreover, negative pathology of the margins at the initial surgery suggested that those multiple lesions arose from distant dissemination or metastasis, rather than contiguous, intraductal invasion.

[Conclusions] In conclusion, our study suggests that even early pancreatic cancer might be disseminated within the pancreas and contribute to synchronous and metachronous cancers.

Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Takeuchi Yasuhide, Tomomi Nishimura, Toshihiko Masui, Kazuyuki Nagai, Takayuki Anazawa, Sachiko Minamiguchi, Hironori Haga, Norimitsu Uza, Hiroshi Seno, Yuzo Kodama, Atsuhiro Masuda, Takeshi Tanaka, Yuichi Shiraishi, Satoru Miyano, Seishi Ogawa. Genetic analysis of synchronous or metachronous multiple pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6198.

Impact of Preoperative CEA Uptrend on Survival Outcomes in Patients with Colorectal Liver Metastasis After Hepatectomy

BACKGROUND

Preoperative carcinoembryonic antigen (CEA) has been reported as a prognostic factor in patients with colorectal liver metastasis (CRLM) after hepatectomy. However, the impact of a preoperative "CEA uptrend" on prognosis after hepatectomy in these patients remains unknown. This study assessed the impact of CEA uptrend on prognosis in patients undergoing hepatectomy for CRLM.

METHODS

Consecutive patients with CRLM who underwent hepatectomy between 2009 and 2018 were retrospectively analyzed. Patients with CRLM for whom CEA was measured both around 1 month before (CEA-1m) and within 3 days (CEA-3d) before hepatectomy were enrolled. A CEA-3d higher than both the upper limit of normal (5 ng/ml) and CEA-1m was defined as a CEA uptrend.

RESULTS

Study participants comprised 212 patients with CRLM. Of these, 88 patients (41.5%) showed a CEA uptrend. CEA uptrend indicated better discriminatory ability (corrected Akaike information criteria, 733.72) and homogeneity (likelihood ratio chi-square value, 18.80) than CEA-3d or CEA-1m. Patients with CEA uptrend showed poorer overall survival than those without CEA uptrend (p < 0.001). After adjusting for known prognostic factors, the prognostic significance of CEA uptrend retained (hazard ratio 2.63, 95% confidence interval 1.63-4.26, p < 0.001). In subgroup analyses, the prognostic significance of CEA uptrend was retained irrespective of the status of RAS mutation or response to preoperative chemotherapy.

CONCLUSIONS

CEA uptrend offers better prediction of survival outcomes than conventional CEA measurements in patients undergoing hepatectomy for CRLM.

Establishment of patient-derived organoids and a characterization-based drug discovery platform for treatment of pancreatic cancer

BACKGROUND

Pancreatic cancer is one of the most lethal tumors. The aim of this study is to provide an effective therapeutic discovery platform for pancreatic cancer by establishing and characterizing patient-derived organoids (PDOs).

METHODS

PDOs were established from pancreatic tumor surgical specimens, and the mutations were examined using a panel sequence. Expression of markers was assessed by PCR, immunoblotting, and immunohistochemistry; tumorigenicity was examined using immunodeficient mice, and drug responses were examined in vitro and in vivo.

RESULTS

PDOs were established from eight primary and metastatic tumors, and the characteristic mutations and expression of cancer stem cell markers and CA19-9 were confirmed. Tumorigenicity of the PDOs was confirmed in subcutaneous transplantation and in the peritoneal cavity in the case of PDOs derived from disseminated nodules. Gemcitabine-sensitive/resistant PDOs showed consistent responses in vivo. High throughput screening in PDOs identified a compound effective for inhibiting tumor growth of a gemcitabine-resistant PDO xenograft model.

CONCLUSIONS

This PDO-based platform captures important aspects of treatment-resistant pancreatic cancer and its metastatic features, suggesting that this study may serve as a tool for the discovery of personalized therapies.

Increased Expressions of Programmed Death Ligand 1 and Galectin 9 in Transplant Recipients Who Achieved Tolerance After Immunosuppression Withdrawal

Programmed death 1 (PD1)/its ligand PD-L1 concomitant with T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3)/its ligand galectin 9 (Gal-9) and the forkhead box P3 (FOXP3) might be involved in tolerance after liver transplantation (LT). Liver biopsies from 38 tolerant, 19 nontolerant (including 16 samples that triggered reintroduction of immunosuppression [IS] and 19 samples after IS reintroduction), and 38 control LT patients were studied. The expressions of PD1, PD-L1, Gal-9, and FOXP3 were determined by immunohistochemical and immunofluorescence (IF) staining. The success period of IS withdrawal was calculated using Kaplan-Meier curve analysis. Tolerant and control patients exhibited higher PD-L1, Gal-9, and FOXP3 levels than nontolerant patients at the moment of triggering IS reintroduction. High expressions of PD-L1 and Gal-9 were associated with prolonged success of tolerance (83.3% versus 36.7% [P < 0.01] and 73.1% versus 42.9% [P = 0.03]). A strong correlation between PD-L1 and Gal-9 expression levels was detected (Spearman r = 0.73; P ≤ 0.001), and IF demonstrated colocalization of PD-L1 and Gal-9 in the cytoplasm of hepatocytes. In conclusion, the present study demonstrated that increased expressions of PD-L1 and Gal-9 were associated with sustained tolerance after IS withdrawal in pediatric liver transplantation.

Nationwide registry for patients with neuroendocrine neoplasm of pancreas, gastrointestinal tract, lungs, bronchi, or thymus in Japan

BACKGROUND

Neuroendocrine neoplasm (NEN) is a comparatively rare tumor that has been considered indolent. Due to these characteristics, detailed epidemiological data have not been analyzed in Japan. To elucidate the present status of NEN diagnosis and treatment in Japan, we started a registry cohort study in January 2015.

METHODS

Patients pathologically diagnosed with NENs of the pancreas, gastrointestinal tract, lungs, bronchi, or thymus after January 2012 were enrolled in this registry after the date of ethics review committee approval in each hospital or institute. Follow-up was continued for enrolled patients.

RESULTS

During 5 years of enrollment between January 2015 and December 2019, a total of 1526 participants from 63 departments were enrolled in this registry (mean, 305.2 participants/year), covering approximately 5.8% of the annual incidence of NENs in Japan. For pancreatic NEN, 41.9% of patients had metastasis and the dominant metastatic site was the liver, at twice the rate of lymph node metastasis in the current registry. In contrast, the frequency of lymph node metastasis from gastrointestinal (GI)-NEN was similar to that of the liver. The distribution of WHO 2019-based grades varied according to the primary site. Low-to-intermediate grade (G1-G2) was dominant for duodenal, jejunal/ileal, rectal, and pancreatic NENs, whereas high grade (G3 or NEC) was dominant for esophageal, stomach, and colon NENs. For PanNENs, G3 and NEC accounted only for 1.6% and 2.9%, respectively.

CONCLUSIONS

These cohort data provide crucial information for clinical research to clarify the characteristics of NENs in Japan.

Pathogenic variants of homologous recombination repair-related genes in advanced pancreatic cancer and oxaliplatin-based chemotherapy: Prospective multicenter observational study

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Background: The latest National Comprehensive Cancer Network Guidelines for pancreatic adenocarcinoma recommended platinum-based chemotherapy for the patients with germline BRCA1/2 or PALB2 variants based on retrospective studies. However, the association between the efficacy of oxaliplatin-based chemotherapy and homologous recombination repair (HRR)-related gene variants has not yet been evaluated in a prospective study. Methods: This was a multicenter, prospective, observational study. Key inclusion criteria were: histologically confirmed pancreatic adenocarcinoma or adenosquamous carcinoma; candidates for systemic chemotherapy or currently under systemic chemotherapy for unresectable disease; age ≥ 20 years; Eastern Cooperative Oncology Group Performance Status 0–2; formalin-fixed paraffin-embedded cancer tissue available for genomic sequencing; and adequate hematological, liver, and renal function. Patients were assessed with the next generation sequencing (NGS)-based ACT-repair panel (ACT genomics; Taipei, Taiwan). ACT-repair panel is accredited by College of American Pathologists and is designed to detect short variants (SVs) including substitutions, insertions, deletions, and copy number variants of 35 genes including 8 HRR-related genes ( ATM, ATR, BRCA1, BRCA2, PALB2, RAD51B, RAD51C, RAD51D). The primary endpoint was the one-year overall survival rate (1yr-OS%) after the initiation of oxaliplatin-based chemotherapy in patients who harbored pathogenic HRR gene variants. On the basis of published retrospective data, expected 1yr-OS% was set at ≥ 60% in this study. Results: Forty patients were enrolled from August 2018 to March 2020. Median age was 67 years (range, 49–81 years). Sequencing data were obtained from 39 patients (NGS success rate = 97.5%). Nine patients (22.5%) harboring HRR gene; ATM SVs (n = 4), BRCA2 loss of heterozygosity (LOH) (n = 3), BRCA2 SVs (n = 1), and PALB2 LOH (n = 1). Three patients received oxaliplatin-based chemotherapy as first-line chemotherapy, while the remaining six patients received it as second- or later-line oxaliplatin-based chemotherapy. The 1yr-OS% was 44.4%, and the median overall survival was 221 days (95% confidence interval, 79–NA days) after the initiation of oxaliplatin-based chemotherapy. In three patients who received oxaliplatin-based chemotherapy as first-line treatment, overall survivals were 703 (alive), 694 (alive), and 405 (dead) days, respectively. Conclusions: Efficacy of oxaliplatin-based chemotherapy on advanced pancreatic cancer harboring HRR-related gene variants did not meet the primary endpoint of 1yr-OS% (≥ 60%). Clinical trial information: UMIN000033655.

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.

SNAIL2 contributes to tumorigenicity and chemotherapy resistance in pancreatic cancer by regulating IGFBP2

Pancreatic cancer has an extremely poor prognosis because of its resistance to conventional therapies. Cancer stem cell (CSC)-targeted therapy is considered a promising approach for this disease. Epithelial-mesenchymal transition-inducing transcription factors (EMT-TFs) contribute to CSC properties in some solid tumors; however, this mechanism has not been fully elucidated in pancreatic cancer. Zinc finger protein, SNAIL2 (also known as SLUG), is a member of the SNAIL superfamily of EMT-TFs and is commonly overexpressed in pancreatic cancer. Patients exhibiting high SNAIL2 expression have a poor prognosis. In this study, we showed that the suppression of SNAIL2 expression using RNA interference decreased tumorigenicity in vitro (sphere formation assay) and in vivo (xenograft assay) in 2 pancreatic cancer cell lines, KLM1 and KMP5. In addition, SNAIL2 suppression resulted in increased sensitivity to gemcitabine and reduced the expression of CD44, a pancreatic CSC marker. Moreover, experiments on tumor spheroids established from surgically resected pancreatic cancer tissues yielded similar results. A microarray analysis revealed that the mechanism was mediated by insulin-like growth factor (IGF) binding protein 2. These results indicate that IGFBP2 regulated by SNAIL2 may represent an effective therapeutic target for pancreatic cancer.

JNETS clinical practice guidelines for gastroenteropancreatic neuroendocrine neoplasms: diagnosis, treatment, and follow-up: a synopsis

Neuroendocrine neoplasms (NENs) are rare neoplasms that occur in various organs and present with diverse clinical manifestations. Pathological classification is important in the diagnosis of NENs. Treatment strategies must be selected according to the status of differentiation and malignancy by accurately determining whether the neoplasm is functioning or nonfunctioning, degree of disease progression, and presence of metastasis. The newly revised Clinical Practice Guidelines for Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs) comprises 5 chapters-diagnosis, pathology, surgical treatment, medical and multidisciplinary treatment, and multiple endocrine neoplasia type 1 (MEN1)/von Hippel-Lindau (VHL) disease-and includes 51 clinical questions and 19 columns. These guidelines aim to provide direction and practical clinical content for the management of GEP-NEN preferentially based on clinically useful reports. These revised guidelines also refer to the new concept of "neuroendocrine tumor" (NET) grade 3, which is based on the 2017 and 2019 WHO criteria; this includes health insurance coverage of somatostatin receptor scintigraphy for NEN, everolimus for lung and gastrointestinal NET, and lanreotide for GEP-NET. The guidelines also newly refer to the diagnosis, treatment, and surveillance of NEN associated with VHL disease and MEN1. The accuracy of these guidelines has been improved by examining and adopting new evidence obtained after the first edition was published.

How ICT can contribute to realize a sustainable society in the future: a CGE approach

Many information and communications technology (ICT) services have become commonplace worldwide and are certain to continue to spread faster than before, particularly along with the commercialization of 5G and movement restrictions in response to the COVID-19 Pandemic. Although there is a concern that ICT equipment usage may increase power consumption and emit greenhouse gas (GHG) emissions, ICT has also been contributing to reducing GHG emissions through improved productivity and reduced mobility. This research targeted the main ICT services used in Japan and adopted a dynamic national computable general equilibrium model to quantitatively analyze future impacts on economic growth and GHG emission reduction until 2030 by using these ICTs, while considering both the increase in power consumption of ICT itself and the reduction in environmental load in other sectors. The results showed that the spread of ICT services, especially some artificial intelligence-based services, can improve productivity in most sectors through labor-saving and contribute to improving overall gross domestic product (GDP). Additionally, increased efficiency of logistics and manufacturing can greatly reduce the input of oil and coal products and so greatly contribute to GHG emission reduction. In 2030, compared with the baseline scenario in which all technology levels are fixed at current levels, at least 1% additional GDP growth and 4% GHG emission reduction can be expected by the targeted introduction of ICT in the ICT accelerated scenario in which the technology level of ICT accelerates. This also means ICT can potentially decouple the economy from the environment.

Extreme climate events increase risk of global food insecurity and adaptation needs

Climate change is expected to increase the frequency, intensity and spatial extent of extreme climate events, and thus is a key concern for food production. However, food insecurity is usually analysed under a mean climate change state. Here we combine crop modelling and climate scenarios to estimate the effects of extreme climate events on future food insecurity. Relative to median-level climate change, we find that an additional 20-36% and 11-33% population may face hunger by 2050 under a once-per-100-yr extreme climate event under high and low emission scenarios, respectively. In some affected regions, such as South Asia, the amount of food required to offset such an effect is triple the region's current food reserves. Better-targeted food reserves and other adaptation measures could help fill the consumption gap in the face of extreme climate variability.

Abstract 2185: Genetic analysis of metachronous pancreatic cancers

[Introduction] Early detection of pancreatic cancer is a key to curable surgery. However, many patients are diagnosed with an advanced disease and even in those who have an early stage tumor successfully resected, the development of metachronous cancer in the residual pancreas prevents a long-term survival. Thus, it is important to control metachronous tumors to improve clinical outcomes, whose pathogenesis, however, is poorly understood. In this study, we aimed to reveal the origin of metachronous tumors using an unbiased detection of somatic mutations in primary and metachronous tumors as well as adjacent precursor lesions.

[Methods] Serially obtained formalin-fixed paraffin-embedded surgical specimens from 12 patients who had undergone curative surgery for an early-stage pancreatic cancer were subjected to laser microdissection for enrichment of tumor and precancerous components, from which DNA was extracted and analyzed for somatic mutations using whole-exome sequencing (WES) with matched normal DNA. Based on shared and private mutations across different samples, we interrogated history of clonal evolution of these lesions.

[Results] Pathology for resected primary cancer was margin-negative in all patients. The median interval between the initial and second surgery was 34.6 months (12 - 65.1 months). Paired primary and metachronous cancers were analyzed in all 12 patients. An additional 5 pancreatic intraepithelial neoplasia (PanIN) samples were also analyzed in one case. We identified a median of 86 (range: 40-145) and 20 (14-42) somatic mutations using WES in cancers and PanIN lesions, respectively. None of the patients have known pathogenic germline variants. All samples had one or more driver mutations. In each patient, all driver mutations and many passenger mutations were shared between primary and metachronous cancer samples, suggesting that those metachronous tumors are evolutionally closely related to the primary cancer, despite long years before recurrence. Negative pathology of the margins at the initial surgery suggested that those metachronous lesions originated from distant dissemination or metastasis, rather than contiguous, intraductal invasion. By contrast, none of the mutations other than hotspot KRAS mutations were shared between precursor lesions and cancer samples. Despite multiple independent clones in the precancerous lesion, all metachronous tumors originated from the primary lesions in this study.

[Conclusions] Our study suggests that even early pancreatic cancer might be disseminated within the pancreas and give rise to metachronous cancers, suggesting the importance of close monitoring of recurrence in the residual pancreas.

Citation Format: Tomonori Hirano, Nobuyuki Kakiuchi, Yasuhide Takeuchi, Tomomi Nishimura, Toshihiko Masui, Sachiko Minamiguhi, Hironori Haga, Kenichi Chiba, Hiroko Tanaka, Yuichi Shiraishi, Satoru Miyano, Uza Norimitsu, Yuzo Kodama, Hiroshi Seno, Seishi Ogawa. Genetic analysis of metachronous pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2185.

Survey of surgical resections for neuroendocrine liver metastases: A project study of the Japan Neuroendocrine Tumor Society (JNETS)

BACKGROUND/PURPOSE

Hepatic resection is considered the treatment of choice for neuroendocrine liver metastases (NELM). However, the safety and efficacy of resection have not been fully evaluated using a large cohort. The aim of the present study was to collect real-world data regarding hepatic resections for NELM.

METHODS

A retrospective, multicenter survey was conducted. The background characteristics of patients undergoing an initial hepatic resection for NELM, the operative details, pathological findings, and patient outcomes were investigated.

RESULTS

A total of 222 patients were enrolled from 30 institutions. The primary tumor site was the pancreas in 58.6%, and the presentation of NELM was synchronous in 63.1% of the cases. Concomitant resection of the primary tumor and liver metastases was performed for 66.4% of the synchronous metastases, and the 90-day morbidity and mortality rates were 12.6% and 0.9%, respectively. The operations resulted in R2 resections in 26.1% of the cases, and 83.4% of the patients experienced recurrence after R0/1 resections. However, the patients were treated using multiple modalities after R2 resection or recurrence, and the overall survival rate was relatively favorable, with 5-year and 10-year survival rates of 70.2%, and 43.4%, respectively. Univariable and multivariable analyses identified the tumor grading (G3) of the primary tumor as a significant prognostic factor for both the recurrence-free and overall survivals.

CONCLUSIONS

The present data confirmed the safety of the surgical resection of NELM. Although recurrences were frequent, the survival outcomes after resection were favorable when a multi-disciplinary treatment approach was used.

CGE modeling with disaggregated pollution treatment sectors for assessing China's environmental tax policies

This research involved constructing a computable general equilibrium (CGE) model for assessing China's latest environmental tax policies. Most environmental CGE models link pollutant emissions to the standard CGE model only by pollution coefficients per unit of sectoral output, and the emission reduction process is not included within production structures. We constructed separate pollution treatment sectors for solid waste management, wastewater management, and waste gas management to describe the pollution treatment processes and identify how policies affect production activities. We compiled the satellite accounts of 18 pollutants from the China Environmentally Extended Input-Output (CEEIO) dataset covering primary gas, water, and solid pollutants and disaggregated the electricity sector into six different production technologies: hydroelectricity, coal power, gas electricity, oil electricity, nuclear power, and renewable energies. We drew two primary conclusions from the simulation results. First, the environmental policies examined could help reduce the emissions of most kinds of pollutants, but also negatively affect GDP. GDP loss by 2030 would be 0.03% in the low environmental tax scenario (LowET), 0.06% in the high environmental tax scenario (HighET), 0.16% in the low environmental tax and low carbon tax scenario (LowETC), and 0.34% in the high environmental tax and high carbon tax scenario (HighETC). SO₂ emissions would decrease by 17.4%, 21.0%, 19.3% and 24.5%, respectively, and CO₂ emissions would reduce by 0.9%, 1.7%, 5.8% and 11.0%. Second, despite the minor changes in the economic impacts, the effectiveness in pollution treatment of environmental tax policies is underestimated if the pollution treatment sectors are disaggregated in the CGE model. Take the SO₂ for an example. The calculated SO₂ reductions will increase from 8.95% to 24.46% after disaggregating the pollution treatment sectors in HighETC scenarios.

A subcentimeter duodenal neuroendocrine neoplasm with a liver metastasis upgraded to G3: a case report

BACKGROUND

Although duodenal neuroendocrine neoplasms (DuNENs) usually have indolent phenotypes, some DuNENs exhibit aggressive clinical manifestations. Tumor size > 1 cm, lymph node metastasis, and high grade have been associated with poor prognosis. However, preoperative risk evaluation is often difficult, because Ki-67 index on biopsy is frequently underestimated due to the intratumor heterogeneity. Here, we present a case of a subcentimeter DuNEN with a low Ki-67 index on endoscopic biopsy, who developed lymph node metastasis and high-grade liver metastasis.

CASE PRESENTATION

The patient was a 52-year-old female who presented an epigastric pain. Esophagogastroduodenoscopy revealed a duodenal submucosal lesion with a size of 8 mm. The endoscopic biopsy showed DuNEN with a Ki-67 index of 3.3% (G2 categorized by the World Health Organization 2019 classification). We performed an open partial duodenectomy with adjacent lymph node dissection. Pathological examination of the resected specimens revealed a Ki-67 index of 13.5% (G2) in the "hot spot" and lymph node metastasis. A hepatic low-density area detected on preoperative contrast-enhanced computed tomography appeared to be a liver metastasis on postoperative gadoxetic acid-enhanced magnetic resonance imaging. Subsequently, we performed a laparoscopic partial hepatectomy. Pathological examination of the liver specimen showed a metastatic neuroendocrine tumor with a Ki-67 index of 27.5% (NET-G3). The patient has been alive for 14 months since the hepatectomy.

CONCLUSIONS

This case shows the possibility of high malignant potential of DuNEN even if the primary lesion is < 1 cm and has a low Ki-67 index on biopsy.

Potential impact of introducing emission mitigation policies in Indonesia: how much will Indonesia have to spend?

Under the Nationally Determined Commitment (NDC), Indonesia voluntarily reduces GHG emission by 29% compared to the BAU level in 2030. While the national economics itself is still growing and advancing, the mitigation policies are expected to slow down the economy at some level. This study is trying to examine the potential impact of the emission mitigation policies on the Indonesian economy by utilizing a dynamic computable general equilibrium (CGE). The simulation result showed that the implementation of comprehensive mitigation technology would cause a GDP loss of around 1.7% by 2030 compared to the BAU level. If we look at the sectoral GDP, the agriculture sector is projected to experiencing the most significant shock by the emission mitigation policies (- 13.4% compared to BAU level by 2030). But the energy sector might become a sector experiencing higher GDP under the mitigation action (3.5% compared to BAU level by 2030). It also showed that the utilization of renewable energies for power generation would increase significantly, especially after 2025, but still cannot fully replace the dominance of fossil fuel sources. There are several policy recommendations based on our simulation results, including that the government also needs to increase efficiency in using fossil fuels, especially coal and gas, during the process of building infrastructure for renewable energy utilization. In terms of employment, the government needs to prepare other sectors to absorb labor, especially from the agricultural sector. Another crucial thing is that considering the possible economic impact, especially in the mid-term period, the government needs to implement necessary mitigation policies immediately. Otherwise, the government may need to prepare more expenditure to introduce more technologies and policies in the future.

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.

Recent epidemiology of patients with gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NEN) in Japan: a population-based study

Background

The worldwide prevalence and incidence of neuroendocrine neoplasms (NEN) have been increasing recently, although few studies have analyzed data on the current situation of NENs in Japan. Here, the Japan Neuroendocrine Tumor Society (JNETS) planned to investigate the recent incidence and distribution of these tumors using data from the national cancer registry started in 2016. This study examined the incidence and distribution of primary sites as well as rate of advanced disease from this population-based registry.

Methods

A retrospective, population-based study using data from the national cancer registry in Japan (NCR) was conducted to evaluate patients with gastro-entero-pancreatic NEN (GEP-NEN) in 2016. Associated population data were used to determine annual age-adjusted incidences.

Results

A total of 6735 individuals were diagnosed with GEP-NEN in Japan in 2016. Annual onset incidence was 0.70/100,000 for pancreatic NEN and 2.84/100,000 for gastrointestinal NEN. NEN in the ileum accounted for only 1% of total GEP-NENs in Japan. Most NENs in the esophagus or lungs were neuroendocrine carcinomas (NECs), while the majority of those in the duodenum, ileum, appendix and rectum were grade 1 neuroendocrine tumors (NETs). Median age at initial diagnosis was in between 60 to 65. Tumors in the duodenum, appendix and rectum were mostly limited to local, while those in the esophagus, stomach and colon tended to show distant metastasis. In Japan, initial treatment for GEP-NENs was resection even if the tumor was NEC.

Conclusions

This is the first report of a national registry-based incidence and distribution of GEP-NEN in Japan. These data will serve as an important first step to determining the exact etiology and trends for this pathology in Japan.

Hypofractionated intensity-modulated radiotherapy with concurrent chemotherapy for elderly patients with locally advanced pancreatic carcinoma

BACKGROUND

It is important to understand how elderly patients with locally advanced pancreatic carcinoma (LAPC) should be treated, since the number of elderly cancer patients will increase. However, the optimal treatment for elderly patients with LAPC remains unclear. The purpose of this study was to evaluate the efficacy and safety of hypofractionated intensity-modulated radiotherapy (IMRT) with concurrent gemcitabine for elderly patients with LAPC.

METHODS

We retrospectively analysed the data from LAPC patients aged ≥ 75 years treated with hypofractionated IMRT (48 Gy in 15 fractions) with concurrent weekly gemcitabine at our institution from February 2013 to December 2018. Overall survival (OS), progression-free survival (PFS), locoregional progression-free survival (LRPFS), distant metastasis-free survival (DMFS), and the pattern of recurrence and toxicity were analysed.

RESULTS

Fifteen patients received treatment during the study period. The median age was 78 years (range 75-86 years), and the Eastern Cooperative Oncology Group (ECOG) performance status (PS) of all patients was 0-1. The median survival time (MST) and median PFS were 20.4 [95% confidence interval (CI) 10.3-36.8] and 13.5 (95% CI 6.4-20.3) months, respectively, and the 1-year OS and PFS rates were 80.0% (95% CI 50-93.1%) and 66.7% (95% CI 37.5-84.6%), respectively. The median LRPFS and median DMFS were 15.6 (95% CI 6.4-36.8) and 14.9 (95% CI 7.0-20.5) months, respectively, and the 1-year LRPFS and DMFS rates were 73.3% (95% CI 43.6-89.1%) and 66.7% (95% CI 37.5-84.6%), respectively. Non-haematologic grade 3 toxicity was observed in three cases, of which only one was induced by radiotherapy, whereas grade 4-5 non-haematologic acute or late toxicities were not observed.

CONCLUSIONS

The OS and PFS of elderly patients with LAPC treated using hypofractionated IMRT with concurrent gemcitabine were favourable and without the occurrence of severe toxicity. This treatment strategy is feasible and promising for elderly LAPC patients with good PS.

Liver Transection-First Approach in Hepatopancreatoduodenectomy for Hilar Cholangiocarcinoma: A Safe and Secure Technique for the Early Assessment of Curable Resection and Vascular Reconstruction

BACKGROUND

Hepatopancreatoduodenectomy (HPD) is often indicated in the resection of cholangiocarcinoma but is associated with high mortality.1-3 From a risk-benefit perspective, HPD can be justified only when curative resection is achievable.4-6 METHODS: A liver transection-first approach is a surgical technique in which liver transection precedes pancreatoduodenectomy (PD) and skeletonization of the hepatoduodenal ligament in HPD. This approach enables an early assessment of resectability and curability.

RESULTS

A 64-year-old with jaundice had a tumor located mainly in the proximal bile duct, spreading from the confluence of hepatic ducts (dominant in the left hepatic duct) to the intrapancreatic bile duct. The right hepatic artery and portal vein existed in close proximity to the tumor. HPD (left hemi-hepatectomy and subtotal stomach-preserving PD) with vascular resection was performed. After liver transection along the Cantlie line, the right Glissonean pedicle was collectively secured inside the liver. The right hepatic artery, right portal vein, and right hepatic duct (RHD) were isolated, and the feasibility of vascular reconstruction was confirmed. After the RHD was divided and the negative margin was confirmed, we proceeded to perform PD. The portal vein was reconstructed between the right portal vein and the portal vein trunk. The right hepatic artery was anastomosed to the second jejunal artery of the jejunal loop with the right gastroepiploic artery as an interposition graft.

CONCLUSION

The liver transection-first technique in HPD facilitates early assessment of curability and resectability as well as a safe and secure manipulation and reconstruction of the hepatic artery and portal vein.

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.