Blockade of histamine receptor H1 augments immune checkpoint therapy by enhancing MHC-I expression in pancreatic cancer cells.

BACKGROUND: Although immune checkpoint blockade (ICB) therapy has proven to be extremely effective at managing certain cancers, its efficacy in treating pancreatic ductal adenocarcinoma (PDAC) has been limited. Therefore, enhancing the effect of ICB could improve the prognosis of PDAC. In this study, we focused on the histamine receptor H1 (HRH1) and investigated its impact on ICB therapy for PDAC. METHODS: We assessed HRH1 expression in pancreatic cancer cell (PCC) specimens from PDAC patients through public data analysis and immunohistochemical (IHC) staining. The impact of HRH1 in PCCs was evaluated using HRH1 antagonists and small hairpin RNA (shRNA). Techniques including Western blot, flow cytometry, quantitative reverse transcription polymerase chain reaction (RT-PCR), and microarray analyses were performed to identify the relationships between HRH1 and major histocompatibility complex class I (MHC-I) expression in cancer cells. We combined HRH1 antagonism or knockdown with anti-programmed death receptor 1 (αPD-1) therapy in orthotopic models, employing IHC, immunofluorescence, and hematoxylin and eosin staining for assessment. RESULTS: HRH1 expression in cancer cells was negatively correlated with HLA-ABC expression, CD8+ T cells, and cytotoxic CD8+ T cells. Our findings indicate that HRH1 blockade upregulates MHC-I expression in PCCs via cholesterol biosynthesis signaling. In the orthotopic model, the combined inhibition of HRH1 and αPD-1 blockade enhanced cytotoxic CD8+ T cell penetration and efficacy, overcoming resistance to ICB therapy. CONCLUSIONS: HRH1 plays an immunosuppressive role in cancer cells. Consequently, HRH1 intervention may be a promising method to amplify the responsiveness of PDAC to immunotherapy.

Genomic Profiling of Rare Undifferentiated Sarcomatoid Subtypes of Pancreatic Carcinomas: In Search of Therapeutic Targets.

PURPOSE: The highly aggressive undifferentiated sarcomatoid carcinoma (USC) subtype of pancreatic ductal adenocarcinoma (PDAC) remains poorly characterized because of its rarity. Previous case reports suggest that immune checkpoint inhibitors could be a promising treatment strategy, but the prevalence of established predictive biomarkers of response is largely unknown. The objective of this study was to leverage comprehensive genomic profiling of USC PDAC tumors to determine the prevalence of biomarkers associated with potential response to targeted therapies. METHODS: USC tumors (n = 20) underwent central pathology review by a board-certified gastrointestinal pathologist to confirm the diagnosis. These samples were compared with non-USC PDAC tumors (N = 5,562). Retrospective analysis of DNA and RNA next-generation sequencing data was performed. RESULTS: USC PDACs were more frequently PD-L1+ by immunohistochemistry than non-USC PDAC (63% v 16%, respectively, P < .001). Furthermore, USC PDAC had an increase in neutrophils (8.99% v 5.55%, P = .005) and dendritic cells (1.08% v 0.00%, q = 0.022) and an increased expression of PDCD1LG2 (4.6% v 1.3%, q = 0.001), PDCD1 (2.0% v 0.8%, q = 0.060), and HAVCR2 (45.9% v 21.7%, q = 0.107) than non-USC PDAC. Similar to non-USC PDAC, KRAS was the most commonly mutated gene (86% v 90%, respectively, P = 1). CONCLUSION: To our knowledge, this work represents the largest molecular analysis of USC tumors to date and showed an increased expression of immune checkpoint genes in USC tumors. These findings provide evidence for further investigation into immune checkpoint inhibitors in USC tumors.

A rat-based preclinical platform facilitating transcatheter hepatic arterial infusion in immunodeficient rats with liver xenografts of patient-derived pancreatic ductal adenocarcinoma.

Liver metastases from pancreatic ductal adenocarcinoma (PDAC) are highly fatal. A rat-based patient-derived tumor xenograft (PDX) model is available for transcatheter therapy. This study aimed to create an immunodeficient rat model with liver xenografts of patient-derived primary PDAC and evaluate efficacy of hepatic arterial infusion chemotherapy with cisplatin in this model. Three patient-derived PDACs were transplanted into the livers of 21 rats each (totally, 63 rats), randomly assigned into hepatic arterial infusion, systemic venous infusion, and control groups (n = 7 each) four weeks post-implantation. Computed tomography evaluated tumor volumes before and four weeks after treatment. Post-euthanasia, resected tumor specimens underwent histopathological examination. A liver-implanted PDAC PDX rat model was established in all 63 rats, with first CT identifying all tumors. Four weeks post-treatment, arterial infusion groups exhibited significantly smaller tumor volumes than controls for all three tumors on second CT. Xenograft tumors histologically maintained adenocarcinoma features compared to original patient tumors. Ki67 expression was significantly lower in arterial infusion groups than in the other two for the three tumors, indicating reduced tumor growth in PDX rats. A liver-implanted PDAC PDX rat model was established as a rat-based preclinical platform. Arterial cisplatin infusion chemotherapy represents a potential therapy for PDAC liver metastasis.

The Effect of Intratumor Heterogeneity in Pancreatic Ductal Adenocarcinoma Progression and Treatment.

BACKGROUND AND OBJECTIVES: Pancreatic cancer is one of the most lethal malignancies. Even though many substantial improvements in the survival rates for other major cancer forms were made, pancreatic cancer survival rates have remained relatively unchanged since the 1960s. Even more, no standard classification system for pancreatic cancer is based on cellular biomarkers. This review will discuss and provide updates about the role of stem cells in the progression of PC, the genetic changes associated with it, and the promising biomarkers for diagnosis. MATERIALS AND METHODS: The search process used PubMed, Cochrane Library, and Scopus databases to identify the relevant and related articles. Articles had to be published in English to be considered. RESULTS: The increasing number of studies in recent years has revealed that the diversity of cancer-associated fibroblasts is far greater than previously acknowledged, which highlights the need for further research to better understand the various cancer-associated fibroblast subpopulations. Despite the huge diversity in pancreatic cancer, some common features can be noted to be shared among patients. Mutations involving CDKN2, P53, and K-RAS can be seen in a big number of patients, for example. Similarly, some patterns of genes and biomarkers expression and the level of their expression can help in predicting cancer behavior such as metastasis and drug resistance. The current trend in cancer research, especially with the advancement in technology, is to sequence everything in hopes of finding disease-related mutations. CONCLUSION: Optimizing pancreatic cancer treatment requires clear classification, understanding CAF roles, and exploring stroma reshaping approaches.

Positive feedback regulation between glycolysis and histone lactylation drives oncogenesis in pancreatic ductal adenocarcinoma.

BACKGROUND: Metabolic reprogramming and epigenetic alterations contribute to the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). Lactate-dependent histone modification is a new type of histone mark, which links glycolysis metabolite to the epigenetic process of lactylation. However, the role of histone lactylation in PDAC remains unclear. METHODS: The level of histone lactylation in PDAC was identified by western blot and immunohistochemistry, and its relationship with the overall survival was evaluated using a Kaplan-Meier survival plot. The participation of histone lactylation in the growth and progression of PDAC was confirmed through inhibition of histone lactylation by glycolysis inhibitors or lactate dehydrogenase A (LDHA) knockdown both in vitro and in vivo. The potential writers and erasers of histone lactylation in PDAC were identified by western blot and functional experiments. The potential target genes of H3K18 lactylation (H3K18la) were screened by CUT&Tag and RNA-seq analyses. The candidate target genes TTK protein kinase (TTK) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were validated through ChIP-qPCR, RT-qPCR and western blot analyses. Next, the effects of these two genes in PDAC were confirmed by knockdown or overexpression. The interaction between TTK and LDHA was identified by Co-IP assay. RESULTS: Histone lactylation, especially H3K18la level was elevated in PDAC, and the high level of H3K18la was associated with poor prognosis. The suppression of glycolytic activity by different kinds of inhibitors or LDHA knockdown contributed to the anti-tumor effects of PDAC in vitro and in vivo. E1A binding protein p300 (P300) and histone deacetylase 2 were the potential writer and eraser of histone lactylation in PDAC cells, respectively. H3K18la was enriched at the promoters and activated the transcription of mitotic checkpoint regulators TTK and BUB1B. Interestingly, TTK and BUB1B could elevate the expression of P300 which in turn increased glycolysis. Moreover, TTK phosphorylated LDHA at tyrosine 239 (Y239) and activated LDHA, and subsequently upregulated lactate and H3K18la levels. CONCLUSIONS: The glycolysis-H3K18la-TTK/BUB1B positive feedback loop exacerbates dysfunction in PDAC. These findings delivered a new exploration and significant inter-relationship between lactate metabolic reprogramming and epigenetic regulation, which might pave the way toward novel lactylation treatment strategies in PDAC therapy.

Adjuvant chemotherapy omission after pancreatic cancer resection: a French nationwide study.

BACKGROUND: Adjuvant chemotherapy (AC) improves the prognosis after pancreatic ductal adenocarcinoma (PDAC) resection. However, previous studies have shown that a large proportion of patients do not receive or complete AC. This national study examined the risk factors for the omission or interruption of AC. METHODS: Data of all patients who underwent pancreatic surgery for PDAC in France between January 2012 and December 2017 were extracted from the French National Administrative Database. We considered "omission of adjuvant chemotherapy" (OAC) all patients who failed to receive any course of gemcitabine within 12 postoperative weeks and "interruption of AC" (IAC) was defined as less than 18 courses of AC. RESULTS: A total of 11 599 patients were included in this study. Pancreaticoduodenectomy was the most common procedure (76.3%), and 31% of the patients experienced major postoperative complications. OACs and IACs affected 42% and 68% of the patients, respectively. Ultimately, only 18.6% of the cohort completed AC. Patients who underwent surgery in a high-volume centers were less affected by postoperative complications, with no impact on the likelihood of receiving AC. Multivariate analysis showed that age ≥ 80 years, Charlson comorbidity index (CCI) ≥ 4, and major complications were associated with OAC (OR = 2.19; CI95%[1.79-2.68]; OR = 1.75; CI95%[1.41-2.18] and OR = 2.37; CI95%[2.15-2.62] respectively). Moreover, age ≥ 80 years and CCI 2-3 or ≥ 4 were also independent risk factors for IAC (OR = 1.54, CI95%[1.1-2.15]; OR = 1.43, CI95%[1.21-1.68]; OR = 1.47, CI95%[1.02-2.12], respectively). CONCLUSION: Sequence surgery followed by chemotherapy is associated with a high dropout rate, especially in octogenarian and comorbid patients.

Dysregulated BH4 metabolism facilitates immunosuppression in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive, malignant, and lethal cancers, displaying strong resistance to immunotherapy. In this issue of Cell Metabolism, a study by Liu et al. identifies tetrahydrobiopterin metabolic dysregulation as a key driver for the immunosuppressive PDAC environment in mouse and human.

Pancreatic GHRHomas in Patients with or without Multiple Endocrine Neoplasia Type 1 (MEN 1) : An Analysis of 36 Reported Cases.

Pancreatic GHRHomas (pGHRHomas) with acromegaly have unique conditions, harboring the existence of multiple endocrine neoplasia type 1 (MEN 1). Moreover, pituitary lesions are affected by both protracted ectopic GHRH and loss of menin function. Of significance is the clarification of clinicopathological aspects of pGHRHomas in patients with or without MEN 1. From 1977-2016, thirty-six patients with pGHRHomas were reported. Twenty-two out of 36 patients (61%) had pGHRHomas with MEN 1 and 14 patients did not. The former had a tendency of male predominance, benign tumor behavior and fewer metastasis rather than the latter. The latter is a single pGHRHoma accompanied by pituitary enlargement with somatotroph hyperplasia (hyperplasia) caused by protracted ectopic GHRH. Nine patients with MEN 1 underwent transsphenoidal surgery (TSS). The hyperplasia associated with various pituitary adenomas (PAs) including three GH-related adenomas was observed in seven subjects (32%). In these patients, the resection of their pGHRHomas was feasible. Furthermore, all patients with acromegaly due to pGHRHomas without MEN 1 had non-TSS, whereas approximately 70% of those with MEN 1 had unnecessary TSS. The association with hyperplasia and various PAs suggested that formation of the three GH-related adenomas may be induced by the foundations of MEN 1 gene mutations. J. Med. Invest. 71 : 1-8, February, 2024.

[A rare case of intraductal tumor of the pancreas in which an intraductal tubulopapillary neoplasm was mixed with a widely spreading gastric-type intraductal papillary-mucinous neoplasm].

A 70-year-old man receiving treatment for diabetes mellitus presented with a cystic mass in the border area of the pancreatic body and tail on plain computed tomography (CT) due to impaired glucose intolerance. Contrast-enhanced CT showed a faint hyperattenuated nodular mass extending from the dilated main pancreatic duct (MPD) to the branch duct. Endoscopic retrograde cholangiopancreatography revealed a mildly dilated orifice of the papilla of Vater and MPD stenosis with entire upstream and immediate downstream dilatations. The patient underwent distal pancreatectomy due to the suspicion of mixed-type intraductal papillary-mucinous carcinoma. A pathological examination showed an intraductal solid-nodular mass measuring 25mm in length, consisting of two types of neoplasms. One showed tubulopapillary growth with entirely high-grade (HG) atypical cuboidal epithelium, in which immunohistochemical examinations were positive for MUC6 but negative for human gastric mucin (HGM), MUC1, MUC2, and MUC5AC, fitting the concept of intraductal tubulopapillary neoplasm (ITPN). The other showed the same growth of low-grade (LG) atypical columnar cells positive for HGM and MUC5AC and negative for MUC1 and MUC2, which corresponded to gastric-type intraductal papillary-mucinous neoplasm (IPMN) -LG. The tumor had not invaded the duct walls, and no metastatic lymph nodes were observed. The ITPN was adjacent to the IPMN mainly composed of tubular glands mimicking pyloric glands with LG dysplasia that corresponded to the so-called IPMN-pyloric gland variant. Moreover, the proliferation of low-papillary gastric-type IPMN spread around the intraductal tumors. Consequently, the patient was diagnosed with an intraductal tubular neoplasm comprising a noninvasive ITPN and gastric-type IPMN-LG. ITPN is a recently identified intraductal neoplasm of the pancreas proposed by Yamaguchi et al. and is distinguished by intraductal tubulopapillary growth with HG cellular atypia without overt mucin production, in contrast to IPMN. To date, no cases of intraductal nodular tumors comprising ITPN and IPMN have been reported. We report this original case with imaging and pathological observations and discuss potential processes via which ITPN and IPMN may arise adjacent to each other in the same pancreatic duct.

Exploiting the ferroaddiction of pancreatic cancer cells using Fe-doped nanoparticles.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with poor survival rates. Here, we evaluated iron-doped hydroxyapatite (FeHA) as a potential nanomedicine-based approach to combat PDAC. FeHA, in combination with a sublethal dose of the glutathione peroxidase 4 (GPX4) inhibitor RSL3, was found to trigger ferroptosis in KRAS mutant PANC-1 cells, but not in BxPC3 cells, while sparing normal human cells (fibroblasts and peripheral blood mononuclear cells). These findings were recapitulated in 3D spheroids generated using PDAC cells harboring wild-type versus mutant KRAS. Moreover, ferroptosis induction by FeHA plus RSL3 was reversed by the knockdown of STEAP3, a metalloreductase responsible for converting Fe3+ to Fe2+. Taken together, our data show that FeHA is capable of triggering cancer cell death in a KRAS-selective, STEAP3-dependent manner in PDAC cells.

Rutinosides-derived from Sarocladium strictum 6-O-α-rhamnosyl-ß-glucosidase show enhanced anti-tumoral activity in pancreatic cancer cells.

BACKGROUND: Low targeting efficacy and high toxicity continue to be challenges in Oncology. A promising strategy is the glycosylation of chemotherapeutic agents to improve their pharmacodynamics and anti-tumoral activity. Herein, we provide evidence of a novel approach using diglycosidases from fungi of the Hypocreales order to obtain novel rutinose-conjugates therapeutic agents with enhanced anti-tumoral capacity. RESULTS: Screening for diglycosidase activity in twenty-eight strains of the genetically related genera Acremonium and Sarocladium identified 6-O-α-rhamnosyl-ß-glucosidase (αRßG) of Sarocladium strictum DMic 093557 as candidate enzyme for our studies. Biochemically characterization shows that αRßG has the ability to transglycosylate bulky OH-acceptors, including bioactive compounds. Interestingly, rutinoside-derivatives of phloroglucinol (PR) resorcinol (RR) and 4-methylumbelliferone (4MUR) displayed higher growth inhibitory activity on pancreatic cancer cells than the respective aglycones without significant affecting normal pancreatic epithelial cells. PR exhibited the highest efficacy with an IC50 of 0.89 mM, followed by RR with an IC50 of 1.67 mM, and 4MUR with an IC50 of 2.4 mM, whereas the respective aglycones displayed higher IC50 values: 4.69 mM for phloroglucinol, 5.90 mM for resorcinol, and 4.8 mM for 4-methylumbelliferone. Further, glycoconjugates significantly sensitized pancreatic cancer cells to the standard of care chemotherapy agent gemcitabine. CONCLUSIONS: αRßG from S. strictum transglycosylate-based approach to synthesize rutinosides represents a suitable option to enhance the anti-proliferative effect of bioactive compounds. This finding opens up new possibilities for developing more effective therapies for pancreatic cancer and other solid malignancies.

Cytokine CCL9 Mediates Oncogenic KRAS-Induced Pancreatic Acinar-to-Ductal Metaplasia by Promoting Reactive Oxygen Species and Metalloproteinases.

Pancreatic ductal adenocarcinoma (PDAC) can originate from acinar-to-ductal metaplasia (ADM). Pancreatic acini harboring oncogenic Kras mutations are transdifferentiated to a duct-like phenotype that further progresses to become pancreatic intraepithelial neoplasia (PanIN) lesions, giving rise to PDAC. Although ADM formation is frequently observed in KrasG12D transgenic mouse models of PDAC, the exact mechanisms of how oncogenic KrasG12D regulates this process remain an enigma. Herein, we revealed a new downstream target of oncogenic Kras, cytokine CCL9, during ADM formation. Higher levels of CCL9 and its receptors, CCR1 and CCR3, were detected in ADM regions of the pancreas in p48cre:KrasG12D mice and human PDAC patients. Knockdown of CCL9 in KrasG12D-expressed pancreatic acini reduced KrasG12D-induced ADM in a 3D organoid culture system. Moreover, exogenously added recombinant CCL9 and overexpression of CCL9 in primary pancreatic acini induced pancreatic ADM. We also showed that, functioning as a downstream target of KrasG12D, CCL9 promoted pancreatic ADM through upregulation of the intracellular levels of reactive oxygen species (ROS) and metalloproteinases (MMPs), including MMP14, MMP3 and MMP2. Blockade of MMPs via its generic inhibitor GM6001 or knockdown of specific MMP such as MMP14 and MMP3 decreased CCL9-induced pancreatic ADM. In p48cre:KrasG12D transgenic mice, blockade of CCL9 through its specific neutralizing antibody attenuated pancreatic ADM structures and PanIN lesion formation. Furthermore, it also diminished infiltrating macrophages and expression of MMP14, MMP3 and MMP2 in the ADM areas. Altogether, our results provide novel mechanistic insight into how oncogenic Kras enhances pancreatic ADM through its new downstream target molecule, CCL9, to initiate PDAC.

Treatment strategies for borderline resectable pancreatic neuroendocrine tumors: a narrative review.

BACKGROUND AND OBJECTIVE: Well-differentiated pancreatic neuroendocrine tumors (pNETs) are a group of rare, heterogeneous tumors that originate in the endocrine tissue of the pancreas and account for 1-2% of all pancreatic neoplasms. The majority of pNETs are non-functional and typically follow a more indolent course. Especially at early stages, the primary management of pNETs is surgical resection which is associated with relatively low rates of recurrence and excellent long-term prognosis. On the other hand, some patients will present with locally advanced primary tumors or low volume metastatic disease in which complete surgical resection may be more difficult to achieve and recurrence rates are significant. Unlike treatment of borderline resectable (BR) pancreatic adenocarcinoma, in which neoadjuvant treatment strategies are becoming standardized, borderline resectability is not a currently established terminology for pNETs and the optimal multidisciplinary treatment approach is poorly understood. METHODS: We performed a literature search on PubMed, Google Scholar, and ClinicalTrials.gov using keywords, including 'pancreatic neuroendocrine tumor' and 'borderline resectable'. All studies and review articles in English with full text were considered. Each publication was independently reviewed. KEY CONTENT AND FINDINGS: We introduce the concept of BR-pNETs, focusing on important criteria that should be included in their definition by balancing the feasibility of resection and the clinical utility of surgery. We suggest that extended resection, involving vascular reconstruction, adjacent organ resection, and/or liver metastasis, should be considered at experienced, high volume centers. Furthermore, we outline multidisciplinary treatment strategies, including systemic and locoregional treatment options, for optimizing outcomes for this growing patient population. CONCLUSIONS: Formalizing the definition of resectability in pNETs through multidisciplinary collaborative research will be important for standardizing the indications for multimodality treatment and aggressive surgical approaches for patients.

A rare clinical case of extra-gastrointestinal stromal pancreatic tumor.

Extra-gastrointestinal stromal tumors arising from the pancreas are extremely rare. To date, just over 30 cases have been described in the world literature. A clinical observation of a 67-year-old patient with dull epigastric pain and a large cystic solid neoplasm instrumentally identified as an extra-gastrointestinal stromal tumor of the head of the pancreas is presented. The volume of surgical intervention consisted of pancreatogastroduodenectomy and right-sided hemicolectomy, since tumor invasion into the transverse mesocolon was detected intraoperatively. The final diagnosis of extra-gastrointestinal stromal sarcoma of the head of the pancreas with invasion into the mesocolon pT4N0M0, stage IIIb was made on the basis of histopathology and immunohistochemistry results.

Oil blotting paper for formalin fixation increases endoscopic ultrasound-guided tissue acquisition-collected sample volumes on glass slides.

OBJECTIVES: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is used for pathological diagnosis and obtaining samples for molecular testing, facilitating the initiation of targeted therapies in patients with pancreatic cancer. However, samples obtained via EUS-TA are often insufficient, requiring more efforts to improve sampling adequacy for molecular testing. Therefore, this study investigated the use of oil blotting paper for formalin fixation of samples obtained via EUS-TA. METHODS: This prospective study enrolled 42 patients who underwent EUS-TA for pancreatic cancer between September 2020 and February 2022 at the Osaka International Cancer Institute. After a portion of each sample obtained via EUS-TA was separated for routine histological evaluation, the residual samples were divided into filter paper and oil blotting paper groups for analysis. Accordingly, filter paper and oil blotting paper were used for the formalin fixation process. The total tissue, nuclear, and cytoplasm areas of each sample were quantitatively evaluated using virtual slides, and the specimen volume and histological diagnosis of each sample were evaluated by an expert pathologist. RESULTS: All cases were cytologically diagnosed as adenocarcinoma. The area ratios of the total tissue, nuclear, and cytoplasmic portions were significantly larger in the oil blotting paper group than in the filter paper group. The frequency of cases with large amount of tumor cells was significantly higher in the oil blotting paper group (33.3%) than in the filter paper group (11.9%) (p = 0.035). CONCLUSIONS: Oil blotting paper can increase the sample volume obtained via EUS-TA on glass slides and improve sampling adequacy for molecular testing.

Introduction of robotic pancreatoduodenectomy following phase 2a IDEAL guidelines.

BACKGROUND: Robotic pancreatoduodenectomy (RPD) is a newly introduced procedure, which is still evolving and lacks standardization. An objective assessment is essential to investigate the feasibility of RPD. The current study aimed to assess our initial ten cases of RPD based on IDEAL (Idea, Development, Exploration, Assessment, and Long-term study) guidelines. METHODS: This was a prospective phase 2a study following the IDEAL framework. Ten consecutive cases of RPD performed by two surgeons with expertise in open procedures at a single center were assigned to the study. With objective evaluation, each case was classified into four grades according to the achievements of the procedures. Errors observed in the previous case were used to inform the procedure in the next case. The surgical outcomes of the ten cases were reviewed. RESULTS: The median total operation time was 634 min (interquartile range [IQR], 594-668) with a median resection time of 363 min (IQR, 323-428) and reconstruction time of 123 min (IQR, 107-131). The achievement of the whole procedure was graded as A, "successful", in two patients. In two patients, reconstruction was performed with a mini-laparotomy due to extensive pneumoperitoneum, probably caused by insertion of a liver retractor from the xyphoid. Major postoperative complications occurred in two patients. One patient, in whom the jejunal limb was elevated through the Treitz ligament, had a bowel obstruction and needed to undergo re-laparotomy. CONCLUSIONS: RPD is feasible when performed by surgeons experienced in open procedures. Specific considerations are needed to safely introduce RPD.

Irreversible electroporation promotes a pro-inflammatory tumor microenvironment and anti-tumor immunity in a mouse pancreatic cancer model.

Pancreatic cancer is a significant cause of cancer-related mortality and often presents with limited treatment options. Pancreatic tumors are also notorious for their immunosuppressive microenvironment. Irreversible electroporation (IRE) is a non-thermal tumor ablation modality that employs high-voltage microsecond pulses to transiently permeabilize cell membranes, ultimately inducing cell death. However, the understanding of IRE's impact beyond the initiation of focal cell death in tumor tissue remains limited. In this study, we demonstrate that IRE triggers a unique mix of cell death pathways and orchestrates a shift in the local tumor microenvironment driven, in part, by reducing the myeloid-derived suppressor cell (MDSC) and regulatory T cell populations and increasing cytotoxic T lymphocytes and neutrophils. We further show that IRE drives induce cell cycle arrest at the G0/G1 phase in vitro and promote inflammatory cell death pathways consistent with pyroptosis and programmed necrosis in vivo. IRE-treated mice exhibited a substantial extension in progression-free survival. However, within a span of 14 days, the tumor immune cell populations reverted to their pre-treatment composition, which resulted in an attenuation of the systemic immune response targeting contralateral tumors and ultimately resulting in tumor regrowth. Mechanistically, we show that IRE augments IFN- Î³ signaling, resulting in the up-regulation of the PD-L1 checkpoint in pancreatic cancer cells. Together, these findings shed light on potential mechanisms of tumor regrowth following IRE treatment and offer insights into co-therapeutic targets to improve treatment strategies.

[Analysis of factors affecting the prognosis of patients with pancreatic cancer patients with obstructive jaundice].

Objective: Objective To analyze the relationship between the survival outcomes of pancreatic cancer patients with obstructive jaundice and various clinical and pathological factors. Methods: A case series study was conducted, where clinical data from pancreatic cancer patients with obstructive jaundice, who were admitted to the Cancer Hospital of Tianjin Medical University between March 2022 and May 2023, were retrospectively gathered. Factors potentially affecting patient prognosis were initially analyzed using univariate analysis, followed by multivariate analysis using the Cox regression model for selected factors. A P-value of less than 0.05 was deemed statistically significant. Results: The study included 104 patients, comprising 69 males and 35 females, with a median age of 62 years (ranging from 38 to 85 years). Of these, 76 patients (73.1%) were followed until death, with a median survival time of 8.9 (6.2,11.5) months. The number of deaths versus surviving cases at 6 and 12 months were 20/75 and 64/14, respectively, resulting in estimated survival rates of 79.6% and 22.8%. Univariate analysis identified factors such as weight loss, primary site, TNM stage, liver metastasis, number of organs with tumor, stage at which jaundice appeared, CA19-9 levels, albumin levels, and D-dimer levels as significant in influencing prognosis (all P<0.05). Multivariate analysis revealed TNM stage, number of organs with tumor, method of jaundice treatment, albumin levels, and D-dimer levels as independent prognostic factors (all P<0.05). Conclusion: In pancreatic cancer patients presenting with obstructive jaundice, close monitoring of weight loss, primary site, TNM stage, liver metastasis, number of organs with tumor, the timing of jaundice occurrence, method of jaundice treatment, CA19-9, albumin, and D-dimer levels is crucial, as these factors may significantly impact the patient's survival and prognosis.