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Transarterial chemoembolization (TACE) is performed for pancreatic neuroendocrine tumor (PanNEN) liver metastases; however, the safety and efficacy of TACE procedures, especially for patients who have undergone previous pancreatic surgery, have not been established. We reviewed 48 TACE procedures (1–6 procedures/patient) performed on 11 patients with PanNEN liver metastases, including 16 TACE procedures (4–6 procedures/patient) for 3 patients with a history of biliary-enteric anastomosis. The overall tumor objective response rate was 94%. The incidence of Clavien‒Dindo grade ≥ 2 complications was 1/16 (6%) and 1/32 (3%), and the median time to untreatable progression was 31 (14–41) and 27 (2–60) months among patients with and without a history of biliary-enteric anastomosis, respectively. Although validation is needed in future studies, our experiences have shown that TACE treatment is a viable treatment option for PanNEN liver metastases, even after biliary-enteric anastomosis with experienced teams and careful patient follow-up. [ABSTRACT FROM AUTHOR]

Background: Effects of pancreatectomy on glucose tolerance have not been clarified, and evidence regarding the difference in postoperative glucose tolerance between pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) is lacking.Study Design: This prospective, single-center observational study analyzed 40 patients undergoing PD and 29 patients undergoing DP (Clinical trial registry number UMIN000008122). Glucose tolerance, including insulin secretion (Δ C-peptide immunoreactivity, ΔCPR) and insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR) were assessed before and 1 month after pancreatectomy using the oral glucose tolerance test (OGTT) and glucagon stimulation test. We assessed long-term hemoglobin A1c (HbA1c) levels in patients, with a follow-up time of 3 years.Results: Percentages of patients diagnosed with abnormal OGTT decreased after PD (from 12 [30%] to 7 [17.5%] of 40 patients, p = 0.096); however, they increased after DP (from 4 [13.8%] to 8 [27.6%] of 29 patients, p = 0.103), although the changes were not statistically significant. ΔCPR decreased after both PD (from 3.2 to 1.0 ng/mL, p < 0.001) and DP (from 3.3 to 1.8 ng/mL, p < 0.001). HOMA-IR decreased after PD (from 1.10 to 0.68, p < 0.001), but did not change after DP (1.10 and 1.07, p = 0.42). Median HbA1c level was higher after DP than after PD for up to 3 years, but the differences were not statistically significant.Conclusions: In comparisons of pre- and 1 month post-pancreatectomy data, glucose tolerance showed improvement after PD, whereas it worsened after DP. Insulin secretion decreased after both PD and DP. Insulin resistance improved after PD, but did not change after DP. Further studies are warranted to clarify mechanisms of improved insulin resistance after PD. [ABSTRACT FROM AUTHOR]

Background: Recent evidence suggests that the presence of microbiome within human pancreatic ductal adenocarcinoma (PDAC) tissue potentially influences cancer progression and prognosis. However, the significance of tumor-resident microbiome remains unclear. We aimed to elucidate the impact of intratumoral bacteria on the pathophysiology and prognosis of human PDAC. Methods: The presence of intratumoral bacteria was assessed in 162 surgically resected PDACs using quantitative polymerase chain reaction (qPCR) and in situ hybridization (ISH) targeting 16S rRNA. The intratumoral microbiome was explored by 16S metagenome sequencing using DNA extracted from formalin-fixed paraffin-embedded tissues. The profile of intratumoral bacteria was compared with clinical information, pathological findings including tumor-infiltrating T cells, tumor-associated macrophage, fibrosis, and alterations in four main driver genes (KRAS, TP53, CDKN2A/p16, SMAD4) in tumor genomes. Results: The presence of intratumoral bacteria was confirmed in 52 tumors (32%) using both qPCR and ISH. The 16S metagenome sequencing revealed characteristic bacterial profiles within these tumors, including phyla such as Proteobacteria and Firmicutes. Comparison of bacterial profiles between cases with good and poor prognosis revealed a significant positive correlation between a shorter survival time and the presence of anaerobic bacteria such as Bacteroides, Lactobacillus, and Peptoniphilus. The abundance of these bacteria was correlated with a decrease in the number of tumor-infiltrating T cells positive for CD4, CD8, and CD45RO. Conclusions: Intratumoral infection of anaerobic bacteria such as Bacteroides, Lactobacillus, and Peptoniphilus is correlated with the suppressed anti-PDAC immunity and poor prognosis. [ABSTRACT FROM AUTHOR]

Background: Abundant collagen deposition is a hallmark of pancreatic ductal adenocarcinomas (PDACs). This study clarified the interactive relationship between tumor-stromal collagen, molecular and immune characteristics, and tumor pr ogression in human PDAC. Methods: We performed a comprehensive examination using an integrative molecular pathological epidemiology database on 169 cases with resected PDAC. The amount of tumor-stromal collagen was quantified through digital imaging analysis for Elastica van Gieson-stained whole-section tumor slides. We analyzed the association of tumor-stromal collagen with gene alterations (KRAS, TP53, CDKN2A/p16, and SMAD4), immune parameters (CD4+ tumor-infiltrating lymphocytes [TILs], CD8+ TILs, FOXP3+ TILs, and tertiary lymphoid structures), and patient prognosis. Results: Low amounts of tumor-stromal collagen were associated with poor differentiation (multivariable OR = 3.82, 95%CI = 1.41–12.2, P = 0.008) and CDKN2A/p16 alteration (OR [95%CI] = 2.06 [1.08–4.02], P = 0.03). Tumors with low collagen levels had shorter overall survival (HR [95%CI] = 2.38 [1.59–3.56], P < 0.0001). In the S-1 and gemcitabine (GEM) treatment groups, low tumor-stromal collagen was linked to poor prognosis of patients with PDAC (S-1 group: multivariable HR [95%CI] = 2.76 [1.36–5.79], P = 0.005; GEM group: multivariate HR [95%CI] = 2.91 [1.34–6.71], P = 0.007). Additionally, low amounts of tumor-stromal collagen were also linked to low levels of CD4+ TILs (P = 0.046), CD8+ TILs (P = 0.09), and tertiary lymphoid structures (P = 0.001). Conclusions: Tumor-stromal collagen deposition may play a crucial role in modulating tumor-immune microenvironment and determining response to adjuvant chemotherapy and patient survival outcomes. [ABSTRACT FROM AUTHOR]

Background and Aim: Endoscopic ultrasonography (EUS) findings of the pancreatic parenchyma, such as hyperechoic foci/stranding and lobularity, may be associated with the severity of chronic pancreatitis (CP). However, the correlation between parenchymal EUS findings and histology remains unclear. We designed a large‐scale retrospective study analyzing over 200 surgical specimens to elucidate the association between parenchymal EUS findings and histological features. Methods: Clinical data of 221 patients with pancreatobiliary tumors who underwent preoperative EUS and pancreatic surgery between January 2010 and November 2020 were reviewed to investigate the association between parenchymal EUS findings and histological features at the pancreatic body. None of these patients met the definition of CP. Results: Of the 221 patients, 87 (39.4%), 89 (40.2%), and 45 (20.4%) had normal EUS findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity, respectively. In the multivariate analyses, parenchymal EUS findings significantly correlated with histological CP findings of fibrosis, inflammation, and atrophy (hyperechoic foci/stranding without lobularity vs hyperechoic foci/stranding with lobularity, odds ratio [95% confidence interval]: 4.1 [2.2–7.9] vs 31.3 [9.3–105.6], Ptrend < 0.001; 3.9 [1.9–8.2] vs 21.8 [8.0–59.4], Ptrend < 0.001; and 4.0 [2.0–7.8] vs 22.9 [7.0–74.5], Ptrend < 0.001, respectively). Further, a trend toward higher histological grade was observed in the following order: normal findings, hyperechoic foci/stranding without lobularity, and hyperechoic foci/stranding with lobularity. Conclusions: Endoscopic ultrasonography findings of the pancreatic parenchyma may be associated with the histological conditions in CP, such as pancreatic fibrosis, inflammation, and atrophy. Lobularity reflects more severe histological conditions than does hyperechoic foci/stranding. [ABSTRACT FROM AUTHOR]

Background: Factors associated with long-term survival in gemcitabine-concurrent proton radiotherapy (GPT) for non-metastatic, locally advanced pancreatic cancer (LAPC) remain unclear. This study aimed to determine the factors associated with long-term survival in GPT for non-metastatic LAPC.Methods: The medical records of 123 patients with LAPC treated with GPT between February 2009 and December 2019 at Hyogo Ion Beam Medical Center were retrospectively reviewed to assess the factors associated with long-term survival outcomes.Results: The median overall survival of the total cohort treated with GPT was 18.7 months. The 1- and 2-year overall, local progression-free, and progression-free survival rates were 70.4% and 35.7%, 78.2% and 59.0%, and 38.6% and 20.8%, respectively. Multivariate analysis revealed that LAPCs at the pancreatic body-tail and those without anterior peripancreatic invasion were independently associated with longer overall survival (P = 0.040 and P = 0.015, respectively). The median overall survival of patients with LAPC at the pancreatic body-tail and those with LAPC without anterior peripancreatic invasion were 24.1 and 28.1 months, respectively. LAPCs at the pancreatic body-tail had a higher volume ratio irradiated over 60 Gy equivalents at gross tumor volume than those at the pancreatic head (P < 0.001). LAPCs with anterior peripancreatic invasion had more peritoneal recurrence within 6 months after GTP than those without anterior peripancreatic invasion (P = 0.039).Conclusions: GPT is a promising treatment option for patients with LAPC at the pancreatic body-tail and those with LAPC without anterior peripancreatic invasion. [ABSTRACT FROM AUTHOR]

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a distinct entity characterized by papillary proliferations of mucin-producing epithelial cells with excessive mucin production and cystic dilatation of the pancreatic ducts. The clinical presentation often involves recurrent episodes of pancreatitis associated with the temporal obstruction of the main pancreatic duct caused by the hypersecretion of mucin. We herein describe a case in which the patient repeatedly experienced the occurrence of idiopathic acute pancreatitis in the head of the pancreas over a 9-year period, and who was ultimately was cured by distal pancreatectomy for IPMNs in the pancreatic tail. This case illustrates the potential pitfalls in the diagnosis of IPMNs owing to a discrepancy between the site of pancreatitis and that of the IPMN. The possible mechanisms linking acute pancreatitis with the formation of IPMNs are also reviewed. [ABSTRACT FROM AUTHOR]

Background: Particle radiotherapy has increasingly gained acceptance for locally advanced pancreatic cancers owing to superior tumor conformity and dosimetry compared to conventional photon radiotherapy. However, the close proximity of the pancreas to the stomach and duodenum leads to radiation-induced gastrointestinal toxicities, which hinder the delivery of curative doses to the tumor. To overcome this problem, a surgical spacer was placed between the tumor and gastrointestinal tract, and subsequent proton radiotherapy was performed in this study.Methods: Data from 9 patients who underwent surgical spacer placement and subsequent proton radiotherapy were analyzed. The safety and feasibility of the spacer placement surgery were evaluated; the impact of the spacer on dosimetry was also assessed using dose volume histogram (DVH) analyses, before and after surgical spacer placement.Results: Surgical spacer placement and subsequent proton radiotherapy were successfully completed in all cases. Surgical spacer placement significantly improved the dose intensity covering 95%, mean, and minimum doses for the gross tumor volume, and the clinical and planning target volume based on the DVH, while respecting the dose constraints of the gastrointestinal tract. Based on the Common Terminology Criteria for Adverse Events, two patients (22.2%) developed gastrointestinal ulcer (Grade 2) at 1 and 35 months, and one patient (11.1%) developed gastric perforation (Grade 4) at 4 months after proton radiotherapy.Conclusions: Surgical spacer placement in the locally advanced pancreatic body and tail cancers is relatively safe and technically feasible. Comparing radiation plans, surgical spacer placement seems to improve the dose distribution in the locally advanced pancreatic body and tail cancers, which are close to the gastrointestinal tract. [ABSTRACT FROM AUTHOR]

Background/Objectives: The recent guideline for intraductal papillary mucinous neoplasms (IPMNs) focuses on morphological features of the lesion as signs of malignant transformation, but ignores the background pancreatic parenchyma, including features of chronic pancreatitis (CP), which is a risk factor for pancreatic malignancies. Endoscopic ultrasonography frequently reveals evidence of CP (EUS-CP findings) in the background pancreatic parenchyma of patients with IPMNs. Therefore, we investigated whether background EUS-CP findings were associated with malignant IPMN. Methods: The clinical data of 69 consecutive patients with IPMNs who underwent preoperative EUS and surgical resection between April 2010 and October 2014 were collected prospectively. The association of EUS-CP findings (total number of EUS-CP findings; 0 vs. ≥ 1) with invasive IPMN was examined. The association of EUS-CP findings with pathological changes of the background pancreatic parenchyma (atrophy/inflammation/fibrosis) was also examined. Results: Among patients with EUS-CP findings, invasive intraductal papillary mucinous carcinoma (IPMC) was significantly more frequent than among patients without EUS-CP findings (42.5% [17/40] vs. 3.4% [1/29], p = 0.0002). In addition, patients with EUS-CP findings had higher grades of pancreatic atrophy and inflammation than patients without EUS-CP findings (atrophy: 72.5% [29/40] vs. 34.5% [10/29], p = 0.003; inflammation: 45.0% [18/40] vs. 20.7% [6/29], p = 0.04). Conclusions: In IPMN patients, detection of EUS-CP findings in the background pancreatic parenchyma was associated with a higher prevalence of invasive IPMC. Accordingly, EUS examination should not only assess the morphological features of the lesion itself, but also EUS-CP findings in the background parenchyma. [ABSTRACT FROM AUTHOR]

Hemosuccus pancreaticus (HP) is mostly induced by a ruptured pseudoaneurysm or hemorrhage from a pseudocyst in chronic pancreatitis. We herein report a rare case with HP induced by tumor hemorrhage. The present patient is a 71-year-old woman referred to us with a diagnosis of severe progressive anemia. Endoscopy revealed hemorrhage from the papilla of Vater. Computed tomography showed a multilocular cystic tumor in the tail of the pancreas. The patient underwent a distal pancreatectomy. The histopathological diagnosis was carcinoma in mucinous cystadenoma. No cancer infiltration into the pancreatic duct was detected. Pancreatography of the resected specimen demonstrated an overt communication between the main pancreatic duct and the cystic cavity of the tumor, which was not demonstrated preoperatively by endoscopic retrograde pancreatography. Although the cause of HP is mainly acute or chronic pancreatitis, we should bear in mind that a pancreatic tumor may be a possible cause of HP and that, as such, prompt and proper treatment is mandatory. [ABSTRACT FROM AUTHOR]

Background: Borderline resectable pancreatic cancer (BRPC) is frequently associated with positive surgical margins and a poor prognosis because the tumor is in contact with major vessels. This study evaluated the relationship between the margin-negative (R0) resection rate and findings indicating peripancreatic vascular invasion on multidetector computed tomography (MDCT) imaging after neoadjuvant chemoradiotherapy (NACRT) in patients with BRPC.Methods: Twenty-nine BRPC patients who underwent laparotomy after neoadjuvant S-1 with concurrent radiotherapy were studied retrospectively. Peripancreatic major vessel invasion was evaluated based on the length of tumor-vessel contact on MDCT. The R0 resection rates were compared between the progression of vascular invasion (PVI) group and the non-progression of vascular invasion (NVI) group.Results: There were 3 patients with partial responses (10%), 25 with stable disease (86%), and 1 with progressive disease (3%) according to the RECISTv1.1 criteria. Regarding vascular invasion, 9 patients (31%) were classified as having PVI, and 20 patients (69%) were classified as having NVI. Of the 29 patients, 27 (93%) received an R0 resection, and all the PVI patients received an R0 resection (9/9; R0 resection rate = 100%) while 90% (18/20) of the NVI patients underwent an R0 resection. The exact 95% confidence interval of risk difference between those R0 resection rates was - 10.0% [- 31.7-20.4%].Conclusions: Patients with BRPC after NACRT achieved high R0 resection rates regardless of the vascular invasion status. BRPC patients can undergo R0 resections unless progressive disease is observed after NACRT.Trial Registration: UMIN-CTR, UMIN000009172 . Registered 23 October 2012. [ABSTRACT FROM AUTHOR]