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Accurately identifying neoantigens is crucial for developing effective cancer vaccines and improving tumor immunotherapy. Mass spectrometry-based immunopeptidomics has emerged as a promising approach to identifying human leukocyte antigen (HLA) peptides presented on the surface of cancer cells, but false-positive identifications remain a significant challenge. In this study, liquid chromatography-tandem mass spectrometry-based proteomics and next-generation sequencing were utilized to identify HLA-presenting neoantigenic peptides resulting from non-synonymous single nucleotide variations in tumor tissues from 18 patients with renal cell carcinoma or pancreatic cancer. Machine learning was utilized to evaluate Mascot identifications through the prediction of MS/MS spectral consistency, and four descriptors for each candidate sequence: the max Mascot ion score, predicted HLA binding affinity, aliphatic index and retention time deviation, were selected as important features in filtering out identifications with inadequate fragmentation consistency. This suggests that incorporating rescoring filters based on peptide physicochemical characteristics could enhance the identification rate of MS-based immunopeptidomics compared to the traditional Mascot approach predominantly used for proteomics, indicating the potential for optimizing neoantigen identification pipelines as well as clinical applications.

Abstract Purpose Reports on the association of perioperative nutritional and inflammatory status with the clinical course of adjuvant chemotherapy did not include neoadjuvant chemotherapy. We aimed to clarify the mechanism by which perioperative nutritional and inflammatory status affect the clinical course of postoperative adjuvant chemotherapy in patients with pancreatic cancer. Methods We enrolled 123 patients with pancreatic cancer retrospectively who underwent surgical resection with neoadjuvant and S-1 adjuvant chemotherapy between January 2013 and December 2022. The duration of continuing S-1 treatment and the continuation rates at 3 and 6 months after initiating adjuvant chemotherapy were calculated using the Kaplan–Meier method. The log-rank test was used to evaluate statistical differences between the high and low prognostic nutritional index (PNI) groups. Univariable and multivariable analyses were performed to determine the risk factors for continuing S-1 adjuvant chemotherapy. Results The optimal cut-off value for preoperative PNI was 45. Preoperative PNI was an independent risk factor for continuing S-1 adjuvant chemotherapy in patients who underwent perioperative adjuvant chemotherapy and surgical resection (hazard ratio = 2.435, 95% confidence interval = 1.229 − 4.824, p = 0.011). Low PNI was associated with lower S-1completion (p = 0.02) and higher S-1 withdrawal (p = 0.031). Additionally, the preoperative PNI status affected ≥ grade 2 adverse events caused by adjuvant chemotherapy (p

Abstract Background Intraductal oncocytic papillary neoplasm (IOPN), previously classified as a subtype of intraductal papillary mucinous neoplasm (IPMN), has been described as an independent disease by the WHO since 2019. IOPN is a rare tumor, with few reported cases. Herein, we report a case of resected non-invasive IOPN that formed a lesion protruding toward the duodenum from the accessory papilla. Case presentation An 80-year-old woman was referred to our hospital because of a giant mass in the pancreatic head detected on abdominal contrast-enhanced computed tomography (CT) performed for a close examination of a mass in the right breast. CT revealed a 90-mm-sized tumor with a mixture of solid and cystic components, with contrast enhancement in the pancreatic head, and a dilated main pancreatic duct. Esophagogastroduodenoscopy revealed a semi-circumferential papillary tumor protruding toward the duodenal lumen, which did not protrude from the papilla of Vater. Transpapillary biopsy led to a preoperative diagnosis of IPMN with an associated invasive carcinoma. As there were no distant metastasis, open subtotal stomach-preserving pancreaticoduodenectomy was performed. Analysis of the surgical specimen and histopathological examination revealed that the tumor was an IOPN that protruded toward the duodenal mucosa from the accessory papilla while replacing the duodenal mucosa with no obvious stromal invasion. Conclusion IOPN is a rare and poorly recognized tumor with few reported cases. There have been no reports describing IOPN forming a protruding lesion toward the duodenum from the accessory papilla. Therefore, further accumulation of cases such as this one is important to advance the study of IOPN.

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, and surgical resection is the only potentially curative approach. However, the rate of recurrence remains high, particularly within the first 6 months, and is associated with a poor prognosis. The present study evaluated the clinical characteristics and risk factors for early recurrence in pancreatic ductal adenocarcinoma (PDAC) patients who underwent curative resection, regardless of the use of neoadjuvant chemotherapy, to identify predictive factors associated with early recurrence and poor outcomes as well as to determine the optimal treatment strategy for patients at high risk of early recurrence after surgical resection. Methods Patients who underwent pancreatic resection for PDAC at our institution from 2013 to 2021 were included in this study. We investigated the clinicopathological features of patients in groups: those with recurrence within 6 months, recurrence between 6 and 12 months, and recurrence beyond 12 months or no recurrence. A logistic regression analysis identified covariates associated with early recurrence at 6 and 12 months. Results The study included 403 patients with a median follow-up of 25.7 months. Recurrence was observed in 279 patients, with 14.6% recurring within 6 months, 23.3% within 6–12 months, and 62% after 12 months or not at all. The preoperative CA19-9 level, modified Glasgow prognostic score (mGPS), and positive peritoneal cytology were significant risk factors for early recurrence within 6 months, while positive peritoneal cytology, lymph node metastasis, and the absence of adjuvant chemotherapy were significant risk factors for recurrence within 12 months. For patients who received preoperative chemotherapy or chemoradiotherapy, the preoperative CA19-9 level, mGPS, and positive peritoneal cytology were significant independent risk factors for early recurrence within 6 months, while positive peritoneal cytology, lymph node metastasis, and the absence of adjuvant chemotherapy were significant independent risk factors for recurrence within 12 months. The study concluded that the overall survival after surgical resection for potentially resectable PDAC worsened according to the number of risk factors present in the patient. Conclusions We clarified that preoperative CA19-9, positive peritoneal cytology, and the lack of adjuvant chemotherapy were consistent predictors for early recurrence within 6 and 12 months. In addition, an increased number of risk factors affecting the patient was associated with a poorer overall survival after potentially curable resection. Calculating the number of risk factors for early recurrence may be an essential predictive factor when considering treatment strategies.

Summary: The aggressiveness of pancreatic ductal adenocarcinoma (PDAC) is affected by the tumor microenvironment (TME). In this study, to recapitulate the PDAC TME ex vivo, we cocultured patient-derived PDAC cells with mesenchymal and vascular endothelial cells derived from human induced pluripotent stem cells (hiPSCs) to create a fused pancreatic cancer organoid (FPCO) in an air-liquid interface. FPCOs were further induced to resemble two distinct aspects of PDAC tissue. Quiescent FPCOs were drug resistant, likely because the TME consisted of abundant extracellular matrix proteins that were secreted from the various types of cancer-associated fibroblasts (CAFs) derived from hiPSCs. Proliferative FPCOs could re-proliferate after anticancer drug treatment, suggesting that this type of FPCO would be useful for studying PDAC recurrence. Thus, we generated PDAC organoids that recapitulate the heterogeneity of PDAC tissue and are a potential platform for screening anticancer drugs.

We present the case of a 35-year-old man with intractable nausea, vomiting, and severe anemia. A computed tomography (CT) scan of the chest, abdomen, and pelvis showed a circumferential lesion thickening of up to 3.5 cm at the level of the third portion of the duodenum. No aortocaval, retroperitoneal lymphadenopathy, nor secondary lesion was observed. Esophagogastroduodenoscopy (EGD) revealed a circumferential mass within the third portion of the duodenum. Histopathology of biopsy materials from the duodenal mass showed it most likely to be a poorly differentiated adenocarcinoma. The patient underwent a subtotal stomach-preserving pancreaticoduodenectomy with regional lymph node dissection. Histologically, tumor cells with basophilic cytoplasm and pleomorphic nuclei showed a solid pattern, and expressed CD30 and SALL4 immunohistochemically, leading to a diagnosis of embryonal carcinoma-like tumor. No other primary tumor could be identified, and the location of the tumor, mainly on the mucosal surface, suggested a duodenal origin. The UICC TNM staging was T3N2M0, stage IIB. This is a rare case of primary duodenal carcinoma with features of embryonal carcinoma.

Abstract Background Expression of human equilibrative nucleoside transporter‐1 (hENT1) is reported to predict survival of gemcitabine (GEM)‐treated patients. However, predictive values of immunohistochemical hENT1 expression may differ according to the antibodies, 10D7G2 and SP120. Aim We aimed to investigate the concordance of immunohistochemical hENT1 expression between the two antibodies and prognosis. Methods The subjects of this study were totally 332 whose formalin‐fixed paraffin‐embedded specimens and/or unstained sections were obtained. The individual H‐scores and four classifications according to the staining intensity were applied for the evaluation of hENT1 expression by 10D7G2 and SP120, respectively. Results The highest concordance rate (79.8%) was obtained when the cut‐off between high and low hENT1 expression using SP120 was set between moderate and strong. There were no correlations of hENT1 mRNA level with H‐score (p = .258). Although the hENT1 mRNA level was significantly different among four classifications using SP120 (p = .011), there was no linear relationship among them. Multivariate analyses showed that adjuvant GEM was a significant predictor of the patients with low hENT1 expression using either 10D7G2 (Hazard ratio [HR] 2.39, p = .001) or SP120 (HR 1.84, p

Abstract 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 Background Neuroendocrine carcinoma (NEC) originating from the extrahepatic bile duct (EHBD) is very rare but is known for its aggressiveness and poor prognosis. We herein report a case of rapidly progressed NEC in the extrahepatic bile duct. Case presentation An 84-year-old man was referred to our facility with obstructive jaundice and abdominal pain. Imaging studies revealed an irregular filling defect in the middle bile duct by endoscopic retrograde cholangiopancreatography and an enhanced wall thickening from the middle to distal portion by enhanced computed tomography. The patient was initially diagnosed with extrahepatic cholangiocarcinoma by a bile duct biopsy and underwent pancreatoduodenectomy with lymph node dissection. The pathological findings showed an NEC with an adenosquamous carcinoma component in the extrahepatic bile duct with lymph node metastases. The patient experienced multiple liver metastases 1 month after surgery and died 3 months after surgery. Due to the rapid progression of his disease, his general condition deteriorated, and he was unable to receive any additional treatments, such as chemotherapy. Conclusion As shown in our case, NEC of the EHBD has an extremely poor prognosis and can sometimes progress rapidly. Multimodality treatment should be considered, even in cases of locoregional disease.

Abstract Background Cancer cells are often found postoperatively at surgical resection margins (RM) in patients with gastric cancer because of submucosal infiltration or hesitation to secure adequate RM. This study was designed to evaluate risk factors for microscopic positive RM and to clarify which patients should undergo intraoperative frozen section diagnosis (IFSD). Methods Patients who underwent R0/1 gastrectomy for gastric adenocarcinoma between 2000 and 2018 in a single cancer center in Japan were studied. We divided the patients into a positive RM group and negative RM group according to the results of definitive histopathological examinations. We performed multivariate analysis to analyze risk factors for positive RM by and used the identified risk factors to risk stratify the patients. Results A total of 2757 patients were studied, including 49 (1.8%) in the positive RM group. The risk factors significantly associated with positive RM were remnant gastric cancer (odds ratio [OR] 4.7), esophageal invasion (OR 6.3), tumor size ≥80 mm (OR 3.9), and a histopathological diagnosis of undifferentiated type (OR 3.6), macroscopic type 4 (OR 3.7), or pT4 disease (OR 4.6). On risk stratification analysis, the incidence of positive RM was 0.1% without any risk factors, increasing to 0.4% with one risk factor, 3.1% with two risk factors, 5.3% with three risk factors, 21.3% with four risk factors, and 85.7% with five risk factors. Conclusions The risk of macroscopically positive RM increased in patients who have risk factors. IFSD should be performed in patients who have four or more risk factors.

Background: Routine therapy of metabolic bone disorder (MBD) after gastrectomy for gastric cancer has not been established yet. We have reported that administering an active vitamin D3 agent to patients who had undergone gastrectomy for gastric cancer improved MBD. Recently, the usefulness of alendronate, an osteoclast inhibitor, has been reported for MBD. Here we report the effects of alendronate for MBD after gastrectomy for gastric cancer. Methods: Dual energy X-ray absorptiometry was performed consequently in 14 patients, who had been gastrectomized for gastric cancer and survived more than 5 years without recurrence, to evaluate the MBD and compared before and after treatment. The 14 patients were divided into two groups: in group VD3, 1 μg/d of alfacalcidol, an active vitamin D3 agent, was administered; and in group ALN, 5 mg/d or 35 mg/wk of alendronate or both alfacalcidol and alendronate were administered. These drugs had been administered to the patients for > 2 years, and the patients were followed up. Results: After 12 months, dual energy X-ray absorptiometry revealed that bone mineral density and T score were significantly increased in group ALN. Changes in serum bone-specific alkaline phosphatase after 24 months were −9.1 μg/L in the ALN group and 3.75 μg/L in the VD3 group, showing a significant difference (p = 0.02). No serious adverse events were observed in either group. Conclusion: These results showed the usefulness of alendronate and alendronate+activated vitamin D3 combination therapy, suggesting that these treatments might prevent postgastrectomic MBD.

Adenomyomatous hyperplasia is rarely found in the extrahepatic bile duct. A 54-year-old man was referred to our center with a diagnosis of extrahepatic bile duct stenosis which had been detected by endoscopic retrograde choloangiopancreatography. Abdominal computed tomography revealed thickening of the wall of the middle extrahepatic bile duct, however no malignant cells were detected by cytology. Since bile duct carcinoma could not be ruled out, we performed resection of the extrahepatic duct accompanied by lymph node dissection. Histopathologically, the lesion was diagnosed as adenomyomatous hyperplasia of the extrahepatic bile duct. Present and previously reported cases showed the difficulty of making a diagnosis of adenomyomatous hyperplasia of the extrahepatic bile duct preoperatively or intraoperatively. Therefore, when adenomyomatous hyperplasia is suspected, a radical surgical procedure according to malignant disease may be necessary for definitive diagnosis.

Metastatic lesions in the liver derived from colorectal cancer rarely invade the portal vein macroscopically. Portal vein tumor thrombus is commonly associated with hepatocellular carcinoma. Colorectal liver metastases are usually accompanied by microscopic tumor invasion into the intrahepatic portal vein, and the incidence of macroscopic tumor thrombus in the trunk of the portal vein is rare. Here, we provide unique appearance of metastatic colorectal cancer. To the best of our knowledge, macroscopically, the right portal vein filled with the tumor thrombus without any tumor in liver parenchyma has been quite rare.