Pancreatic Specimens Research Articles

A case of needle tract seeding of pancreatic adenosquamous carcinoma after a single endoscopic ultrasound-guided tissue acquisition.

Needle tract seeding (NTS) is a rare complication of endoscopic ultrasound-guided tissue acquisition (EUS-TA). Herein, we report the case of an 83year-old man who presented with a solid mass in the pancreatic tail, measuring 35mm in diameter, with cystic degeneration. EUS-TA was performed using a 22-gauge biopsy needle, with a single puncture via the stomach; however, no definitive pathological diagnosis was achieved. Due to the strong suspicion of malignancy, surgery was performed at the patient's request, and the postoperative pathological diagnosis was pancreatic adenosquamous carcinoma. One year after surgery, computed tomography revealed a string of bead-like nodules within the gastric wall. Esophagogastroduodenoscopy revealed three submucosal, tumor-like raised lesions aligned in a row on the upper posterior wall of the gastric body. EUS detected a solid mass with cystic degeneration. Histological findings from EUS-TA specimens were consistent with those from the pancreatic resection specimen, leading to a diagnosis of NTS. Although reports of NTS have been increasing in recent years, cases of NTS occurring after only a single puncture remain extremely rare. This case clearly demonstrates that NTS can occur even after a single puncture, highlighting the importance of obtaining thorough informed consent regarding this risk prior to performing EUS-TA.

Effect of warm and cold ischemia on pancreaticoduodenectomy specimen following robotic pancreaticoduodenectomy

BackgroundThe adoption of robotic pancreaticoduodenectomy (PD) has increased in recent years for the treatment of pancreatic head tumors and periampullary lesions. Some potential benefits seem to be demonstrated; however, obtaining specimens through this method can potentially compromise the diagnosis depending on the timing of the specimen retrieval, and the impact of longer perioperative time on ischemia and autolysis of the surgical specimen has not been analyzed. The aim of this study is to evaluate the histological changes associated with timing of specimen retrieval during robotic PD.MethodsA review of histopathology files was performed for all pancreatic specimens collected at our hospital from January 2022 to March 2024. Both warm ischemia time (WIT) and cold ischemia time (CIT) were collected. Histological features related to ischemic damage were evaluated in normal duodenal and pancreatic parenchyma as well as pancreatic tumor, and were graded as: absent, mild, moderate and severe. Univariate and multivariate analyses were performed to determine which variables were associated with moderate and severe ischemic changes.ResultsSixty surgical specimens were analyzed: 20 open PD, 17 robotic PD with cold ischemia, and 23 robotic PD. Median total WIT was 182 min (open PD 57 min vs. RPD 190 min vs. RPD-CI 198 min; p < 0.001). Median CIT was 760 min (740–835) in samples stored at 4ºC. Univariate analysis showed that longer intraoperative time, male gender and cold ischemia were associated with pancreatic tissue ischemic changes. In multivariate analysis, cold ischemia was the only independent factor associated with normal pancreatic tissue and tumor tissue moderate and severe ischemic changes.ConclusionsProlonged ischemia time, especially in the case of cold storage, has a strong effect on the degradation of normal and tumor tissue without affecting pathological evaluation. Operative teams should aim to optimize both the duration and efficiency of the surgical procedure, ensuring minimal ischemic time. Simultaneously, pathology departments must be equipped to process pancreatic specimens promptly, with protocols in place to minimize the time between resection and analysis.

Abstract C076: Transcriptomic analyses of normal human pancreatic acinar cells reveal the presence of cancer subtypes that correlate with acinar ductal metaplasia

Abstract Gene expression subtypes exist in pancreatic ductal adenocarcinoma (PDAC), however comparable subtypes are not known to exist in normal human pancreas. Our laboratory has collected a large (N=55) and racially diverse (14 Black, 27 White and 14 Hispanic) cohort of normal human pancreatic acinar cell specimens that were processed at islet transplantation centers. Deceased organ donors were maintained on life support until the time the pancreas was surgically removed. Samples of primary, uncultured (Day 0) or ADM transdifferentiated (Day 6) normal pancreatic acinar cells were subjected to bulk transcriptomic sequencing. UMAP analysis of the transcriptomic data from the Day 0 samples revealed the presence of two distinguishable clusters of data that we arbitrarily refer to as Group 1 (n = 31) and Group 2 (n = 24). Heatmaps of the expression of 57 genes belonging to the exocrine-like, classical and basal subtypes produced a clear separation of the data. Since the exocrine-like genes increased in Group 1 and the basal and classical genes increased in Group 2, we refer to Group 1 as the exocrine-like subtype and Group 2 as the basal/classical subtype. The basal/classical subtype samples showed greater morphological and molecular acinar ductal metaplasia compared to those in the exocrine-like subtype. When stratified by demographics and subtype, volcano plots revealed a striking trend with Blacks, women, obese and younger individuals having significantly fewer differentially expressed genes (basal/classical vs exocrine-like) compared to Hispanics, men, nonobese and older individuals. Our data demonstrate that, similar to PDAC, normal pancreatic acinar cells are distinguishable by gene subtypes. Moreover, the gene expression ratio of these subtypes varies dramatically by donor demographics. Citation Format: Corey M Perkins, Jinmai Jiang, Zachary Greenberg, Md Abu Talha Siddique, Linda C Williams, Jason O Brant, Kalyanne Shirlekar, Bo Han, Jamel Ali, Kristianna M Fredenburg, Kiley Graim, Diana J Wilkie, Mei He, Thomas D Schmittgen. Transcriptomic analyses of normal human pancreatic acinar cells reveal the presence of cancer subtypes that correlate with acinar ductal metaplasia [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr C076.

TAK1 Promotes an Immunosuppressive Tumor Microenvironment through Cancer-Associated Fibroblast Phenotypic Conversion in Pancreatic Ductal Adenocarcinoma.

We aim to clarify the precise function of TGFβ1-activated kinase 1 (TAK1) in cancer-associated fibroblasts (CAF) within human pancreatic ductal adenocarcinoma (PDAC) by investigating its role in cytokine-mediated signaling pathways. The expression of TAK1 in pancreatic cancer was confirmed by The Cancer Genome Atlas data and human pancreatic cancer specimens. CAFs from freshly resected PDAC specimens were cultured and used in a three-dimensional model for direct and indirect coculture with PDAC tumors to investigate TAK1 function. Additionally, organoids from [LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre (KPC)] mice were mixed with CAFs and injected subcutaneously into C57BL/6 mice to explore in vivo functional interactions of TAK1. The Cancer Genome Atlas data revealed significant upregulation of TAK1 in PDAC, associating with a positive correlation with the T-cell exhaustion signature. Knockdown of TAK1 in CAFs decreased the inflammatory CAF signature and increased the myofibroblastic CAF signature both in vitro and in vivo. The absence of TAK1 hindered CAF proliferation, blocked several inflammatory factors via multiple pathways associated with immunosuppression, and hindered epithelial-mesenchymal transition and outgrowth in vitro in spheroid cocultures with PDAC cells. Additionally, TAK1 inhibitor restrained tumor growth, increased CD4+ and CD8+ T-cell abundance, and reduced immunosuppressive cells present in vivo. Blocking the TAK1+ CAF phenotype leads to the conversion of protumorigenic CAFs to antitumorigenic CAFs. This highlights TAK1 as a potential therapeutic target, particularly in CAFs, and represents a novel avenue for combined immunotherapy in PDAC.

Cadmium-induced pancreatic toxicity in rats: comparing vitamin C and Nigella sativa as protective agents: a histomorphometric and ultrastructural study

The study aimed to assess the toxic effect of cadmium (Cd) on the exocrine and endocrine functions of pancreas, the changes in pancreatic tissue after Cd withdrawal, and the protective effects of vitamin C (VC) and Nigella sativa (NS) against Cd-induced damage. Rats were assigned to: control, Cd-treated (0.5 mg/kg/d intraperitoneal [IP] injection), VC and Cd-treated (receiving 100 mg/kg/d VC orally and Cd concomitantly), NS and Cd-treated (receiving 20 mg/kg/d NS and Cd, simultaneously), and Cd withdrawal (receiving Cd for 30 d then living free for recovery for other 30 d). Blood samples were collected and post-sacrifice pancreatic specimens were processed for light and electron microscope study. Quantitative analyses of pancreatic collagen area%, pancreatic islet parameters, β cell density, and insulin immunoexpression were done. Fasting blood glucose was significantly increased in Cd-treated and Cd-withdrawal groups, while co-treatment with VC and NS caused significant reductions (p < 0.05). Cd-induced extensive degenerative changes in pancreatic acini and islets at light and ultrastructure levels. Obvious fibrosis and congestion of blood vessels were noticed. Significant reductions in pancreatic islet number, volume, and surface area and diminished beta cell count and insulin immunoexpression were observed. After withdrawal of Cd, the whole pancreatic tissue still showed a serious impact. Concomitant treatment with VC or NS obviously reduced these degenerative changes and significantly improved pancreatic islet parameters and insulin immunoexpression. VC showed a better amendment than NS, but this difference was statistically insignificant. Therefore, VC and NS could be used as prophylactic agents that lessen Cd consequences on the pancreas.

Role of Mitochondrial and Cytosolic Folylpolyglutamate Synthetase in One-Carbon Metabolism and Antitumor Efficacy of Mitochondrial-Targeted Antifolates.

Folate-dependent one-carbon (C1) metabolism encompasses distinct cytosolic and mitochondrial pathways connected by an interchange among serine, glycine, and formate. In both the cytosol and mitochondria, folates exist as polyglutamates, with polyglutamylation catalyzed by folylpolyglutamate synthetase (FPGS), including cytosolic and mitochondrial isoforms. Serine is metabolized by serine hydroxymethyltransferase (SHMT)2 in the mitochondria and generates glycine and C1 units for cellular biosynthesis in the cytosol. AGF347 is a novel pyrrolo[3,2-day]pyrimidine antifolate that targets SHMT2 in the mitochondria and SHMT1 and de novo purine biosynthesis in the cytosol. FPGS is expressed in primary pancreatic cancer specimens, and FPGS levels correlate with in vitro efficacies of AGF347 toward human pancreatic cancer cells. MIA PaCa-2 pancreatic cancer cells with CRISPR knockout of FPGS were engineered to express doxycycline-inducible FPGS exclusively in the cytosol (cFPGS) or in both the cytosol and mitochondria (mFPGS). Folate and AGF347 accumulations increased in both the cytosol and mitochondria with increased mFPGS but were restricted to the cytosol with cFPGS. AGF347-Glu5 inhibited SHMT2 ∼19-fold greater than AGF347 By metabolomics analysis, mFPGS stimulated the C1 flux from serine in the mitochondria and de novo purine and dTTP synthesis far greater than cFPGS. mFPGS enhanced in vitro inhibition of MIA PaCa-2 cell proliferation by AGF347 (∼30-fold) more than cFPGS (∼4.9-fold). Similar results were seen with other pyrrolo[3,2-d]pyrimidine antifolates (AGF291, AGF320); however, elevated mFPGS adversely impacted inhibition by the nonclassical SHMT2/SHMT1 inhibitor SHIN1. These results suggest a critical role of mFPGS levels in determining antitumor efficacies of mitochondrial-targeted pyrrolo[3,2-d]pyrimidine antifolates for pancreatic cancer. SIGNIFICANCE STATEMENT: AGF347 is a novel pyrrolo[3,2-d]pyrimidine antifolate that targets serine hydroxymethyltransferase (SHMT)2 in the mitochondria and SHMT1 and de novo purine biosynthesis in the cytosol. AGF347 accumulation increases with folylpolyglutamate synthetase (FPGS) levels in both the cytosol and mitochondria. Increased mitochondrial FPGS stimulated one-carbon metabolic fluxes in the cytosol and mitochondria and substantially enhanced in vitro inhibition of pancreatic cancer cells by AGF347. Mitochondrial FPGS levels play important roles in determining the antitumor efficacies of pyrrolo[3,2-d]pyrimidine antifolates for pancreatic cancer.

Artificial Intelligence-based Segmentation of Residual Pancreatic Cancer in Resection Specimens Following Neoadjuvant Treatment (ISGPP-2): International Improvement and Validation Study.

Neoadjuvant therapy (NAT) has become routine in patients with borderline resectable pancreatic cancer. Pathologists examine pancreatic cancer resection specimens to evaluate the effect of NAT. However, an automated scoring system to objectively quantify residual pancreatic cancer (RPC) is currently lacking. Herein, we developed and validated the first automated segmentation model using artificial intelligence techniques to objectively quantify RPC. Digitized histopathological tissue slides were included from resected pancreatic cancer specimens from 14 centers in 7 countries in Europe, North America, Australia, and Asia. Four different scanner types were used: Philips (56%), Hamamatsu (27%), 3DHistech (10%), and Leica (7%). Regions of interest were annotated and classified as cancer, non-neoplastic pancreatic ducts, and others. A U-Net model was trained to detect RPC. Validation consisted of by-scanner internal-external cross-validation. Overall, 528 unique hematoxylin and eosin (H & E) slides from 528 patients were included. In the individual Philips, Hamamatsu, 3DHistech, and Leica scanner cross-validations, mean F1 scores of 0.81 (95% CI, 0.77-0.84), 0.80 (0.78-0.83), 0.76 (0.65-0.78), and 0.71 (0.65-0.78) were achieved, respectively. In the meta-analysis of the cross-validations, the mean F1 score was 0.78 (0.71-0.84). A final model was trained on the entire data set. This ISGPP model is the first segmentation model using artificial intelligence techniques to objectively quantify RPC following NAT. The internally-externally cross-validated model in this study demonstrated robust performance in detecting RPC in specimens. The ISGPP model, now made publically available, enables automated RPC segmentation and forms the basis for objective NAT response evaluation in pancreatic cancer.

SCG2 and CPE may be novel markers for the identification of pancreatic neuroendocrine tumors and solid pseudopapillary neoplasms.

Distinguishing pancreatic neuroendocrine tumors (pNETs) from solid pseudopapillary neoplasms (SPNs) is challenging, primarily due to their overlapping pathological characteristics. To address this, our study aims to identify and validate novel biomarkers that effectively differentiate between these two conditions. We focus on the exploration of new immunohistochemical markers to enhance this distinction. In this study, we analyzed genetic variations in pNETs and SPNs using the GSE43795 dataset from the Gene Expression Omnibus (GEO) database. Our approach was to identify genes with higher expression in pNETs compared to SPNs and normal pancreatic tissues. We conducted enrichment analyses to understand the functions of these genes. Furthermore, protein-protein interaction (PPI) network analysis was utilized to identify key genes associated with pNETs. Our sample consisted of 163 pancreatic tumor specimens, comprising 78 pNETs and 85 SPNs. We also collected clinicopathological data and used immunohistochemistry to measure the expression levels of these key genes. The enrichment analysis revealed that genes overexpressed in pNETs were mainly involved in signal release, vesicle transport, and ion pathway activation, playing significant roles in endocrine processes like insulin secretion, dopamine synapses, and circadian rhythm regulation. The PPI analysis identified secretogranin II (SCG2), carboxypeptidase E (CPE), and chromogranin A (CgA, CHGA) as key markers for differentiating pNETs from SPNs. Immunohistochemical validation of these markers demonstrated high sensitivity (SCG2: 98.7%, CPE: 97.4%) and specificity (100%), indicating their superior discriminative power compared to traditional markers like CgA, β-catenin, lymphoid enhancer-binding factor 1 (LEF1), and vimentin. Our study indicates that SCG2 and CPE are effective, novel immunohistochemical biomarkers for differentiating pNETs from SPNs.

OIP5-AS1 enhances the malignant characteristics and resistance to chemotherapy of pancreatic cancer cells by targeting miR-30d-5p/MARCH8

MARCH8, an E3 ubiquitin ligase, plays a crucial role in regulating various cellular processes such as protein degradation and signaling pathways and is implicated in the development and spread of pancreatic cancer. Analysis of pancreatic cancer tissues compared to adjacent normal tissues showed a decrease in miRNA-30d-5p levels and an increase in OIP5-AS1 and MARCH8 levels, as confirmed by qRT-PCR and Western blot analysis. The dual-luciferase reporter assay demonstrated a binding relationship between OIP5-AS1 and miRNA-30d-5p, as well as between miRNA-30d-5p and MARCH8 in PACN-1 cells, derived from a human pancreatic carcinoma specimen. Further investigations utilizing various assays revealed that OIP5-AS1 inhibited apoptosis and promoted cell proliferation, invasion, and migration in PACN-1 cells via the miRNA-30d-5p/MARCH8 axis in vitro. Tumor experiments in nude mice confirmed that OIP5-AS1 enhanced PACN-1 cell growth in vivo through the miRNA-30d-5p/MARCH8 axis. Additionally, OIP5-AS1 was found to activate downstream genes of the JAK-STAT pathway, namely IFNAR2, SOCS3, and JAK1, in PACN-1 cells. Furthermore, OIP5-AS1 increased the IC50 values for doxorubicin, gemcitabine, and cisplatin in PACN-1 cells, as determined by the Cell Counting Kit-8 assay. Overall, OIP5-AS1 was shown to promote aggressive traits and resistance to chemotherapy in PACN-1 cells through the miRNA-30d-5p/MARCH8 axis.

Diagnosis of pancreatic malignancies using an overnight-stored pancreatic juice cell block specimen

Background and aimsPancreatic juice cytology is useful for diagnosing pancreatic duct strictures and cystic lesions. However, some cases cannot be diagnosed using cytology. This study aimed to evaluate the utility of the overnight-stored pancreatic juice cell block (CB) method for diagnosing pancreatic disease. MethodsThis retrospective study included 32 patients who presented with pancreatic duct strictures or cystic lesions between 2018 and 2024. The sensitivity, specificity, and accuracy of the CB method and single/multiple pancreatic juice cytology were compared to evaluate the utility of the CB. ResultAn endoscopic nasopancreatic drainage tube was placed in the main pancreatic duct, and pancreatic juice was collected to create a CB specimen. The median amount of pancreatic juice collected was 180(30–200) mL, and the median number of cytological examinations was three(2–8). Of the 32 cases, 13 were malignant, and 19 were benign (non-malignant). The sensitivity was significantly higher for the CB method (62 %) than for single cytology(15 %, P = 0.0414), and there was no significant difference between CB and multiple cytology(54 %, P = 1.0). The specificity and accuracy were not significantly different between the CB method and single or multiple cytology. When multiple cytology and CB were combined, sensitivity improved to 77 %. The pathological findings of the CB specimens were similar to the surgical specimens, including immunohistochemistry. ConclusionThe overnight-stored pancreatic juice CB method was more effective than single cytology, with similar sensitivities to multiple cytology and can also be used for immunohistochemistry. The pancreatic juice CB method is useful for pancreatic juice assessment.

Intraoperative Frozen Section Evaluation of Pancreatic Specimens and Related Liver Lesions.

Frozen sections are essential in the surgical management of patients, especially those with pancreatic masses, because frozen sections can provide answers intraoperatively and aid in treatment decisions. Pancreas frozen sections are challenging because of the small tissue size, processing artifacts, neoadjuvant treatment effects, and concurrent pancreatitis-like obstructive changes. The authors present a review of intraoperative evaluation of pancreatic specimens. To provide an approach to the diagnosis of pancreatic adenocarcinoma on frozen sections and to discuss commonly encountered pitfalls. Indications for pancreas frozen sections and specific margin evaluation will be discussed. We will also review frozen section diagnosis of subcapsular liver lesions and tumors other than metastases of pancreatic ductal adenocarcinoma. Data sources included a literature review and the personal experiences of the authors. The features for diagnosis of pancreatic adenocarcinoma include disordered architecture, glands at abnormal locations, and atypical cytology. It is important to be aware of the pitfalls and clues on frozen section. The evaluation of resection margins can be challenging, and in the setting of the resection of cystic tumors, the key is the diagnosis of high-grade dysplasia or cancer. Finally, it is vital to remember the differential diagnosis for subcapsular liver lesions because not all lesions will be metastases of adenocarcinomas or bile duct adenomas. Frozen sections remain a useful tool for the intraoperative management of patients with pancreatic tumors.

Grading Cytologic Epithelial Atypia in Pancreatic Mucinous Cysts Predicts Patient Survival: Correlation With Histologic, Molecular, and Clinical Follow-Up

Cytologic examination of epithelial cells in cyst fluids from pancreatic mucinous cysts is the optimal method for identifying high-grade atypia (HGA), which may represent histologic high-grade dysplasia (HGD) or invasive carcinoma and thereby classify the cyst as high risk, warranting surgical resection. Cytologic features of HGA were previously described at our institution in 2013 and implemented thereafter, but performance of grading with these criteria has not yet been reported. In total, 1322 pancreatic cyst fluid specimens (2014-2021) were identified; all pathology reports and relevant clinical data were reviewed in detail; and 230 unique cysts (217 patients) contained neoplastic mucinous epithelium. Of the 230 cysts, 178 had low-grade atypia (LGA), and 52 had HGA. Ninety-seven cysts had histologic follow-up: 77 (79%) were resections and 20 (21%) were diagnostic surgical biopsies only. Moreover, 92 (95%) were confirmed neoplastic mucinous cysts, 3 were adenocarcinomas, and 2 were benign entities. Among histologically confirmed neoplastic mucinous cysts, 58 had low-grade dysplasia (LGD); 34 had HGD, of which 14 also had invasive carcinoma. A significantly higher proportion of cysts with HGA (63%) demonstrated at least HGD on follow-up compared to those with LGA (26%, P < .001). The sensitivity and specificity of HGA for accurately classifying a high-risk cyst were 54% and 81%, respectively. Of the 230 cysts, 146 (64%) cysts had corresponding next-generation sequencing results; 31% of HGA cysts harbored a high-risk mutation (TP53, CDKN2A, and/or SMAD4) vs 7% of LGA cysts (P < .001). Among cysts without histologic confirmation, 25% of HGA cysts had high-risk mutation vs 7% of LGA cysts. The grade of cytologic atypia was predictive of overall survival and recurrence-free survival (P < .001 and P = .020, respectively). Implementation of cytologic criteria for HGA in pancreatic mucinous cysts has relatively low sensitivity but modest specificity for classifying a high-risk cyst. Although high-risk mutations were more commonly found in cysts with HGA, their frequency is overall low. Thus, evaluating the degree of cytologic atypia, which is predictive of patient survival, provides significant value and informs patient outcomes.

INSM1 is a useful neuroendocrine marker to differentiate pancreatic serous cystadenoma from pancreatic well-differentiated neuroendocrine tumors in cytology and surgical specimens

IntroductionDifferentiating pancreatic serous cystadenoma (SCA) from well-differentiated neuroendocrine tumors (WDNETs) based on histomorphology is critical yet challenging, particularly in small biopsy samples. Our study aimed to examine the expression profile of INSM1 in cytologic and surgical resection specimens from pancreatic SCA to evaluate its potential as a discriminative marker against pancreatic WDNET. MethodsWe characterized INSM1 immunohistochemistry in 34 patients with pancreatic SCA, comprising 23 surgical resections and 11 cytology specimens. As a control, we used 28 cytology specimens from pancreatic WDNET. Clinical information was retrieved through a review of electronic medical records. ResultsAll 11 pancreatic SCA cytology specimens and 15 of 23 pancreatic SCA surgical resections exhibited absent INSM1 immunostaining. Each of the remaining eight surgical resection specimens demonstrated 1 % immunoreactivity. In contrast, 27 out of 28 (96 %) pancreatic WDNET cytology specimens were positive for INSM1 immunostaining, with a median immunoreactivity of 90 % and a range of 30–90 %. Overall, INSM1 immunostains perform similarly to chromogranin and synaptophysin in pancreatic SCA. ConclusionsThe results indicate that INSM1 immunohistochemistry staining may serve as a useful neuroendocrine marker to differentiate pancreatic SCA from pancreatic WDNET in clinical practice. To our knowledge, this represents the first large-scale study to evaluate INSM1 immunostaining in surgical and cytology specimens from pancreatic SCA.

Effects of standardized sampling of fresh specimens on lymph nodes detection in radical pancreatic surgery specimens

Effects of standardized sampling of fresh specimens on lymph nodes detection in radical pancreatic surgery specimens

Abstract LB190: Cancer-stromal cells interaction dominates the expression of pro-tumor decreted protein chitinase-3-like-1 in pancreatic cancer

Abstract In the context of the tumor microenvironment (TME), a substantial increased secreted protein, chitinase-3 like-protein-1 (CHI3L1) has been observed, emanating from various cell types such as cancer cells, macrophages, and T cells. The development of an immunosuppressive and fibrotic TME has been implicated in CHI3L1-mediated cancer progression. Despite recognizing the potential for CHI3L1 blockade to facilitate cancer regression, there remains a limited understanding of the regulatory mechanisms governing the expression of this tumor-promoting protein within cancer cells. Our investigations, along with others, have identified low levels of CHI3L1 protein in normal epithelial cells, in stark contrast to its abundant presence in pancreatic cancer tumor specimens. We propose that the interaction between cancer and stromal cells in the TME induces CHI3L1 expression within cancer cells. To test this hypothesis, we established a co-culture system involving cancer and stromal cells including pancreatic stellate cells, macrophages and T cells to emulate the TME of pancreatic cancer. Subsequently, we observed a ten-fold increase in CHI3L1 expression in cancer cells upon exposure to co-culture media. Through secretomic analysis, C-X-C motif chemokine ligand 10 (CXCL10) emerged as a potential inducer of CHI3L1 expression in response to co-culture media. CXCL10/CXCR3 signaling has been reported to correlate with poor prognosis in pancreatic cancer, while their role in disease development is still unclear. Concurrently, Gene Set Enrichment Analysis (GSEA) identified the activation of TNFα signaling via NF-κB and TGF-β pathways in pancreatic cancer patients with high CHI3L1 expression. Notably, chromatin-immunoprecipitation and promoter activity assays validated the direct binding and transcriptional regulatory role of NF-κB, a downstream transcription factor of CXCL10, on CHI3L1 gene in cancer cells. In addition, epigenetic reprogramming occurred during co-culture media education. Our observations indicated demethylation of the CHI3L1 promoter during co-culture media exposure, a phenomenon confirmed to be mediated by STAT3 activation. In summary, this study elucidates, for the first time, the intricate crosstalk between cancer and stromal cells within the TME of pancreatic cancer as a pivotal factor for the transcriptional and epigenetic dysregulation of CHI3L1, which then contributes to TME remodeling and malignant pancreatic cancer progression. Citation Format: Pei-Chia (Peggy) Su, Yi-Ching Wang. Cancer-stromal cells interaction dominates the expression of pro-tumor decreted protein chitinase-3-like-1 in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB190.

K-ras mutation detected by peptide nucleic acid-clamping polymerase chain reaction, Ki-67, S100P, and SMAD4 expression can improve the diagnostic accuracy of inconclusive pancreatic EUS-FNB specimens

ObjectivesWe aimed to assess the diagnostic utility of an immunohistochemical panel including calcium-binding protein P, p53, Ki-67, and SMAD family member 4 and K-ras mutation for diagnosing pancreatic solid lesion specimens obtained by endoscopic ultrasound-guided fine-needle biopsy and to confirm their usefulness in histologically inconclusive cases. MethodsImmunohistochemistry and peptide nucleic acid-clamping polymerase chain reaction for K-ras mutation were performed on 96 endoscopic ultrasound-guided fine-needle biopsy specimens. The diagnostic efficacy of each marker and the combination of markers was calculated. The diagnostic performances of these markers were evaluated in 27 endoscopic ultrasound-guided fine-needle biopsy specimens with histologically inconclusive diagnoses. A classification tree was constructed. ResultsK-ras mutation showed the highest accuracy and consistency. Positivity in more than two or three of the five markers showed high diagnostic accuracy (94.6 % and 93.6 %, respectively), and positivity for more than three markers showed the highest accuracy for inconclusive cases (92.0 %). A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 showed high diagnostic performance, with only two misclassifications in inconclusive cases. ConclusionsK-ras mutation detection via peptide nucleic acid-clamping polymerase chain reaction is a stable and accurate method for distinguishing between pancreatic ductal adenocarcinoma and non-pancreatic ductal adenocarcinoma lesions. A classification tree using K-ras mutation, Ki-67, S100P, and SMAD4 helps increase the diagnostic accuracy of cases that are histologically difficult to diagnose.

Abstract 5506: HOST-Factor: A comprehensive platform for single-cell highplex immunofluorescence staining, digital imaging, spatial mapping, and quantitative analysis of the tumor microenvironment

Abstract Solid tumor complexity extends beyond the genetic and functional landscapes of heterogenous cancer cells, encompassing the tumor microenvironment (TME). Elucidating the TME’s complexity requires a comprehensive assessment of its cellular composition, functional states, and spatial distributions. We developed the Harmonic Output of Stromal Traits (HOST) to identify TME cells, and the HOST-Factor to quantify their functional states. The HOST-Factor is a numerical value that reflects the relative contribution of cancer-associated fibroblasts (CAFs) to tumor-suppressive or tumor-promoting functions. Our workflow combines automated cycling highplex immunofluorescent microscopy with artificial intelligence (AI)-guided image analysis. This generates HOST-Factor values for each identified TME cell within selected regions of interest, providing spatial distribution data. The TME signature encompasses 15 immune cells and 14 CAF antibody-detected biomarkers. We applied our workflow to ten human pancreatic cancer specimens, generating OME-TIFF output images. This cancer model was used due to its significant TME makeup. The 29 highplex AI-based digital image analysis was conducted using the Phenoplex™ workflow from Visiopharm. The workflow included deep-learning-based tissue morphologic and cellular segmentations, cellular phenotyping, and integration of spatial/location data. Biomarker subsets were visualized, and a user-trained algorithm was used for tissue segmentation. Nuclear segmentation was done using a pre-trained algorithm on a DAPI-labeled DNA channel. Cellular phenotyping was performed using thresholds based on visual assessment and confirmation of positivity. Spatial neighborhood plots and metrics, heatmaps and partitioned t-SNE plots were generated for the dataset for downstream analysis. Importantly, the workflow's visualization templates, pre-trained nuclear/cytoplasm segmentation tools, and neighborhood plots and metrics, are reusable and fully customizable for new datasets. Using HOST-Factor values, we successfully classified cancer and TME cells, along with their functional states, and spatial distributions. This AI-based computational approach and user-friendly workflow provides a simple and effective way to obtain single-cell information from multiplex immunofluorescence images, making spatial phenotyping of several cell populations in tissues more accessible to researchers, providing a fully amendable means for future clinical translation. Citation Format: Janusz Franco-Barraza, Fabian Schneider, Rasmus Norré-Sørensen, Rasmus Ahrenkiel-Lyngby, Caneta Brown, Dan Winkowski, James Robert Mansfield, Edna Cukierman. HOST-Factor: A comprehensive platform for single-cell highplex immunofluorescence staining, digital imaging, spatial mapping, and quantitative analysis of the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5506.

Abstract 2514: Adjuvant chemotherapy drug response-related gene detection using JASPAC01 pancreatic cancer resection cohort

Abstract Background of Purpose: Although various multidisciplinary treatments have been attempted for pancreatic cancer, sufficient improvement in prognosis has not been achieved. It is necessary to establish biomarkers that can predict the malignant potential for each patient and the therapeutic effect of chemotherapy in order to select the optimal treatment for each individual case.This study was designed as a companion study to the phase III comparative study (JASPAC 01 of gemcitabine (GEM) and S-1 therapy as adjuvant chemotherapy after pancreatectomy. Among the 22 candidate biomarker genes that have been reported to be involved in pancreatic cancer treatment prognosis, we focused on E2F transcription factor 7 (E2F7), which is associated with a significantly poor overall survival rate when highly expressed. E2F7 is one of the target proteins of p53 and has been reported to be involved in cell cycle regulation. We examined the possibility of E2F7 expression in pancreatic cancer surgery and the effect of adjuvant chemotherapy. Patients and Methods: After optimizing the E2F7 imunostaining protocol, we scored E2F7 protein expression using the slides from excised tissues from JASPAC 01 registered cases. We investigated the relationship between malignancy and treatment efficacy using the case cohort treatment allocation information, clinicopathological information, and prognosis data. Results: Immunostaining was performed on approximately 330 resected pancreatic cancer specimens from 24 facilities nationwide. Of the 311 patients for whom E2F7 protein expression could be scored, 202 patients who completed the assigned treatment were included in the analysis. In 88 cases with high E2F7 expression, no significant difference in clinicopathological factors was observed between the S-1 treatment group and the GEM treatment group, but the S-1 treatment group showed better recurrence-free survival (RFS, P=0.066) and overall survival (OS, P=0.015) were observed. On the other hand, in the 114 patients with low E2F7 expression, there was no significant difference in clinicopathological factors between the two groups (RFS, P=0.168, OS: P=0.276). High E2F7 expression in pancreatic cancer tissues may affect S-1 sensitivity, GEM resistance, or both. Conclusions: It is considered that high expression E2F7 in pancreatic cancer may affect the therapeutic efficacy of GEM and S-1, which are frequently used in adjuvant chemotherapy for pancreatic cancer. Citation Format: Yukiyasu Okamura, Tomohisa Otsu, Masamichi Hayashi, Ryo Ashida, Katsuhiko Uesaka. Adjuvant chemotherapy drug response-related gene detection using JASPAC01 pancreatic cancer resection cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2514.

Evaluation of pancreatic cancer specimens for comprehensive genomic profiling.

Inadequate specimen quality or quantity hinders comprehensive genomic profiling in identifying actionable mutations and guiding treatment strategies. We investigated the optimal conditions for pancreatic cancer specimen selection for comprehensive genomic profiling. We retrospectively analyzed 213 pancreatic cancer cases ordered for comprehensive genomic profiling and compared results from pancreatic biopsy, liver biopsy of pancreatic cancer metastases, pancreatectomy, liquid, and nonliver metastatic organ specimens. We examined preanalytical conditions, including cellularity (tumor cell count/size). The successfully tested cases were those that underwent comprehensive genomic profiling tests without any issues. The successfully tested case ratio was 72.8%. Pancreatic biopsy had the highest successfully tested case ratio (87%), with a high tumor cell percentage, despite the small number of cells (median, 3425). Pancreatic biopsy, liver biopsy of pancreatic cancer metastases, and non-liver metastatic organ had higher successfully tested case ratios than that for pancreatectomy. Liver biopsy of pancreatic cancer metastases and pancreatectomy cases with tumor size (mm2) × tumor ratio (%) > 150 and >3000, respectively, had high successfully tested case ratios. The success of comprehensive genomic profiling is significantly influenced by the tumor cell ratio, and pancreatic biopsy is a potentially suitable specimen for comprehensive genomic profiling.

Microscopic tumor mapping of post-neoadjuvant therapy pancreatic cancer specimens to predict post-surgical recurrence: A prospective cohort study

BackgroundAlthough various pathological grading systems are available for evaluating the response of pancreatic ductal adenocarcinoma (PDAC) to neoadjuvant therapy (NAT), their prognostic value has not been thoroughly validated. This study examined whether microscopic tumor mapping of post-NAT specimens could predict tumor recurrence. MethodsThis prospective study enrolled 52 patients who underwent pancreaticoduodenectomy after NAT for PDAC between 2019 and 2021. Microscopic mapping was performed to identify residual tumor loci within the tumor bed using 4 mm2 pixels. Patients were divided into small extent (SE; n = 26) and large extent (LE; n = 26) groups using a cutoff value of 226 mm2. The diagnostic performance for predicting tumor recurrence was evaluated using receiver operating characteristic (ROC) curves. ResultsCarbohydrate antigen 19-9 levels were normalised after NAT in more patients in the SE group (SE 21 [80.8%] vs. LE 13 [50.0%]; P = 0.041). Tumor size (P < 0.001), T stage (P < 0.001), positive lymph node yield (P = 0.024), and perineural invasion rate (P = 0.018) were significantly greater in the LE group. The 3-year disease-free survival rate was significantly lower in the LE group (SE 83.3% vs. LE 50.0%, P = 0.004). The area under the ROC curve for mapping extent was 0.743, which was greater than that of the other tumor response scoring systems. ConclusionsMicroscopic tumor mapping of the residual tumor in post-NAT specimens is a significant predictor of post-surgical recurrence, and offers better prognostic performance than the current grading systems.