Purpose The microbiome is increasingly recognised as a contributor to pancreatic ductal adenocarcinoma (PDAC) pathogenesis, presenting opportunities for biomarker discovery and therapeutic intervention. Characterising microbial signatures associated with PDAC could improve early detection to improve survival outcomes. Experimental Design While previous studies on the PDAC microbiome have focused primarily on faecal samples, this study employed 16S rRNA gene amplicon sequencing to profile the bacteriome across 226 biospecimens ( n = 111 PDAC, n = 115 control) collected from the mouth, stomach, duodenum, bile and pancreas. We assessed alpha and beta diversity, taxonomic composition, relative abundance and prevalence of bacterial communities across these upper gastrointestinal tract sites. Results Microbial diversity was significantly higher in the PDAC cohort, particularly in the stomach, duodenum and bile, with the latter showing unexpectedly high richness. While five dominant phyla (Pseudomonadota, Bacillota, Actinomycetota, Bacteroidota and Fusobacteriota) were shared between cohorts, the PDAC cohort harboured a greater number of unique low‐abundance taxa and displayed distinct site‐specific microbial profiles compared with control samples. Notable microbial shifts included enrichment of Pseudomonas , Acinetobacter , Geobacillus and Corynebacterium , genera previously implicated in inflammation, immune modulation and tumour persistence. Microbial clustering was strongly influenced by anatomical site and moderately by ethnicity, suggesting complex host–microbiome interactions in PDAC. Conclusions This study demonstrates distinct, site‐specific microbial variation in PDAC and supports an association for the microbiome in PDAC development and progression, warranting further mechanistic investigation.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer and was ranked among the top seven leading causes of cancer-related deaths in South Africa in 2020. Highlighting the urgent need for ongoing research to identify reliable biomarkers to improve clinical outcomes. This study compared the plasma proteomes of patients with PDAC, those with benign biliary pathologies (BBP), and healthy controls (HC). We used Mag-Net, a magnetic-bead-based method that enriches membrane-bound vesicles. Comparative analyses identified distinct and overlapping dysregulated proteins between PDAC, BBP, and HC. PDAC showed enrichment for epithelial-mesenchymal transition, complement activation, hypoxia, glycolysis, and extracellular matrix remodeling pathways, consistent with aggressive tumor biology. Proteins including SPP1, THBS2, PTX3, FBLN2, SDC1, CTSS, and VCAN were significantly increased in PDAC, with LRG1 showing the strongest association with disease severity. Proteins, namely GPNMB, H4C1, SAA1, and CCDC47, demonstrated progressive upregulation across disease comparisons, suggesting potential relevance to disease progression. These findings demonstrate that plasma proteomics provides discriminatory molecular insights and supports the development of population-relevant biomarker panels. While several candidate proteins show promise for inclusion in multianalyte panels, further validation in larger cohorts is necessary to establish their diagnostic and translational utility for early detection, risk stratification, and improved differential diagnosis of PDAC.

Background Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas present a broad spectrum of biological behavior, ranging from benign to malignant. Their management poses significant ethical dilemmas, particularly concerning diagnostic uncertainty, the risk of overdiagnosis and overtreatment, and resource allocation. Methods This qualitative study employed a constructivist approach to explore the ethical challenges faced by surgeons in managing IPMNs. Data were collected through focus group meetings (FGMs) with members of an expert working group at the Verona Evidence-Based Meeting on IPMNs (2020). Discussions were analyzed to identify key ethical concerns. Results The analysis highlighted several major ethical concerns: (1) decision-making under diagnostic uncertainty, (2) ethical challenges in patient communication, (3) overdiagnosis and over-surveillance due to defensive medicine and patient anxiety, (4) overtreatment through unnecessary surgery, and (5) issues of distributive justice in access to care and healthcare resource utilization. Participants emphasized the difficulty of balancing transparency with the need to minimize psychological distress in patients, as well as the challenge of applying international guidelines in diverse healthcare settings. Conclusions Ethical decision-making in IPMN management requires balancing the risks of malignancy with the potential harms of overtreatment, while also considering patient autonomy and resource limitations. Enhancing decision-support tools, improving surgeon training in communication, and refining clinical guidelines to incorporate ethical considerations may help address these challenges. Further research is needed to develop strategies for more individualized and patient-centered care.

Abstract Background: Pancreatic Ductal Adenocarcinoma (PDAC) remains one of the most lethal cancers globally, with increasing incidence among Black African populations. Emerging evidence suggests that the interplay between metabolic dysregulation and inflammation may play crucial roles in the pathogenesis and progression of PDAC. However, this relationship remains underexplored in African cohorts. Methods: We conducted an untargeted metabolomics study using Nuclear Magnetic Resonance (NMR) spectroscopy on plasma samples obtained from consenting participants comprising 81 PDAC patients (57 resectable, 15 locally advanced, and 9 metastatic), 6 chronic pancreatitis patients, and 6 healthy controls. Reactive oxygen species (ROS) levels were quantified using the OxiSelect™ In Vitro ROS/RNS Assay Kit (Green Fluorescence). Group comparisons were performed using Wilcoxon and Kruskal-Wallis rank-sum tests, while Spearman’s correlation and Kaplan-Meier analyses were applied for correlation and survival assessment. A p-value < 0.05 was considered statistically significant. Results: Total bilirubin (p = 0.004), conjugated bilirubin (p = 0.003), alanine aminotransferases (p = 0.01) and aspartate aminotransferases (p = 0.03) levels were significantly altered across the groups. Metabolomic profiling revealed elevated levels of 2-hydroxybutyrate (2-HB, p = 0.004) and acetoacetate (p = 0.009) with advancing tumor stage. PDAC patients were stratified into “high” and “normal/low” 2-HB groups, with the top 25% representing the “high” group. Furthermore, lower 2-HB concentrations were associated with longer survival outcomes. Although not statistically significant, patients with high 2-HB exhibited increased ROS/RNS levels compared to those with low 2-HB. There was a positive correlation between 2-HB and inflammatory markers: GlycA (rho=0.07, p=0.64), GlycB (rho=0.07, p=0.66), CRP (rho=0.49, p=0.08) and White cell count (rho=0.48, p=0.08). Conclusion: This study demonstrates a potential link between altered metabolic pathways and oxidative stress in Black African PDAC patients. Elevated 2-HB and acetoacetate may serve as metabolic indicators of tumor progression and poor prognosis. These findings highlight the importance of integrating metabolic and inflammatory profiling to better understand PDAC biology in African populations. Citation Format: Nnenna Elebo, Dupe Ojo, Jones Omoshoro-Jones, Stefano Cacciatore, John Devar, Ekene E. Nweke. The link between metabolism and inflammation in Black African pancreatic ductal adenocarcinoma patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 7321.

Background: Gall bladder cancer (GBC) is the most common biliary tract malignancy and is often diagnosed at advanced stages, partly due to the absence of reliable biomarkers and limited understanding of its biology in African populations. This study aimed to characterize the metabolomic and lipoprotein profiles of GBC patients of Black African ancestry. Methods: NMR spectroscopy was used to profile the serum samples. Group comparisons used Wilcoxon tests, correlations used Spearman’s rank test, unsupervised analysis was carried out using the KODAMA algorithm, partial least squares modeling estimated free cholesterol (FC) to cholesterol ester (CE) ratios, while multivariate logistic regression evaluated independent predictors. Results: GBC patients showed altered ethanol levels and dysregulated lipoproteins, including increased IDL-C, IDL-TG, and LDL-TG, and decreased HDL-C, HDL-P, and medium HDL-P. Total and conjugated bilirubin strongly correlated with lipoproteins. Unsupervised analysis revealed a GBC subgroup with abnormal lipoprotein profiles and elevated FC/CE ratios, suggesting cholestasis-related LpX formation. Elevated asparagine, reduced ethanol, and an inflammatory metabolic signature characterized the GBC fingerprint. Ethanol and bilirubin emerged as independent predictors of GBC. Conclusions: GBC patients exhibit distinct metabolomic and lipoprotein alterations that may underlie disease progression and serve as potential biomarkers. These findings enhance understanding of GBC pathophysiology in African populations and may inform future diagnostic strategies.

562 Background: As the sixth most common malignancy worldwide, hepatocellular carcinoma (HCC) accounted for 4.7% of all new cancer diagnoses in 2022. Low- and middle-income countries seem to bear a disproportionate burden of the disease, with over 50% of new HCC cases estimated to occur in China and Africa. Research on multidisciplinary team (MDT) practices in these regions is limited. The objective of this study is to compare MDT practices in the management of HCC in HICs and LMICs. Methods: Data on MDT practices from hospitals that manage HCC in Italy, Spain, Switzerland, Germany, Denmark, Canada and the USA, representing HICs, and in China, South Africa and Egypt, representing LMICs were collected through virtual semi-structured interviews and workshops. Results: Ten key areas of differences were identified (Table 1) that could be categorized as organizational/regulatory or clinical. In HIC institutions, the focus currently is on optimizing MDTs as standard of care approach accessible to all patients with HCC; MDT principles are often integrated into national policies. In LMICs, emphasis is on establishing MDTs and expanding their capacity; patient access to MDT care is not a mandatory requirement, nor regulated in national policy. Of note, LMICs are seeking early technology adoption to overcome some potential barriers to MDT interactions; online formats are more often explored to facilitate participation and AI-assisted diagnostic tools are explored to compensate for absence of radiologists. Absence of screening and surveillance for early detection in HCC is more common in LMICs, and therefore likely that patients more often present with advanced stage disease. Also, with limited diagnostic modalities, diagnostic work-up and staging may be sub-optimal. Conclusions: Significant variation exists in HCC MDT practices between HICs and LMICs. The ultimate goal of this study is to develop a format for clinical MDTs that will facilitate interaction between HICs and LMICs. Consideration for the differences highlighted above is crucial for the development of this concept. 10 key areas highlighting differences identified between HICs and LMICs. MDT development direction: Standard of Care for all patients vs. specific session for complex cases National/regional regulatory requirements Institutionalizing MDT principles MDT composition (specialists) Use of digital tools Reimbursement Access to therapeutic options Stage presentation of HCC patients Use of clinical staging Patient follow-up after MDT discussion

Gallbladder cancer (GBC) is a highly aggressive malignancy with limited therapeutic options, particularly in underrepresented populations, including South Africa. Understanding the molecular landscape of GBC may provide novel insights into its pathogenesis and potential therapeutic targets. Molecular changes are known to be associated with GBC, however, there is a paucity of this information especially in African populations. Furthermore, within the tumour microenvironment, different immune cells contribute to GBC progression. We investigated gene expression patterns in GBC tumours and their association with different immune cells in a cohort of South African patients. RNA sequencing was conducted on 2 normal and 8 gallbladder cancer tissues from South African patients to identify differentially expressed genes. Bioinformatics tools were used for pathway analysis, while immune cell quantification was performed using the quanTIseq software and presented as median [IQR]. Verification studies were further carried out using real-time PCR on an independent cohort comprising 7 gallstone samples and 26 gallbladder tumour samples. A total of 65 genes were found to be significantly differentially expressed between the gallbladder tumours and gallstone controls. We also identified 37 upregulated and 28 downregulated genes in this cohort. Among the most upregulated genes, MUC16 was confirmed to be significantly overexpressed in tumours. Normal tissues exhibited a significantly higher proportion of dysregulated genes associated with B cells (17.132 [14.866-18.483], p < 0.0001) and M1 macrophages (18.943 [1.097-36.790], p < 0.0001) compared to tumours. In contrast, tumours showed a greater association with dysregulated genes linked to regulatory T cells (Tregs) (14.373 [9.696-20.162]) relative to normal tissues. Pathway analysis further revealed the upregulation of defective GALNT12, defective GALNT3, defective C1GALT1C1 and termination of O-glycan biosynthesis, highlighting key mechanisms potentially involved in tumour progression. The study has shown the dysregulation of key genes in South African gallbladder cancer patients. Specifically, MUC16 was verified to be significantly elevated in tumour samples. Furthermore, the association of these dysregulated genes with key immune cells in this patient group may further highlight their roles in dysfunctional immune processes linked with tumourigenesis.

Background: Acute pancreatitis (AP) can be life-threatening with unpredictable severity. Despite advances in management, its pathogenesis remains unclear. This study investigated metabolites and lipoprotein profiles in AP patients of African descent to understand the underlying pathophysiological conditions so as to inform prognosis and management. Methods: Serum samples were collected from 9 healthy controls (HCs) and 30 AP patients (8 with mild AP, 14 with moderately severe AP, and 8 with severe AP) on days 1, 3, 5, and 7 post epigastric pain and subjected to nuclear magnetic resonance (NMR) spectroscopy. Wilcoxon and Kruskal–Wallis rank-sum tests compared numerical covariates. Lipoprotein characterization was performed using the Liposcale test, and Spearman’s rank test assessed data correlations. The p-values < 0.05 indicated significance. Results: Thirty-eight metabolic signals and information on lipoprotein subclasses were identified from the NMR spectra. The severity of AP correlated with increased levels of 3-hydroxybutyrate and acetoacetate and decreased levels of ascorbate. Distinct metabolic phenotypes were identified and characterized by unique inflammatory and lipoprotein profiles. High-density lipoprotein cholesterol (HDL-C) decreased across all the metabolic phenotypes of AP when compared with the HC, while elevated immediate density lipoprotein cholesterol (IDL-C) and very low-density lipoprotein cholesterol (VLDL-C) levels were observed. Time-dependent changes in metabolites were indicative of responsiveness to therapy. Conclusions: Our findings indicate that dysregulated metabolites and lipoproteins can be used to differentiate AP disease state and severity. Furthermore, integrating clinical parameters with data on metabolic and lipoprotein perturbations can contribute to a better understanding of the complex pathophysiology of AP.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a growing incidence and mortality despite novel therapeutic strategies. The complement signalling pathway may play diverse roles in PDAC by eliciting an immune response, inducing inflammatory responses, and may elevate pathways linked to chemoresistance. However, their role in the progression of PDAC is not fully understood. In this study, 30 tissues and 34 plasma samples were obtained from a cohort of PDAC patients including controls. Targeted pathway-specific PCR analysis was conducted to determine the gene expression profiles of immune-response-related genes. The circulating levels of complement proteins C3 and C5 were further investigated. Pharmacological inhibition of the complement pathway in MIA PaCa-2 pancreatic cancer cell lines was performed and the effect on cells was assessed by cell proliferation, cell migration, and cell cycle assays. Finally, SWATH-mass spectrometry was performed to identify potential molecular mechanisms during inhibition. The results identified C3 and C5 to be overly expressed in early PDAC compared to later stages. Pharmacological inhibition of the complement pathway led to increased cell growth, proliferation and migration in vitro . Proteomic analysis implicated several proteins such as the mitochondrial and histone proteins, that could play a role in inducing this phenotype. This study helps to further delineate the role of the complement pathway in PDAC progression suggesting a context-dependent function.

Pancreatic ductal adenocarcinoma (PDAC) is poised to be a leading cause of cancer-related deaths. Despite developing new treatment strategies, patient outcomes have not significantly improved. Chemoresistance has been implicated as a major contributor to ineffective treatments observed with studies suggesting combination therapy targeting multiple pathways. This study explored dysregulated genes in tumours of PDAC patients to identify targets which could be used effectively in combination with conventional therapy against cancer cells. In this study, PCR arrays were used for gene expression profiling of tumours obtained from South African PDAC patients to identify key differentially expressed pathways and potentially new therapeutic target genes. SPP1 was selected and RNA interference was used to knock the gene down. Migration and apoptosis assays were used to evaluate the effect of the knockdown, alone and in combination with Gemcitabine, on a pancreatic cancer cell line, MIA PaCa-2. Proteomic analysis using SWATH-MS was used to demonstrate potential molecular mechanisms linked to the morphological and phenotypical effects observed with treatment. We demonstrated several genes linked to the growth factor and signal transduction signalling pathways, and identified SPP1 as a target. We observed that by combining SPP1 knockdown with conventional chemotherapy, gemcitabine, resulted in a synergistic effect, leading to an enhanced early apoptotic response. A decline of migratory and invasive capabilities of MIA PaCa-2 cells was observed upon subjecting the cancer cells to SPP1 reduction and gemcitabine treatment. Furthermore, proteomic analyses uncovered several pathways that were dysregulated by the combination therapy including both pro-and anti-tumorigenic ones. The study findings indicate that SPP1 could be a potential therapeutic target for PDAC, and the possible synergistic effects observed when SPP1 knockdown was combined with gemcitabine treatment suggest a potential avenue for developing more effective treatments for PDAC while exploring tumour cell adaptation for survival.### Competing Interest StatementThe authors have declared no competing interest.### Funding StatementThe study was funded by the National Research Foundation grant (Grant number: 138367) and the Cancer Association of South Africa (CANSA). Proteomics infrastructure used was supported by DIPLOMICS, a research infrastructure initiative of the Department of Science and Innovation of South Africa. ### Author DeclarationsI confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.YesThe details of the IRB/oversight body that provided approval or exemption for the research described are given below:Ethics approval was obtained from the Human Research Ethics Committee (HREC) of the University of the Witwatersrand (Ethics number: M190735)I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.YesI understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).YesI have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.YesAll data produced in the present study are available upon reasonable request to the authors

IntroductionHepatopancreatobiliary (HPB) cancers encompassing malignancies of the liver, pancreas, gall bladder, and bile ducts pose a significant health burden in Africa. While the association of certain occupational carcinogens in cancer is well established globally, their potential role in HPB cancers remains understudied, especially in an African context.AimThis systematic review delves into the association between occupational carcinogens and HPB cancer in Africa. It examines the current state of research on occupational carcinogens and HPB cancers in Africa, identifying key challenges and knowledge gaps.MethodsThis systematic review examined publications (published between 01 January 2012 and 31 May 2023) that highlight occupational carcinogens and HBP cancers in Africa. The search was conducted on electronic databases namely PubMed, Web of Science, and Africa Wide Information.ResultDue to the lack of information on the association between occupational carcinogens and HPB cancers in Africa, as a result of the paucity of published studies, only four articles were included in this study. Hepatocellular carcinoma (HCC) was the predominant cancer associated with the occupational carcinogen, aflatoxin. Agricultural workers, especially those involved in the production and processing of maize and peanuts, appear to be the most exposed to aflatoxin.ConclusionDespite the sample size limitations due to the paucity of research studies on occupational carcinogens and HPB cancers in Africa, this study provides a reasonable tool for subsequent epidemiological studies. There is a need for more research on the association of occupational carcinogens and HPB cancers in Africa, especially with the growing industrialization.

Background: Common bile duct stones are a common hepatobiliary condition. Arguably, the first choice in their management is ERCP. However, this approach may occasionally fail due to the inability to cannulate the biliary tree or extract stones. With the increase in laparoscopic skills and availability, laparoscopic bile duct exploration (LCBDE) has become a common procedure worldwide. Objective: Retrospective review of transcholedochal LCBDE in a South African hospital with analysis of safety and efficacy of this technique. Methods: We retrospectively analyzed data from all patients who underwent transcholedochal LCBDE for choledocholithiasis in our institution between September 2017 and November 2022. Data pertaining to patient demographics, operation time, length of stay, and post operative outcomes including complications were evaluated and reported. Results: A total of 67 patients were included, 91% were females. The median age was 49 years (SD 12.95). Sixty six patients (98.5%) had one or more pre-operative attempts at ductal clearance at ERCP. All patients had transcholedochal exploration of their bile ducts, with a 98.5% duct clearance rate. The median total theatre time (push in to push out) was 317 minutes. There were 9 (13%) conversions to open surgery. The median length of stay was 6 days. A total of 6 (9%) patients had a Clavien Dindo grade 2 or 3 complicaton. These included pneumonia (n=6), liver abscess (n=3), bile leak (n=1), residual stones (n=1) and one port site hernia. There were no mortalities. Conclusion: Our experience shows that LCBDE is a safe and effective treatment modality with acceptable morbidity for management of choledocholithiasis after failed ERCP.

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with almost an equal number of incidences and mortality. Patients of African ancestry have the poorest prognosis but are relatively understudied. A previous study in our laboratory showed proteomic signatures in tumour samples. In this study, we sought to apply a liquid biopsy-based approach to identify proteins in plasma associated with PDAC patients. Method: Blood samples were obtained from 64 PDAC patients and 64 patients with benign biliary pathologies (as controls) who were admitted to Chris Hani Baragwanath Academic, Hospital, Johannesburg South Africa (Ethics number- M220735). Ten millilitres of blood was obtained from each recruited patient, processed into plasma and subsequently digested into peptides. A peptide amount of 0.5μg (based on peptide quant) of each sample was analysed with Evosep One coupled to AB Sciex TripleTOF 5600 mass spectrometer in a SWATH acquisition mode, with 48 VW (variable windows). Acquired MS/MS data were processed using SpectronautTM 16, using an in-house generated spectral library. A minimum 1.5-fold change and FDR-adjusted p-value (q-value) ≤ 0.01 were applied. Pathway analysis was performed using REACTOME v3.7. Results: A total of 23 upregulated and 15 downregulated when comparing PDAC plasma samples to the controls. The proteins were mainly involved in pathways such as platelet degranulation, acute-phase response, acute-inflammation response, and immune effector processes. Furthermore, we compared the expression of these dysregulated proteins to our previous study using tissue biopsies. Seven proteins were upregulated in both plasma and tissue samples, these included SAA4, APOL1, PON1, APOA1, APOA2, IGKV 1-5 and APOM. Four of the proteins were downregulated in plasma but upregulated in tissue samples including SAA1, SAA2, SERPINA3 and APOB. Conclusion: The study identified proteomic signatures in the plasma of South African PDAC patients. Some of these proteins have been associated with tumour progression and metastasis including SAA4, APOL1, PON1, and APOB. This helps our understanding of the disease progression in our population. Importantly, the proteins identified have potential utility as non-invasive biomarkers.