Abstract
Background
Postoperative pancreatic fistula (POPF) is the major driver of postoperative morbidity after pancreatoduodenectomy (PD) and a healthcare issue. In patients with pancreatic tumors the occurrence of POPF could lead to a complete failure of the oncologic strategy by delaying or annihilating the delivery of the indicated adjuvant chemotherapy. However, current preoperative prediction models lack precision. This study aimed to determine the ability of a high dimensional analysis of the patient’s peripheral immune system before PD to predict POPF.
Methods
Twenty-two patients in the prospective IMMUNOPANC trial (NCT03978702) underwent PD. Blood samples collected preoperatively were analyzed by combining single-cell mass cytometry and a sparse machine-learning pipeline, Stabl, to identify the most relevant POPF-predictive features. The logistic regression model output was evaluated using a five-fold cross-validation procedure.
Results
Eight (36%) patients experience POPF (grade B, n = 7; grade C, n = 1). The multivariable predictive model includes 11 features—six natural killer, three CD8+ T, and two CD4+ T lymphocyte cell clusters—revealing a preoperative POPF lymphocyte signature (Pancreatic Fistula Lymphocyte Signature, PFLS). The Stabl algorithm identifies a predictive model classifying POPF patients with high performance (area under the receiver operating characteristic curve=0.81, P = 2.04e-02).
Conclusions
In summary, preoperative circulating immune-cell composition can predict POPF in patients undergoing PD. The clinical application of the PFLS may enable the early identification of patients at high risk before pancreatic surgery, giving clinicians the opportunity to anticipate and mitigate POPF risk through tailored strategies in pre-, intra-, and post-operative settings.

Plain language summary
Pancreatic surgery is the cornerstone of treatment for patients with pancreatic tumors, but a serious complication called postoperative pancreatic fistula (POPF) often occurs. POPF can worsen recovery and delay critical chemotherapy, sometimes causing cancer treatment to fail. Current tools to predict which patients are at risk for POPF are not accurate enough. In this study, we tested whether analyzing immune cells in the blood with machine learning could better predict POPF before surgery. We found that this approach accurately identified patients at high risk for POPF. Early recognition of patients at risk of POPF could allow physicians to anticipate and reduce said risk through tailored strategies before, during, and after surgery, ultimately improving recovery and access to timely cancer treatment.
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Data availability
The datasets generated and/or analyzed during the current study are not publicly available because of patient privacy concerns but are available from the corresponding author upon reasonable request. The timeframe for response is within two weeks. Use of data is controlled by data transfer agreement. The source data for the figures is accessible in the corresponding supplementary data. Supplementary Data 1 was generated with the non-supervised dimensionality reduction algorithm of h-SNE implemented in Cytosplore (V2.2.1)29, and represents the Fig. 2. Of note, the workflow from PBMCs to h-SNE clustering has been previously reported22. The unit is the proportion of cells count. Supplementary Data 2, 3 and 4 were used to generate Fig. 3A. Supplementary Data 2 contains all immune clusters and the POPF outcome. Blood samples collected the day before surgery were used to calculate the absolute cell count for each immune cluster (unit: 10⁶ cells/L). Supplementary Data 3 contains the multiomic Stabl+logistic regression cross-validation for all the features, and Supplementary Data 4 contains the multiomic Stabl+logistic regression validation coefficients for the 11 clusters of the signature. Supplementary Data 5 was used to generate Fig. 3B, C, as well as Fig. 4. It contains the POPF outcome, the ua-FRS index, the PFLS result, the clinical and biological values for each patient.
Code availability
The analyses, results, and figures reported in this study were generated using Biomics Software, a proprietary machine-learning platform developed and maintained by SurgeCare. Consequently, the exact implementation code used in this study is not publicly available, as it forms part of a commercial software product. Importantly, Biomics Software is built upon established, openly available machine-learning methodologies. In particular, the core feature-selection methodology used in this study relies on the Stabl algorithm, which is fully described in the literature and whose reference implementation is publicly available (Hédou, J., Marić, I., Bellan, G. et al. Discovery of sparse, reliable omic biomarkers with Stabl. Nat Biotechnol 42, 1581–1593 (2024). https://doi.org/10.1038/s41587-023-02033-x). Additional foundational components rely on widely used open-source machine-learning libraries (e.g., Python-based scientific and machine-learning frameworks), which are freely accessible online. The full analytical workflow, including model design, training procedures, validation strategy, and evaluation metrics, is described in detail in the Methods section to ensure methodological transparency and reproducibility. Due to the proprietary nature of the Biomics Software platform, we are unable to deposit the full application code in a public repository or assign a DOI. However, access to the software for editorial or reviewer verification can be provided upon reasonable request, subject to appropriate confidentiality and usage agreements.
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Acknowledgements
This work was supported by the Fondation ARC (grant ARC#2022-00154 for ASC), the Groupement d’intérêt scientifique -Infrastructures pour la Biologie, la Santé et l’Agronomie (GIS IBiSA) and the National Institute of Health (grant R35GM137936 for BG). The team “Immunity and Cancer” was labeled “Equipe Fondation pour la Recherche Médicale (FRM) #2018-00198” (for D.O.).
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Conceptualization: Jonathan Garnier, Olivier Turrini, Anne-Sophie Chrétien and Daniel Olive; Data curation: Jonathan Garnier, Olivier Turrini, Marie Sarah Rouvière, and Amira Ben-Amara; Formal analysis: Jonathan Garnier, Anne-Sophie Chrétien, Marie Sarah Rouvière, Amira Ben-Amara, Gregoire Bellan, and Xavier Durand; Investigation: Jonathan Garnier, Olivier Turrini, and Anne-Sophie Chrétien; Methodology: Jonathan Garnier, Olivier Turrini, Anne-Sophie Chrétien, Daniel Olive, Gregoire Bellan, and Xavier Durand; Project administration: Jonathan Garnier, Olivier Turrini, and Caroline Gouarné; Resources: Jonathan Garnier, Olivier Turrini, Anaïs Palen, Jacques Ewald, Caroline Gouarné, Anne-Sophie Chrétien, Daniel Olive, Franck Verdonk, and Brice Gaudilliere; Software: Jonathan Garnier, Anne-Sophie Chrétien, Benjamin Choisy, Gregoire Bellan, and Xavier Durand; Writing—original draft: Jonathan Garnier, Anne-Sophie Chrétien, Gregoire Bellan, and Xavier Durand; Writing—review & editing: all authors.
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Garnier, J., Bellan, G., Palen, A. et al. Preoperative lymphocyte signature predicts pancreatic fistula after pancreatoduodenectomy. Commun Med (2026). https://doi.org/10.1038/s43856-026-01422-y
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DOI: https://doi.org/10.1038/s43856-026-01422-y


