Blood Biomarkers and Gut Microbiota for Pancreatic Cancer Risk in Chronic Pancreatitis

Chronic pancreatitis is associated with an increased risk of pancreatic ductal adenocarcinoma, but the biological changes that occur during disease progression remain incompletely understood. Changes in circulating inflammatory and immune-related biomarkers, disruption of the gut microbiota, and the movement of microbial products from the intestine into the bloodstream may reflect interactions among chronic inflammation, gut microbial imbalance, and impaired immune surveillance.

This is a single-center, prospective observational cohort study conducted at Changhai Hospital. The study plans to enroll up to 800 participants, including 200 healthy controls, 300 participants with chronic pancreatitis, and 300 patients with newly diagnosed pancreatic ductal adenocarcinoma. Healthy controls will serve as a reference group. Participants with chronic pancreatitis will form the main longitudinal cohort, and patients with pancreatic ductal adenocarcinoma will serve as the pancreatic cancer comparison cohort.

At baseline, participants will provide peripheral blood and fresh stool samples. Blood samples will be used to measure inflammatory, immune-related, and tumor-associated biomarkers, including CXCL10 (IP-10), GLYR1, TGF-beta, Artemin, and other candidate biomarkers. Markers related to gut barrier dysfunction and the movement of microbial products into the circulation, such as lipopolysaccharide, endotoxin-related measures, and soluble CD14, may also be assessed.

Stool samples will be analyzed using 16S ribosomal RNA gene sequencing, metagenomic sequencing, and related microbiome analysis methods. These analyses will characterize microbial diversity, taxonomic composition, functional pathways, and selected microbial metabolites, including pathways related to short-chain fatty acids and bile acids. Whenever feasible, blood and stool samples collected at the same time point will be analyzed as paired samples to investigate associations between circulating biomarkers and gut microbiota features.

Participants with chronic pancreatitis will generally be followed every 6 to 12 months. Follow-up may occur earlier or more frequently if there are changes in the participant's condition, an acute episode, imaging progression, an important treatment, or another clinical reason for evaluation. Follow-up information will include treatment, changes in disease status, laboratory test results, abdominal imaging findings, and relevant clinical outcomes.

Patients with pancreatic ductal adenocarcinoma will also be followed after enrollment according to their routine clinical care and follow-up schedule. Follow-up will be conducted through review of electronic medical records, outpatient or inpatient visits, and telephone contact when necessary. Information collected will include subsequent treatment, disease progression, recurrence or metastasis, laboratory and imaging results, survival status, and other relevant outcomes. Follow-up will continue until the end of the study, withdrawal from the study, or death.

Biological samples will not be routinely collected at every follow-up visit. Additional blood or stool samples may be collected from selected participants with chronic pancreatitis or pancreatic ductal adenocarcinoma when considered appropriate by the investigators or when participants express a willingness to provide additional samples. Before each additional sample collection, the participant's voluntary agreement will be reconfirmed. Refusal to provide an additional sample will not affect continued information follow-up or routine medical care. No research tissue samples will be collected from patients with pancreatic ductal adenocarcinoma during follow-up, and the study will not require additional imaging examinations, treatment, or invasive tissue sampling solely for research purposes.

Clinical information, laboratory results, abdominal computed tomography or magnetic resonance imaging data, and selected genetic information will also be collected when available. The main analyses will compare blood biomarker concentrations, gut microbiota diversity, microbial composition, and microbial functional features among the three groups. Longitudinal analyses will evaluate changes over time and their associations with clinical outcomes in participants with chronic pancreatitis and pancreatic ductal adenocarcinoma.

Candidate blood biomarkers and microbiota-derived features will be integrated with available immune-related, clinical, imaging, and genetic data. The study will develop and internally evaluate a multimodal model for pancreatic cancer risk stratification in participants with chronic pancreatitis. Model performance will be assessed using measures of discrimination, calibration, sensitivity, specificity, and clinical utility. No study treatment, experimental drug, or experimental medical device will be assigned to participants.

Inclusion criteria

• Adults aged 18 years or older.
• Able to understand the study procedures and provide written informed consent.
• Healthy controls: participants without a known history of chronic pancreatitis or pancreatic cancer.
• Chronic pancreatitis cohort: participants diagnosed with chronic pancreatitis according to clinical guidelines, based on clinical, imaging, and/or genetic information.
• Pancreatic ductal adenocarcinoma cohort: participants with newly diagnosed pancreatic ductal adenocarcinoma based on clinical, imaging, and/or pathological evaluation.
• Willing to provide blood samples and relevant clinical information.
• For participants with chronic pancreatitis, willing to undergo longitudinal follow-up approximately every 6 to 12 months.

Exclusion criteria

• Unable or unwilling to provide written informed consent.
• Unable to provide required clinical information or biological samples.
• Prior diagnosis of another active malignant tumor, except adequately treated non-melanoma skin cancer or carcinoma in situ, if considered not to affect study participation by the investigator.
• Current severe acute infection or other serious medical condition that, in the investigator's judgment, may interfere with study participation or interpretation of immune-related analyses.
• Use of systemic immunosuppressive therapy or immunotherapy within a period considered clinically relevant by the investigator.
• Any condition that, in the investigator's judgment, makes the participant unsuitable for this study.