This study aims to evaluate the role of the circulating epigenetic biomarker mSEPT9 in predicting the risk of hepatocellular carcinoma (HCC) in patients with cirrhosis. HCC is a primary liver cancer that frequently develops in individuals with cirrhosis, and early detection is critical for improving outcomes. This research involves 400 patients with cirrhosis who will be followed every six months for up to 60 months. During these visits, blood samples will be collected to analyze mSEPT9 levels. By identifying changes in this biomarker, the study seeks to improve early diagnosis and personalize surveillance strategies, potentially enhancing patient survival and quality of life.

This study is a prospective, multicenter cohort trial designed to assess the prognostic utility of the circulating epigenetic biomarker mSEPT9 in predicting the development of hepatocellular carcinoma (HCC) among patients with cirrhosis. The trial involves 400 participants who are confirmed to have cirrhosis and no evidence of HCC at baseline.

The study's primary focus is to evaluate the association between a "switch" in the mSEPT9 test-from a triple-negative status (no methylation detected across triplicate assays) to at least one positive triplicate-and the subsequent occurrence of HCC. Secondary objectives include assessing this association across different etiologies of cirrhosis (e.g., viral hepatitis, alcohol-related liver disease, nonalcoholic steatohepatitis) and its correlation with HCC-related mortality.

Participants will undergo standardized clinical, biological, and imaging assessments every six months over a follow-up period of 60 months, as per international guidelines for cirrhosis management. In addition to routine care, blood samples will be collected at each visit for mSEPT9 testing. These samples will be processed, stored at -80°C, and analyzed in batches to assess mSEPT9 levels.

The findings from this study are expected to address the unmet need for reliable, non-invasive biomarkers for HCC risk prediction, potentially leading to personalized surveillance strategies and earlier intervention for patients with cirrhosis. Data will be managed using an electronic case report form (eCRF) to ensure secure, standardized documentation across all participating centers. Results from mSEPT9 testing will not influence clinical management during the study period but will be analyzed to determine their predictive value for HCC development and prognosis.

Inclusion Criteria:

• Adults aged 18 years or older.
• Patients diagnosed with cirrhosis confirmed by clinical, biochemical, radiological, or histological criteria.
• Cirrhosis attributable to one or more of the following etiologies: alcohol, hepatitis C (HCV), hepatitis B (HBV), nonalcoholic steatohepatitis (NASH), hemochromatosis, autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, or cryptogenic causes.
• Patients actively followed in one of the participating study centers.
• Patients affiliated with a social security program or equivalent.
• Patients with a body weight greater than 45 kg.
• Patients who have been fully informed about the study procedures and have provided oral informed consent.

Exclusion Criteria:

• History of hepatocellular carcinoma (HCC).
• History of any other primary or secondary malignant liver tumor.
• Diagnosis of malignancy or hematologic disorders within the past 5 years (without time limitation for hematologic malignancies).
• Patients currently undergoing hemodialysis.
• Pregnant or breastfeeding women.
• Individuals under legal protection (e.g., guardianship, curatorship) or unable to provide consent.
• Minors or individuals younger than 18 years.
• Individuals deprived of liberty by judicial or administrative order.
• Patients with psychiatric conditions receiving care under legal constraints (e.g., articles L.3212-1 and L.3213-1).
• Patients unable to comply with the study protocol requirements.

The study population consists of 400 adult patients with confirmed cirrhosis who are actively followed in specialized hepatology centers across multiple institutions. Participants must not have hepatocellular carcinoma (HCC) at the time of enrollment and must meet specific inclusion criteria, including established cirrhosis etiology and eligibility for routine clinical follow-up. Patients with conditions that may interfere with the study objectives, such as a history of malignancy or ongoing hemodialysis, are excluded. This cohort represents a diverse range of cirrhosis etiologies, including viral hepatitis, alcohol-related liver disease, and nonalcoholic steatohepatitis (NASH), to ensure the generalizability of findings.

The study will share individual participant data (IPD) related to anonymized clinical, biological, and imaging results, as well as the results of mSEPT9 biomarker analyses.

This includes:

• Demographic data
• Clinical characteristics, including cirrhosis etiology and disease severity (e.g., Child-Pugh score)
• Results from routine imaging and biological assessments
• mSEPT9 test results (e.g., triple-negative, positive status)
• Outcome measures, such as the occurrence of hepatocellular carcinoma (HCC) and mortality

All shared data will be pseudo-anonymized to ensure participant confidentiality and will be accessible to researchers upon reasonable request, in accordance with regulatory and ethical guidelines.

The individual participant data (IPD) and supporting information will be available starting 12 months after the publication of the study results. IPD related to outcomes outside the primary and secondary objectives of the study may be discussed and shared on a case-by-case basis, contingent on appropriate approvals and compliance with applicable regulations.