Peripheral Blood Biomarkers and Response to Atezolizumab Plus Bevacizumab in Hepatocellular Carcinoma

This single-center prospective observational cohort study aims to evaluate the predictive value of peripheral blood-based biomarkers for treatment response in patients with hepatocellular carcinoma (HCC) receiving first-line atezolizumab plus bevacizumab (T+A) therapy. Residual peripheral blood samples obtained during routine clinical testing will be analyzed without additional blood draws. The study hypothesizes that baseline and longitudinal peripheral blood biomarkers are associated with treatment response and can be used to identify patients more likely to benefit from T+A therapy. Treatment response will be evaluated based on the best overall response (BOR) during treatment. The primary efficacy assessment will be performed according to RECIST 1.1, while modified RECIST (mRECIST) will be used as a supportive assessment. Predictive models based on peripheral blood biomarkers will be developed using RECIST 1.1-defined treatment response as the primary analysis, with mRECIST used for supportive and sensitivity analyses.

Inclusion Criteria: * Age 18-80 years * Histologically or clinically confirmed unresectable or advanced HCC, classified according to the BCLC staging system * Planned to receive first-line atezolizumab plus bevacizumab therapy, with no prior systemic therapy for unresectable or advanced HCC * At least one measurable target lesion with a longest diameter of ≥10 mm on CT or MRI according to RECIST 1.1, with mRECIST assessment performed when applicable * Availability of baseline and follow-up clinical and radiological data * Willing and able to provide written informed consent Exclusion Criteria: * Presence of another active malignancy, except for malignancies that have been curatively treated and remain recurrence-free * Prior systemic treatment with immune checkpoint inhibitors or anti-angiogenic agents for unresectable or advanced HCC * Expected inability to complete the required clinical or radiological follow-up assessments * Severe comorbid conditions that may interfere with study participation * No qualified residual blood sample available for planned biomarker analyses because of insufficient volume, contamination, loss, or other sample-related issues * Any condition deemed unsuitable for participation by the investigator