Providing more theoretical basis for the prediction of the efficacy of advanced HCC and helping select better advantaged population of HCC immunotherapy to maximize the benefits of patients By exploring the relationship between the changes of PD-1 expression in peripheral blood T lymphocytes and the clinical efficacy before and after the use of PD-1 / PD-L1 inhibitors.

Exploring the expression of peripheral blood T lymphocyte PD-1 from an immunological perspective as a potential reference marker for selecting immunotherapy in advanced HCC patients, and elucidating the relationship between the level of peripheral blood T lymphocyte PD-1 expression and survival outcomes after receiving immunotherapy. Additionally, investigating whether there is consistency between the expression levels of PD-1 and PD-L1 and their impact on patients. Furthermore, exploring the correlation between the distribution of T cell subsets and the efficacy of immunotherapy to provide new theoretical evidence for the selection of target populations for immunotherapy and new clinical screening indicators for patient prognosis assessment.

Inclusion Criteria:

• Willing to participate in the clinical study, fully understand and be informed about the study, and sign the informed consent form;
• Age between 18 and 75 years, male or female;
• Strictly meet the clinical diagnostic criteria for hepatocellular carcinoma (HCC), confirmed by histology or cytology, with at least one lesion meeting the RECIST 1.1 criteria on CT or MRI examination;
• No prior targeted therapy, immunotherapy, or systemic chemotherapy for liver cancer before admission;
• Child-Pugh A liver function; Barcelona Clinic Liver Cancer (BCLC) stage B or C;
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1;
• Normal function of major organs;
• Expected survival time of at least 12 weeks or more.

Exclusion Criteria:

• Patients who have not previously received treatment with Sintilimab or any other PD-L1 or PD-1 antagonist;
• Patients with any active autoimmune disease or a history of autoimmune disease, or a history of immunodeficiency;
• Patients requiring the use of immunosuppressive drugs;
• Known history of allergy to the formulation of Sintilimab or any other component of the antibody formulation;
• Patients with other malignant tumors.