The purpose of this study is to evaluate the safety and efficacy of hepatic arterial infusion chemotherapy (HAIC) in combination with PD-1 inhibitors and Lenvatinib in patients with high tumor burden advanced-stage hepatocellular carcinoma (HCC) with portal vein tumor thrombus (PVTT).

Inclusion Criteria:

1. Age 18 to 80 years old;
2. Diagnosis of HCC was confirmed by histologic or cytologic analysis or clinical features according to the American Association for the Study of Liver Diseases (AASLD) guideline;
3. At least one measurable intrahepatic lesion as per the RECIST 1.1 criteria;
4. HCC staging of the patients are consistent with both the BCLC stage C and the CNLC stage IIIa.
5. Presence of PVTT;
6. Patients received a first-line lenvatinib+PD-1 (L+P) inhibitors combination or that of HAIC+lenvatinib+PD-1 inhibitors (H+L+P). More specifically, the administration of lenvatinib was concomitant with PD-1 inhibitors, and HAIC was performed either concurrently with, or up to 2 months before or after the L+P inhibitors combination therapy. Patients in the H+L+P group should undergo at least 2 cycles of HAIC, receive at least 2 cycles of PD-1 inhibiors and take at least 2 months of lenvatinib. Patients in the L+P group should receive at least 2 cycles of PD-1 inhibiors, and take at least 2 months of lenvatinib.
7. Child-Pugh class A or B7;
8. Tumor burden meets up to 7 out criteria.

Exclusion Criteria:

1. Patients who took anti-tumor treatments before the combination therapy;
2. With other malignant tumors;
3. incomplete data.

Patients with high tumor burden advanced HCC with PVTT who received HAIC in combination with PD-1 inhibitors and Lenvatinib under real-world practice conditions.