[A Case of Hepatocellular Carcinoma with Vp4 Tumor Thrombus Achieving Clinical CR Through Multimodality Treatment].

The patient is a 67-year-old male. His chief complaints were epigastric pain and abdominal distension. He had a history of hepatitis B and was referred to our hospital after an abdominal ultrasound at a nearby clinic detected a liver tumor. Contrast-enhanced CT revealed Vp4 hepatocellular carcinoma diffusely occupying the entire left lobe of the liver, accompanied by a tumor thrombus in the main portal vein. The tumor thrombus in the main portal vein was associated with a high risk of portal vein obstruction, so we initiated local radiotherapy(50 Gy/25 Fr)and anticoagulant therapy, followed by combination immunotherapy(atezolizumab+bevacizumab). After 7 courses, significant tumor shrinkage was achieved, and we planned a liver resection. However, during the drug-free period, tumor markers increased, and new lesions were detected in liver segment 5, leading us to abandon resection and resume combination immunotherapy. After 10 courses, the patient developed liver atrophy, ascites, splenomegaly, and thrombocytopenia. We continued treatment, stopping bevacizumab while administering diuretics and combining with CART, but treatment was halted due to the progression of liver cirrhosis. Four months after discontinuation of treatment, contrast-enhanced CT showed multiple early-enhancing lesions in liver segment 4, indicating recurrence. Blood flow in the left branch of the portal vein had resumed via collateral pathways, so we performed transcatheter arterial chemoembolization(TACE)twice. At 2 years and 4 months after starting treatment, tumor markers normalized, and at 3 years and 9 months after starting treatment, the patient maintained a state of clinical complete response(cCR).