Sho-Saiko-To Following Removal of Liver Cancer By Embolization in Treating Patients With Liver Cancer That Cannot Be Surgically Removed

DISEASE CHARACTERISTICS: One of the following conditions: Histologically confirmed unresectable hepatocellular carcinoma Serum alpha-fetoprotein (AFP) level greater than 500 ng/mL with cirrhosis Serum AFP level greater than 500 ng/mL with a liver mass and positive hepatitis B or C serology Receiving ablation therapy with embolization Extrahepatic disease allowed No brain metastases PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 1,500/mm^3 Platelet count greater than 50,000/mm^3 Hemoglobin greater than 8.0 g/dL Hepatic: See Disease Characteristics Bilirubin less than 2.0 mg/dL SGOT or SGPT less than 5 times upper limit of normal (ULN) PT or INR less than 1.6 times ULN (if not receiving warfarin for anticoagulation) Albumin greater than 2.5 g/dL Renal: Creatinine less than 1.8 mg/dL Pulmonary: DLCO at least 50% predicted OR DLCO at least 70% predicted if total lung capacity less than 80% predicted No significant lung disease Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix No uncontrolled infection or pain No other condition that would significantly impair cognitive functioning during the study No overt psychosis, mental disability, or other incompetency that would preclude study No other life-threatening illness for which the prognosis is poorer than for hepatocellular carcinoma PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent interferon Chemotherapy: No prior chemotherapy within 4 weeks of initiating ablation therapy No concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy within 4 weeks of initiating ablation therapy Concurrent radiotherapy allowed Surgery: See Disease Characteristics Other: See Disease Characteristics No prior ablation therapy No other concurrent Sho-saiko-to or any of its constituent plants No other concurrent anticancer medications