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