Arsenic Trioxide in Treating Patients With Metastatic Liver Cancer That Cannot Be Removed by Surgery

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed hepatocellular carcinoma * Unresectable metastatic disease * Ascites allowed provided it is minimal PATIENT CHARACTERISTICS: Age * Over 18 Performance status * 0-2 Life expectancy * Not specified Hematopoietic * WBC \> 2,500/mm\^3 * Absolute neutrophil count \> 1,500/mm\^3 * Platelet count \> 75,000/mm\^3 Hepatic * Bilirubin \< 2.5 mg/dL * AST \< 2.5 times upper limit of normal Renal * Not specified Cardiovascular * QTc interval ≤ 460 msec AND potassium and magnesium normal Other * Not pregnant or nursing * Negative pregnancy test * Fertile female patients must use effective double-method contraception for ≥ 4 weeks before, during, and for ≥ 4 weeks after completion of study treatment (during and for ≥ 4 weeks after completion of study treatment for male patients) * No blood, ova, or sperm donation during study treatment * Potassium \> 4.0 mEq/dL * Magnesium \> 1.8 mg/dL PRIOR CONCURRENT THERAPY: Biologic therapy * No concurrent biologic therapy Chemotherapy * More than 4 weeks since prior and no other concurrent chemotherapy Endocrine therapy * Not specified Radiotherapy * More than 4 weeks since prior and no concurrent radiotherapy Surgery * Not specified Other * No other concurrent investigational agents