In the present multi-center cooperative phase II study, in which 16 institutions participated, PJ-203 and mitomycin C were concomitantly infused into the hepatic artery of patients with metastatic liver cancer and the tumor response and safety of the combined therapy were examined. Of 81 patients treated with PJ-203, 52 patients were complete cases in which bidimensionally measurable lesions could be assessed for anticancer effect in accordance with the Direct Evaluation Criteria of Chemotherapy. The number of treatments given to the complete cases until the assessment of therapeutic effect ranged from 1 to 11 times, with the mean of 3.1 times. The overall response rate was 48.1% (25/52). The response rate for each primary lesion was 68.8% (11/16) for stomach cancer, 40.7% (11/27) for colorectal cancer and 33.3% (3/9) for other types of cancer including the gallbladder. The 25 patients with CR or PR, a 50% decrease in tumor size was confirmed after the treatment ranged from 1 to 5 times, with the treatment periods of 2 to 3 weeks. Adverse reactions were found in 56 (69.1%) out of 81 patients assessed for safety. Relatively frequent symptoms were pain in 49.4% (40/81), nausea and vomiting in 33.3% (27/81), fever in 30.9% (25/81) and anorexia in 6.2% (5/81). Principal abnormal laboratory values included a transient elevation of GOT (26.3%), GPT (22.5%), LDH (12.7%) and Al-p (8.8%). Blockade of blood flow could be observed by angiography when the amount of PJ-203 infused was in the range from 180 to 900 mg as degradable starch microspheres. The blood flow blockade could be observed most frequently at the amount of 600 mg (37.7%). The period attaining over 50% of tumor response in 25 complete cases was 42 days as a median. After the treatment was initiated in 81 patients, 50% survival duration and one-year survival rate averaged 277 days and 35.7%, respectively. The corresponding figures for each primary cancer were 419 days and 51.0% for patients with liver cancer metastasized from colorectal cancer, against 239 days and 11.8% for those with liver cancer metastasized from stomach cancer.