[Chemoembolization with degradable starch microspheres for liver metastases of colorectal cancer]

Transcatheter chemoembolization using degradable starch microspheres (DSM) was performed in 17 patients with liver metastases of colorectal cancer. DSM, 45 microns in diameter, which are easily degraded by serum amylase, and therefore obstruct arterial blood flow temporarily at the arteriolar capillary bed. DSM mixed with mitomycin C were administered through the catheter introduced by Seldinger's method in 13 cases, and through subcutaneously implanted drug delivery system (Port-A-Cath) in 4 cases. The treatment was repeated 5 times on the average at intervals of 2 to 4 weeks. The therapeutic effect of this chemoembolization was evaluated by the change in tumor size measured by angiography or computed tomography. Tumor regression of over 50% was observed in 9 of 17 cases (53%). Elevated serum CEA levels (greater than 10 ng/ml) decreased in 10 of 15 cases (67%). One-year survival rate was 48% in 17 cases, and among them it was 100% in 7 cases with the extent of several liver metastases (H2). Extrahepatic metastasis was observed in 3 of 17 cases (18%) before the treatment, and in 8 cases (47%) after the treatment. Abdominal pain occurred in 36% of the cases by the administration of DSM, but the pain disappeared within 2 hours. No major side effects such as bone marrow suppression or hepatotoxicity were observed. Our results suggest that chemoembolization using DSM is effective and safe in the treatment of liver metastases from colorectal cancer.