Hepatic intra-arterial injection of lipiodol-1,25-dihydroxyvitamin D3 for hepatocellular carcinoma in rats

BACKGROUND: 1,25-(OH)2 D3 has an in vitro growth regulator effect on different cancers. Unfortunately, dose-limiting toxicity (hypercalcemia) limits its use in anticancer therapy. For primary liver tumors, loco-regional delivery of 1,25-(OH)2 D3 in lipiodol might avoid high systemic concentrations and development of hypercalcemia. MATERIALS AND METHODS: 1,25-(OH)2 D3 alone or mixed in lipiodol, was delivered at different concentrations into the hepatic artery of rats bearing a primary liver tumor. Calcium levels, tumor volume and proliferation index were assessed after treatment. RESULTS: Serum calcium values were significantly lower when the drug was mixed into lipiodol. Treatment with 10 micrograms of 1,25-(OH)2 D3 in ethanol resulted in a decrease in proliferation index within the tumor. CONCLUSIONS: The delivery of 1,25-(OH)2 D3 mixed in lipiodol reduces the subsequent elevation of serum calcium. Locoregional treatment with 1,25-(OH)2 D3 was shown for the first time to be effective on primary liver tumor growth in vivo.