Selective anticancer effects of 3',5'-dioctanoyl-5-fluoro-2'-deoxyuridine, a lipophilic prodrug of 5-fluoro-2'-deoxyuridine, dissolved in an oily lymphographic agent on hepatic cancer of rabbits bearing VX-2 tumor.

3',5'-Dioctanoyl-5-fluoro-2'-deoxyuridine (FdUrd-C8), one of the lipophilic prodrugs of 5-fluoro-2'-deoxyuridine (FdUrd) was dissolved in an oily lymphographic agent (Lipiodol Ultra-Fluid), which had been studied as a carrier of the anticancer drug for hepatic cancer. The prodrug was administered into the left proper hepatic artery of rabbits bearing VX-2 tumor in the liver in order to examine the anticancer effects and possible adverse effects on nontumorous hepatic cells. Lipiodol or FdUrd-C8*Lipiodol selectively remained in the hepatic cancer area but disappeared from nontumorous parts of the liver 7 days after injection. Tumor growth rates in 1 week of the untreated group, a group given injections of 0.2 ml of Lipiodol alone, and groups given injections of 0.2 ml of Lipiodol containing 30, 50, 70, and 100 mg of FdUrd-C8 were 636, 436, 34.8, 14.9, -2.4, and -10.4% of the size at the time of treatment, respectively. Pathological observation also showed that FdUrd-C8 had a strong anticancer effect on VX-2 tumor growing in the liver of the rabbits. In contrast to the effect on the cancerous cells, that on nontumorous hepatic cells was very slight. In pathological observation, necrosis or degeneration of nontumorous hepatic cells was hardly observed. Plasma glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase levels temporarily rose 1 day after injection but returned to the initial levels within 7 days in all groups.