Prostaglandin E1 enhances tumoricidal activity of 5-fluoro-2'-deoxyuridine in rats

Addition of prostaglandin E1 (PGE1) to 5-fluoro-2'-deoxyuridine (FUDR) infused via the portal vein has been shown to diminish both the regional and the systemic toxicity of this chemotherapeutic agent. The effect of concomitant PGE1 infusion on tumor growth has not yet been determined. This study was designed to assess the effect of PGE1 in combination with FUDR on an established adenocarcinoma in the rat model. Fifty-gram Fischer rats underwent placement of a 3-mm3 fragment of colon carcinoma 4047 in the left thigh pad. After 6 weeks to allow for tumor growth, the animals were randomly assigned to receive a 7-day intravenous infusion of (1) saline, (2) PGE1 (0.1 microgram/kg/min), (3) FUDR (3 mg/kg/day), or (4) PGE1 + FUDR. At 10 days animals receiving PGE1 + FUDR had a significant decrease in tumor volume (mm3, log 10) (3.39 +/- 0.24 vs 3.85 +/- 0.12, P less than 0.05) compared with animals receiving FUDR alone. We conclude that PGE1 may be useful as an adjunctive cytotoxic agent.