Comparison of treatment of metastatic gastrointestinal cancer with 5-fluorouracil (5-FU) to a combination of 5-FU with cytosine arabinoside

Abstract

Patients with inoperable adenocarcinoma of the gastrointestinal tract were randomly treated with either 5-fluorouracil (5-FU) at an initial dose of 15 mg/kg/week IV with a placebo subcutaneously once a week (group I) or with cytosine arabinoside 30 mg/m2/week subcutaneously (group II). When an initial evaluation showed no apparent difference in toxicity or antitumor effect between the two regimens, the cytosine arabinoside was given at a dose of 100 mg/m2/week IV (group III). There were 69 patients treated with Regimen I, 70 with Regimen II, and 16 with Regimen III, with an overall response rate of 20.3, 20 and 25%, respectively. The duration of responses was often brief with a median duration of 3 months for Regimens I and III and 2.5 months for Regimen II. All three regimens were well tolerated. Two toxic deaths occurred in patients treated with Regimen II. The study confirmed that weekly IV 5-FU has roughly similar antitumor efficacy as the “standard” method of 5-FU treatment but at much less cost in toxicity. It also demonstrated lack of potentiation of the antitumor action of 5-FU by cytosine arabinoside in the manner it was administered.