MITOXANTRONE, LEUCOVORIN AND HIGH-DOSE INFUSIONAL 5-FLUOROURACIL - AN EFFECTIVE AND WELL-TOLERATED REGIMEN FOR THE TREATMENT OF ADVANCED BREAST-CANCER

Mitoxantrone and 5-fluorouracil (5-FU) are active drugs with a favourable toxicity profile in advanced breast cancer. The activity of 5-FU can be enhanced by modulation with leucovorin. Continuous infusion of S-FU yields a superior activity with less toxicity compared with bolus injections. 27 patients with advanced breast cancer, 22 of them pretreated, received intravenous (iv) mitoxantrone, 14 mg/m2, day 1, iv leucovorin, 300 mg, days 1 and 15, and 5-FU, 4 g, 48-h infusion, days 1 and 2, 15 and 16, once every 28 days (MLF regimen). Leucovorin was administered either as a bolus prior to the 5-FU infusion or mixed together with the 5-FU during the first 24 h. There were 12 partial responses, 9 patients had stable disease, and 5 had progressive disease. 1 patient was not evaluable because of concomitant irradiation of the target lesion. The overall response rate was 46%; for previously untreated patients it was 100% and for pretreated patients it was 33%. Grade 3 nausea/vomiting was noted in 7 evaluable patients (26%) and grade 4 haematological toxicity in 1 patient (4%). Only 1 patient had complete alopecia. The median duration of response was 13 months in untreated, and 12 months in pretreated patients. It was concluded that MLF is an active regimen in advanced breast cancer, even in highly pretreated patients, with moderate and manageable toxicity. Assessment in first-line treatment appears to be of interest.