TREATMENT OF PREVIOUSLY TREATED METASTATIC BREAST-CANCER BY MITOXANTRONE AND 48-HOUR CONTINUOUS-INFUSION OF HIGH-DOSE 5-FU AND LEUCOVORIN (MFL) - LOW PALLIATIVE BENEFIT AND HIGH TREATMENT-RELATED TOXICITY

For previously treated advanced breast cancer, there is no standard se cond-line therapy, Combination chemotherapy with mitoxantrone, high-do se 5-fluorouracil (5-FU) and leucovorin (MFL regimen) had been reporte d as an effective and well tolerated regimen, From October 1993 to Nov ember 1995, we treated 13 patients with previously chemotherapy-treate d metastatic breast cancer by mitoxantrone, 12 mg/m(2), on day 1 and c ontinuous infusion of 5-FU, 3000 mg/m(2), together with leucovorin, 30 0 mg/m(2), for 48 h from day 1 to 2. Each course of chemotherapy was g iven every 4 weeks, Most of these patients had more than two metastati c sites, with lung metastasis predominant, Seven patients had been tre ated with anthracycline. Seven patients had previously received radiot herapy and seven had received hormone therapy, Median number of course s of MFL regimen given was six and the median cumulative dose of mitox antrone was 68.35 mg/m(2). One patient had complete response, seven ha d stable disease, none had partial response and five had progressive d isease, The overall objective response rate was 7.6%. The median follo w-up period was 14 months, Median survival was 16 months, Median progr ession-free survival was 5 months. A complete responder had relapse-fr ee survival up to 17 months, Major toxicities were cardiotoxicity and leukopenia. Eight patients were dead in the last follow-up; two of the m died of treatment-related toxicity, The MFL regimen achieves little palliative benefit and induces severe toxicity at a fairly high rate, Administration of this regimen to breast cancer patients who have been treated by chemotherapy and those with impaired heart function requir es careful attention.