tokens: From October 1993 to November 1995 , we treated 13 patients with previously chemotherapy - treated metastatic breast cancer by mitoxantrone , 12 mg / m2 , on day 1 and continuous infusion of 5 - FU , 3000 mg / m2 , together with leucovorin , 300 mg / m2 , for 48 h from day 1 to 2 .