Comparison of response to 5'-deoxy-5-fluorouridine therapy alone and in combination with tamoxifen or medroxyprogesterone acetate in advanced and recurrent breast-cancer.

We studied the therapeutic usefulness of low dose 5'-deoxy-5-fluorouridine (5'-DFUR) alone and in combination with medroxyprogesterone acetate (MPA) or tamoxifen (TAM). As first line therapy, 58 patients with advanced and recurrent breast cancer were assigned to receive Regimen A (5'-DFUR 600 mg/body/day daily + TAM 30 mg/body/day daily), Regimen B (5'-DFUR 600 mg/body/day daily + MPA 600 mg/body/day daily), or Regimen C (5'-DFUR 600 mg/body/day daily). In 48 evaluable patients, the response rates to treatment were 22.2% (4/18 cases) with Regimen A, 62.5% (10/16 cases) with Regimen B, and 21.4% (3/14 cases) with Regimen C. Regimen B was significantly superior to the other two regimens. The incidence of adverse reactions was low in all three groups, being 10.5% (2/19 cases) with Regimen A, 12.5% (2/16 cases) with Regimen B, and 21.4% (3/14 cases) with Regimen C. In addition, the degree of all adverse reactions was mild (WHO grade 1). Low dose 5'-DFUR therapy in combination with low dose MPA was evaluated to be a useful treatment regimen, emphasizing the quality of life of patients, based on its high effectiveness and safety in advanced and recurrent breast cancer patients.