PHASE-II TRIAL OF 5-FLUOROURACIL, FOLINIC ACID, AND N,N-1,N-11-TRIETHYLENETHIOPHOSPHORAMIDE (THIOTEPA) IN PATIENTS WITH ADVANCED BREAST-CANCER

A total of 35 women with advanced, metastatic breast cancer were treat ed with combination chemotherapy consisting of folinic acid 500 mg/m(2 ) over 2 hours administered with 600 mg/m(2) of 5FU at the midpoint of the folinic acid infusion weekly for 6 weeks, plus 60 mg/m(2) of thio tepa on day 1 and day 28. The cycle was repeated every 8 weeks. Patien ts were evaluated for toxicity weekly. Response was evaluated at the e nd of each 8-week cycle. The median age was 55 years (range: 34-67). P rior to this study 30 patients had received chemotherapy; 13 had 1 reg imen; 17 had 2 or more regimens; 8 had 5FU treatment; 18 had hormonal therapy; and 15 had radiation treatment. The overall response rate was 40% (1 complete and 13 partial); median duration of response was 4 mo nths. Four of 8 patients with prior 5FU responded. Hematologic toxicit y was significant: nadir WBC count: <1,000/mm(3) (10 patients); 1,000- 1,999/mm(3) (13 patients); nadir platelet count: <20,000/mm(3) (8 pati ents); 20,000-49,000/mm(3) (8 patients); 50,000-99,000/mm(3) (10 patie nts). We conclude that the combination of thiotepa, 5FU, and leucovori n has significant myelotoxicity and do not recommend its routine use i n the treatment of metastatic breast cancer. Key Words: Metastatic bre ast cancer-SFU-Folinic acid-Thiotepa-Chemotherapy-Phase II.