ORAL 5-FU ANALOGS IN THE TREATMENT OF BREAST-CANCER

Three oral 5-fluorouracil (5-FU) therapies have been approved by the U S Food and DI ng Administration or are in development for the treatmen t of patients with breast cancer: capecitabine, UFT, and 5-FU/enilurac il. Capecitabine has been approved for breast cancer patients whose di sease is paclitaxel-resistant, and either anthracycline-resistant or f or whom further anthracycline use in not indicated A response rate of 20% was observed in an open-label phase II trial of capecitabine in he avily pretreated patients with metastatic breast cancer Diarrhea and h and-foot syndrome were the most frequently reported toxicities. In a r andomized phase II study of capecitabine vs paclitaxel in breast cance r patients who had failed anthracyclines, response rates were 36% for capecitabine vs 21% for paclitaxel, Several phase II trials of 5-FU/en iluracil in breast cancer are ongoing, Preliminary response data from one of these trials on 31 patients with anthracycline- and taxane-resi stant advanced breast cancer showed a 16% partial response rate, Grade 3-4 treatment-related toxicities included diarrhea (8%), nausea (3%), and granulocytopenia (3%). In Japan, UFT is widely used for the treat ment of breast cancer in both the adjuvant and metastatic settings, th rough studies in the United Stares are just getting under way, A phase II trial conducted in Madrid, Spain evaluated the combination of UFT, methotrexate, and leucovorin as salvage therapy for breast cancer pat ients. The overall response rate was 38% among 21 patients, and diarrh ea was the most common toxicity, Many questions remain unanswered abou t the optimal use of oral 5-FU agents in breast cancer. There seems li ttle question that these agents have substantial activity and will fin d a glace in the therapeutic armamentarium.