Integrating the oral fluoropyrimidines into the management of advanced colorectal cancer

In colorectal cancer, leucovorin-modulated 5-fluorouracil (5-FU) has been the mainstay. of both adjuvant treatment and treatment of metastatic disease for many years. In advanced disease. response rates of 10-43% are reported: efforts to improve efficacy through schedule modification. including prolonged infusions, have led to limited success. New agents with improved efficacy. tolerability and ease of administration are required. Among thr newer drugs, irinotecan and oxaliplatin are becoming established as first- and second-line treatment for advanced disease. Their novel mechanisms of action have proven to be of value in 5-FU-resistant patients. In tandem with these developments, thymidylate synthase inhibition has remained an important objective rind oral fluoropyrimidines such as capecitabine and UFT (uracil plus tegafur)/leucovorin have been developed viith this goal in mind. Two large. phase III studies of capecitabine in metastatic disease demonstrated objective response rates of 26.6 and 24.8%. UFT leucovorin has also been evaluated in phase III trials. with an 11.7% response rate reported. Both agents are being evaluated in combination with oxaliplatin and irinotecan, and ultimately oral fluoropyrimidines as monotherapy or combination therapy may. replace intravenous (i.v.) 5-FU as first-line treatment for metastatic colorectal cancer. (C) 2001 Elsevier Science Ltd. All rights reserved.