Current status of oral chemotherapy for colorectal cancer

The treatment of advanced colorectal cancer over the past 4 decades has required the use of intravenous chemotherapy, most typically fluorouracil (5-FU). The possibility of providing an alternative to intravenous delivery while at the same time improving the quality of life of patients who require fluorouracil for advanced or adjuvant therapy has provided the stimulus for the development of oral fluoropyrimidine drugs. Five oral fluoropyrimidine drugs have recently entered clinical trials in the United States. These include capecitabine (Xeloda), UFT (uracil and tegafur) or UFT/leucovorin (Orzel), eniluracil (ethynyluracil), S-1, and BOF A-2. At least two of these drugs have demonstrated survival equivalent to the standard intravenous fluorouracil and leucovorin regimens used to treat advanced colorectal cancer. This, together with less severe toxicity and potential increased quality of life, should lead to approval of one or more of these oral agents in the near future. Based on both patient and physician acceptance of oral fluoropyrimidines, other oral drugs from classes other than fluoropyrimidines will likely be developed in the near future.