Wen Wee Ma, MBBS

The fluoropyrimidine 5-fluorouracil (5-FU) and its prodrug capecitabine are cytotoxic agents that have been widely used in the treatment of solid tumors. In the United States alone, an estimated 275,000 patients with cancer receive 5-FU each year. Despite its lifesaving/life-prolonging potential, 5-FU causes severe early-onset toxicity in up to one-fourth of patients, and more than 1300 die each year as a result of this toxicity.