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Dose Adjusted Fluoropyrimidine to Reduce Toxicity for Patients with Heterozygous DPYD Deficiency Receiving 5-Fluorouracil or Capecitabine for Cancer Treatment

Trial Status: active

This phase II trial tests how well giving a reduced dose of fluoropyrimidine works to reduce side effects for patients with heterozygous DPYD deficiency who are receiving 5-fluorouracil or capecitabine for cancer treatment. Fluoropyrimidines, like 5-fluorouracil (5-FU) and capecitabine, are common chemotherapy drugs used for many cancers. However, the amount of the drug that causes side effects can vary greatly among patients. A small number of patients experience severe, sometimes life-threatening, side effects because they have a deficiency in an enzyme called dihydropyrimidine dehydrogenase (DPYD). This enzyme is made by the DPYD gene and helps break down 5-FU into less harmful substances. Giving a reduced dose of fluoropyrimidines may work to reduce side effects for patients with heterozygous DPYD deficiency who are receiving 5-fluorouracil or capecitabine for cancer treatment.