Gene Test Could Save Patients With Cancer From Fluorouracil “Overdose”

KFF Health News (3/26, Allen) reports more than 275,000 patients with cancer in the US “are infused each year with fluorouracil, known as 5-FU, or...take a nearly identical drug in pill form called capecitabine. These common types of chemotherapy are no picnic for anyone, but for patients who are deficient in an enzyme that metabolizes the drugs, they can be torturous or deadly.” In these cases, “patients essentially overdose because the drugs stay in the body for hours rather than being quickly metabolized and excreted.” However, “a recent survey found that only 3% of U.S. oncologists routinely order the tests before dosing patients with 5-FU or capecitabine.” This is “because the most widely followed U.S. cancer treatment guidelines – issued by the National Comprehensive Cancer Network – don’t recommend preemptive testing.” Now, “the FDA added new warnings about the lethal risks of 5-FU to the drug’s label on March 21 following queries from KFF Health News about its policy,” but “it did not require doctors to administer the test before prescribing the chemotherapy.”