According to news from The Mayo Clinic, a genetic screening test that can determine which patients are likely to have a serious adverse reaction to Camptosar® (irinotecan hydrochloride), a key component of standard first-line therapy for advanced colon and rectal cancers. An article at http://www.emaxhealth.com/51/4752.html describes the details.
According to Mayo Clinic medical oncologist Matthew Goetz, M.D. who was quoted in the article, "Irinotecan is an important treatment approved by the FDA for patients with colon and rectal cancers, but its side effects can be dangerous or even lethal in up to 30 percent of the population." The UGT1A1 test--which looks for a mutation in the gene that helps a patient metabolize irinotecan, was approved by the FDA in August; licensing agreements have just been finalized. If a patient has the mutated gene, dosing of irinotecan would have to be reduced or even eliminated to avoid serious side effects.
According to the article, "This kind of customized dosing approach based on a person's genetic makeup is known as pharmacogenomics and is the newest frontier of 21st century medicine." Dr. Goetz adds that the application of this test for patients with colon and rectal cancer may only be the beginning. "Irinotecan also is being tested and used for other cancers, such as cancers of the GI tract, as well as lung and breast carcinoma,"
Because the UGT1A1 pathway is also important in the metabolism of other drugs, the test may be useful for managing potentially serious side effects of some other drugs also. The test kits are available from the Mayo Clinic, through your physician or other healthcare provider. The test is not being sold directly to consumers.
Marie Godfrey, PhD
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