Q: How common is 5-FU toxicity?
A: As many as 1 in 3 patients receiving 5-FU related therapy experience dose-limiting toxicity that is largely avoidable.
Q: What is the prevalence of clinically significant DPYD and TYMS variants?
A: Up to 25% (1/4) of individuals have variations in the DPYD and/or TYMS genes that are associated with an increased risk of toxicity to 5-FU.
Q: What is the risk of toxicity due to DPYD and TYMS variations?
A: Variations in the DPYD and TYMS genes are associated with up to a 60% risk of dose-limiting toxicity to 5-FU or capecitabine therapy.
Q: Who is a candidate for the TheraGuide 5-FU™ test?
A: Any patient for whom 5-FU/capecitabine therapy is being considered is a candidate for TheraGuide 5-FU™. There is a tremendous benefit to the patient for determining toxicity risk prior to starting 5-FU chemotherapy, or at the beginning of his or her regimen. By assessing the risk of 5-FU toxicity, oncologists can identify patients who may not effectively metabolize 5-FU/capecitabine and thereby, provide enhanced therapeutic choices for improved patient outcomes.
Q: Are there any formal recommendations for testing for DPD deficiency?
A: While there are no formal recommendations that specifically address testing for DPD deficiency, the FDA does have a statement on its Web site that reads:
"The U.S. Food and Drug Administration reported in its March 2003 Safety Labeling Changes Approved by FDA Center for Drug Evaluation and Research (CDER) that Xeloda® (capecitabine) is contraindicated in patients who have a known dihydropyrimidine dehydrogenase (DPD) deficiency." (http://www.fda.gov/medwatch/SAFETY/2003/mar03.htm). This warning appears in the Xeloda® package insert. Additionally, the manufacturers of 5-fluorouracil (5-FU) have issued warnings and/or contraindications for patients with DPD enzyme deficiency. Please refer to the current Xeloda® and appropriate 5-fluorouracil (5-FU) package inserts for complete prescribing and safety information.
Q: How is the TheraGuide 5-FU™ test performed?
A: TheraGuide 5-FU™ is a blood test that detects variations in the DPYD and TYMS genes in order to predict the patient's risk for 5-FU toxicity. Sample requirements are 7 mL of blood collected in a lavender-top EDTA tube which is then sent to Myriad Genetic Laboratories at ambient temperature. A sample kit can be ordered at www.myriadtests.com or by contacting your Customer Service Specialist at 1-800-469-7423.
Q: Why is TheraGuide 5-FU™ unique?
A: TheraGuide 5-FU™ testing by Myriad is the most comprehensive clinically available test for assessing the risk of 5-FU toxicity caused by these genes and is the only diagnostic test offering full sequencing of DPYD, as well as analysis of the TYMS gene.
Q: Is TheraGuide 5-FU™ clinically validated?
A. Yes, the results are clinically validated and performed in our CLIA-certified laboratory.
Q: How do I order TheraGuide 5-FU™?
A: This is a simple blood test. The TheraGuide 5-FU™ test kit will have a test request form and sample checklist for further details. A complimentary test kit can be ordered at www.myriadtests.com or by contacting your Customer Service Specialist at 1-800-469-7423.
Q: How much is the TheraGuide 5-FU™ test?
A: TheraGuide 5-FU™ is the most comprehensive test available for assessing the risk of 5-FU toxicity caused by variations in the DPYD and TYMS genes. It employs the full sequencing of the DPYD gene and analysis of the TYMS gene. The price of the test is $1,100.
Q: Is TheraGuide 5-FU™ covered by insurance?
A: As with our other tests, we expect to have excellent insurance coverage over time. As with any new service, we may request a Letter of Medical Necessity or other assistance to secure reimbursement. For additional information, lease see our Patient Protection Plan.
Q: Do I need to provide ICD-9 codes?
A: Our reimbursement specialists require accurate ICD-9 codes to aid with their health insurance billing and reimbursement activities. There is an "Ancestry & Clinical History" section with a subheading called "What Kind of Cancer Does This Patient Have?" on the TRF where physicians must enter a listing of ICD-9 code(s). This section is required to be completed by all ordering HCPs in order to begin test processing. Please contact the Myriad Customer Service at 1-800-469-7423 for additional information.
Q: What is the turnaround time for the TheraGuide 5-FU™ test?
A: The expected turnaround time for TheraGuide 5-FU™ results is 7 days after receipt, provided the test request form included with the blood specimen is filled out completely, including billing option information with the blood sample. (Insurance billing requires patient signature and readable [enlarged] copy of both sides of insurance card[s]. If 2 cards are submitted, indicate which is primary.)
