UGT1A1 IRINOTECAN TOXICITY

General Information

HLAB/HOL Code: UGT1A
UPHSM LIS Test #: 026637
Schedule:
Testing Time: 5-7 Days
Testing Lab: Labcorp

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 5.0 mL whole blood or a buccal swab kit
Temperature: Ambient
Tube Type: Whole blood or Labcorp buccal swab kit
Collection Info:
Minimum Volume: 3 mL whole blood or two buccal swabs
Container: Lavender-top (EDTA) tube, yellow-top (ACD) tube, or LabCorp buccal swab kit
Collection: Whole blood preferred. Collect specimen in a lavender-top (EDTA) or yellow-top (ACD) tube, or use a buccal swab kit. Ship whole blood specimen at room temperature or frozen. Ship buccal swab collection kit at room temperature.

Specimen Acceptability

Cause for Rejection:
Hemolysis; quantity not sufficient for analysis; improper container; single buccal swab; wet buccal swab

Methods

Polymerase chain reaction (PCR); capillary electrophoresis


Clinical Utilities

Irinotecan (Camptosar®) is used, or under evaluation, in a broad spectrum of solid tumors, and is often prescribed for treating patients with metastatic cancer of the colon or rectum, especially when 5-fluorouracil treatment has not been entirely successful. Severe toxicity (eg, grade 4 neutropenia) is commonly observed in cancer patients receiving irinotecan who carry the UGT1A1*28 allele, also called TA. This test result will provide valuable information to physicians prior to initiating or modifying treatment or supplementing treatment with additional drugs. UGT1A1 variants have also been reported in patients with disorders of bilirubin metabolism, such as Crigler-Najjar Types I and II, as well as Gilbert syndrome. Between 80% to 100% of Caucasian patients with Gilbert syndrome are reported to have either one or two copies of UGT1A1*28. G71R (*6), a UGT1A1 variant reported in Asian patients with Gilbert syndrome, is not detected by this assay.
Limitations:  The current test will only test the TATA box polymorphism of the UGT1A1 gene. The other polymorphisms of this gene will not be detected.

CPT Codes

81350

* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.