UGT1A1 Irinotecan Toxicity

Casandra

Casandra Test Code LC05129Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 511200CPT Code 81350

UGT1A1 Irinotecan Toxicity

Also known as: Camptosar®, Irinotecan

Clinical Use

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Use

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.

Special Instructions

Testing involves the detection of the TATA box polymorphism of the UGT1A1 gene only. Whole blood is preferred as a specimen type, but a LabCorp buccal swab kit is also acceptable. Whole blood specimens should be shipped at room temperature or frozen, and buccal swabs at room temperature. Ensure accurate documentation of specimen requirements, including proper container usage and volume limits.

Limitations

The test exclusively detects variants at the TATA box polymorphism of the UGT1A1 gene, specifically the (TA)5, (TA)6, (TA)7, and (TA)8 alleles. Other polymorphisms in the UGT1A1 gene will not be detected. Additionally, the G71R (*6) variant, which is significant in Asian patients with Gilbert syndrome, is not detected by this assay. This test has not been cleared or approved by the FDA.

Test Details