Test Details
Methodology
Polymerase chain reaction (PCR); capillary electrophoresis
Result Turnaround Time
5 - 7 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
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.
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.
This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).
References
Specimen Requirements
Specimen
Whole blood or LabCorp buccal swab kit (buccal swab collection kit contains instructions for use of a buccal swab)
Volume
5 mL whole blood or LabCorp buccal swab kit
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 Instructions
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.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | Whole blood: 7 days; buccal swab: 6 months |
Refrigerated | Whole blood: 1 month |
Frozen | Whole blood: 2 years |
Storage Instructions
Maintain whole blood specimen at room temperature for 7 days or refrigerated for 1 month, or frozen for 2 years. Maintain buccal swabs at room temperature for 6 months.
Causes for Rejection
Hemolysis; quantity not sufficient for analysis; improper container; single buccal swab; wet buccal swab
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 511200 | UGT1A1 Irinotecan Toxicity | 41044-9 | 511202 | Result: | 41044-9 | |
| 511200 | UGT1A1 Irinotecan Toxicity | 41044-9 | 511224 | Additional Information: | N/A | |
| 511200 | UGT1A1 Irinotecan Toxicity | 41044-9 | 511208 | Director Review: | 72486-4 | |
| 511200 | UGT1A1 Irinotecan Toxicity | 41044-9 | 000000 | MGRM Informed Consent Review | N/A | |
| Order Code | 511200 | |||||
| Order Code Name | UGT1A1 Irinotecan Toxicity | |||||
| Order Loinc | 41044-9 | |||||
| Result Code | 511202 | |||||
| Result Code Name | Result: | |||||
| UofM | ||||||
| Result LOINC | 41044-9 | |||||
| Order Code | 511200 | |||||
| Order Code Name | UGT1A1 Irinotecan Toxicity | |||||
| Order Loinc | 41044-9 | |||||
| Result Code | 511224 | |||||
| Result Code Name | Additional Information: | |||||
| UofM | ||||||
| Result LOINC | N/A | |||||
| Order Code | 511200 | |||||
| Order Code Name | UGT1A1 Irinotecan Toxicity | |||||
| Order Loinc | 41044-9 | |||||
| Result Code | 511208 | |||||
| Result Code Name | Director Review: | |||||
| UofM | ||||||
| Result LOINC | 72486-4 | |||||
| Order Code | 511200 | |||||
| Order Code Name | UGT1A1 Irinotecan Toxicity | |||||
| Order Loinc | 41044-9 | |||||
| Result Code | 000000 | |||||
| Result Code Name | MGRM Informed Consent Review | |||||
| UofM | ||||||
| Result LOINC | N/A |