5-FU TOXICITY (DPYD MUTATIONS)

Background

5-Fluorouracil (5-FU) is one of the most commonly prescribed anti-cancer agents and used for a wide variety of malignancies, including colorectal, gastric, pancreatic, head, neck, breast, ovarian, and cervical cancers.
Dihydropyrimidine dehydrogenase (DPYD) is a key enzyme in the breakdown of 5-FU, and DPYD deficiency is an important determinant for severe adverse reactions from 5-FU treatment. Individuals with diminished DPYD activity cannot effectively inactivate 5-FU, which leads to toxic levels of 5-FU and to severe-to-lethal hematological, gastrointestinal, or neurological reactions, including stomatitis, diarrhea, dermatitis, fever, leukopenia, therombocytopenia, myelosuppression, and even death.
More than 40 mutations in the gene that codes for DPYD have been described and the most common three of them (DPYD*2A, p.I560S, p.D949V) account for more than 50% of the patients with a complete or nearly complete DPD deficiency.

Indications for testing

Estimation of individual risk for 5-FU toxicity

Analysis of the molecular cause for previous 5-FU toxicities

Factors other than DPYD mutation can influence drug response. A negative result (no mutant DPYD allele detected) on this test does not completely exclude toxicities in patients treated with 5-FU.

How can a DPYD gene analysis be requested?

To request a gene analysis, simply send an EDTA blood tube with the completed request form to the Renner laboratory. It is not necessary to refrigerate the sample. The result of the genetic analysis will be sent to you within a few days.

Specimen Shipping

Literature:

Morel A et al. Clinical relevance of different dihydropyrimidine dehydrogenase gene single nucleotide polymorphisms on 5-fluorouracil tolerance. Mol Cancer Ther. 2006;5:2895-904.