Screening for dihydropyrimidine dehydrogenase deficiency: to do or not to do, that's the question.

The treatment of cancer patients with 5-fluorouracil (5FU)-based chemotherapy can be accompanied by severe and sometimes lethal toxicity. Dihydropyrimidine dehydrogenase (DPD) plays a pivotal role in the metabolism of 5FU and as such, a deficiency of DPD has been recognized as an important risk factor, predisposing patients to the development of severe 5FU-associated toxicity. To date, screening of patients for the presence of a DPD deficiency prior to the treatment is not yet routinely performed. Taking into account the relatively small impact of adjuvant 5FU-based chemotherapy on survival, patients should be informed about the risks of the therapy and should be offered the possibility of testing for the presence of a DPD deficiency in advance of receiving such treatment.