Phase II Study of Fluoropyrimidine Dose Adjustment Based on DPD Enzyme Levels in Adults With Gastrointestinal Cancers

What this Trial Is About

Researchers are studying how to adjust the dose of fluoropyrimidine chemotherapy based on uracilemia levels in patients with DPD deficiency who have gastrointestinal cancers. This phase II multicenter trial aims to find the best dose reduction strategy to reduce side effects while treating digestive cancers. The main question is which dose reduction is needed for patients with this enzyme deficiency. Participants will receive chemotherapy with doses adjusted according to their uracilemia level. Patients with low uracilemia <16 ngmL will get the full dose, while those with higher levels will receive varying dose reductions or random assignments between 25% and 50% reductions depending on their uracilemia range. Treatments include the FOLFOX or CAPOX chemotherapy regimens, given in cycles every 2 to 3 weeks. During the study, participants will visit the clinic every 2 to 3 weeks for checkups and tests to monitor side effects and treatment response. Researchers will measure the occurrence of serious blood and gastrointestinal toxicities after two treatment cycles and track dose adjustments, toxicity, and survival outcomes over several months and years. The study involves close monitoring of health and treatment effects for up to three years, depending on cancer stage.

Dose Individualization of Chemotherapy in Patients With Gastrointestinal Cancers Lacking a Specific Liver Enzyme