DPYD genotyping and 5-fluoropyrimidine toxicity: An overview of systematic reviews protocol.

INTRODUCTION: The increased risk of severe and life-threatening toxicity in patients with dihydropyridine dehydrogenase deficiency, under treatment with fluoropyrimidines, has been widely studied. An up-to-date overview of systematic reviews summarizing existing literature can add value by highlighting most relevant information and supports decision-making regarding treatment in dihydropyridine dehydrogenase deficient patients. The main objective of this overview is to identify published systematic reviews on the association between germline variations in the DPYD gene and fluoropyrimidine toxicity.

METHODS AND ANALYSIS: This protocol was developed following the Preferred Reported Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) checklist, and the overview of systematic reviews will be reported in accordance with the PRISMA statement. PubMed, Embase, Scopus and the Cochrane Library will be searched from inception to 2023. Systematic reviews irrespective of study designs that analyze the association between germline variations in the DPYD and fluoropyrimidine toxicity will be considered. Methodological quality will be assessed using AMSTAR2 checklist (Measurement Tool to Assess Systematic Reviews 2). Two independent investigators will perform the study selection, quality assessment and data collection. Discrepancies will be solved by a third investigator.