We discuss a life-threatening case of capecitabine toxicity due to the presence of a heterozygous variant on exon 14 (c.1905+1G>A, rs3918290) of the dihydropyrimidine dehydrogenase gene (DPYD). We advocate the need for dihydropyrimidine dehydrogenase deficit screening, which could become mandatory in Belgium, as in France, before any fluoropyrimidine administration to avoid cases of foreseeable toxicity.

(BELG J MED ONCOL 2020;14(4):151–4)