Pharmacogenetics of colorectal cancer in a third-level hospital in Valencia

Abstract

Abstract Objectives Genetic variants with associated pharmacokinetic and pharmacodynamic effects have an impact on the development of adverse drug reactions and survival of patients with colorectal cancer. Methods A selection of genetic variants was performed according to the established chemotherapy and the pharmacogenetic databases. Genotyping was performed using MassArray technology (Agena Bioscience). Variant-toxicity and survival-genotype correlations were assessed using logistic regression (SPSS v.28.0.1.1). Results Genotyping of 25 SNPs was performed in 96 patients. In relation to the DPYD gene, 3.5 % had the rs75017182 mutation; 4.7 % the rs1801158 mutation and 7.1 % the rs1801160 mutation. Genotypic frequencies in the UGT1A1 gene were 39.4 % (*1/*1); 37.9 % (*1/*28); 19.7 % (*28/*28); and 3 % (*1/*36). The genotypes CT of the rs1801160 variant, AT of the rs67376798 variant (DPYD) and *1/*36 (UGT1A1) were associated with low survival (p-value: 0.006, <0.001, and 0.052, respectively). The most frequent adverse reactions were gastrointestinal disorders, followed by neurotoxicity. The CC genotype (rs1801160, DPYD) was associated with a lower risk for developing severe gastrointestinal events, whereas CC (rs1801158, DPYD) was associated with a lower risk of developing severe general hematologic toxicity. Conclusions The population frequencies obtained in our study for rs1801160 and rs75017182 (DPYD); and for *1/*28, *28/*, and *1/*36 (UGT1A1) were inconsistent with the frequencies reported for the Spanish population in the literature. The genotypes CT of rs1801160, AT of rs67376798 (DPYD), and 1/*36 (UGT1A1) were associated with lower survival rates.