GENETIC POLYMORPHISMS OF GENES ENCODING DRUG METABOLISM ARE RELATED TO ORAL MUCOSITIS IN PEDIATRIC PATIENTS WITH CANCER

Objective: To investigate the incidence of oral mucositis (OM) in pediatric patients undergoing oncological treatment and their relationship with genetic polymorphisms of genes encoding chemotherapeutic drugs metabolism and transport. Study Design: DNA was isolated from whole blood of 89 pediatric patients with cancer who received treatment with methotrexate (MTX) and/or cyclophosphamide and/or doxorubicin. Next-generation sequencing (NGS) was performed using a customized panel of genes in the platform Ion Torrent PGM to analyze genetic polymorphisms of the ABCB1, ABCC2, and MTHFR genes. OM was assessed using the World Health Organization (WHO) scale. Results: Higher prevalence of severe OM was associated with 3 genetic polymorphisms of the ABCB1 gene (rs2235013 [P = .030], rs2235033 [P = .030], rs1128503 [P = .048]). Some genetic polymorphism of the ABCC2 and MTHFR genes were observed; however, there were no association with development of OM. Conclusion: Our findings showed that polymorphisms in the genes encoding ABCB1 substantially influence the OM development in pediatric patients with cancer. The understanding of genetic polymorphism of chemotherapeutic drugs can contribute to efficacy and safety of oncological treatment.