Genetic Variants Influence the Severity of Oral Mucositis in Pediatric Osteosarcoma Patients.

BACKGROUND: The variability in patients' risk of oral mucositis (OM) has been, in part, attributed to differences in host genomics. The aim better define the role of genomics as an OM risk by investigating the association between genetic variants and the presence and severity of OM in pediatric patients with osteosarcoma (OS) undergoing chemotherapy (CT). METHODS: A longitudinal observational retrospective study was conducted. Severity of OM was assessed daily using World Health Organization (WHO) criteria. Blood samples were collected, and DNA was extracted. 54 coding regions were analyzed for 17 candidate genes using next-generation sequencing. RESULTS: A total of 164 CT cycles were evaluated in 14 pediatric patients being treated for OS with HDMTX (66.9%) and doxorubicin + cisplatin (34.1%). OM was diagnosed in 129 cycles (78.7%). Whereas the presence of OM was associated with ABCA3 (rs13332514) in HDMTX cycles, OM severity was associated with ABCC2 (rs2273697) in multivariate analysis. In doxorubicin + cisplatin, genetic variants of ABC family genes (ABCC2 and ABCC6) were associated with OM in multivariate analysis. CONCLUSION: Oral mucositis risk and severity in a pediatric population being treated for OS with HDMTX, doxorubicin, and cisplatin were associated with genes in the ABC family (ABCA3, ABCC2, and ABCC6 genes).