Aims: Validation of associations for SNPs in RAC2, NCF4 and SLC28A3, identification of a novel association with a TOP2B SNP and screening 23 SNPs putatively relevant to anthracycline-induced cardiotoxicity.
Patients & methods: A total of 166 breast cancer patients treated with doxorubicin underwent echocardiogram, including 19 cases with systolic dysfunction (ejection fraction <55%) and 147 controls. Four high priority SNPs were tested in the primary analysis, with appropriate statistical correction, and 23 additional SNPs were screened in an uncorrected secondary analysis.
Results: Previously reported associations for RAC2, NCF4 and SLC28A3 could not be validated and a novel association with TOP2B was not discovered in this cohort (all p > 0.05), likely due to inadequate power. Two SNPs were identified in the uncorrected secondary analysis including a protective SNP in ABCB1 (3435C>T, p = 0.049) and a risk allele in CBR3 (V244M, p = 0.012).
Conclusion: The associations reported in prior publications and those discovered in this secondary analysis require further replication in independent cohorts.
Keywords: ABCB1; CBR3; NCF4; RAC2; SLC28A3; TOP2B; anthracycline; cardiotoxicity; doxorubicin; pharmacogenetic; systolic dysfunction.