Statistical analysis
Statistical analysis was done using Stata Version 16.0. Continuous variables, such as age, dose and BMI were presented as medians and interquartile ranges (IQR). Qualitative variables, such as cancer stage, performance status and co-medications were presented as numbers and percentages. Hardy–Weinberg equilibrium of variants and genotype distribution were tested by χ2 (p > 0.05). The association of DIC and the variants was evaluated using Pearson Chi-Square exact test. We also tested the association of UGT1A6 rs17863783, SLC28A3 rs7853758 and RARG rs2229774 with cardiotoxicity using logistic regression adjusted for age at start of treatment, cumulative anthracycline dose and BMI. Statistical significance was set at p< 0.05.