• ALDH3A1*2 (rs2228100) → Hemorrhagic cystitis (OR = 11.95; 95% CI = 1.18–120.56; p = 0.04); liver toxicity (OR = 5.13; 95% CI = 1.30–20.30; p = 0.02)• ALDH3A1*2/*2 (rs2228100) → Haemorrhagic cystitis (OR = 9.08; 95% CI = 1.02–80.58; p = 0.05)• ALDH1A1*2 (rs8187996) → Liver toxicity grade 3–4 (OR = 5.13; 95% CI = 1.30–20.30; p = 0.02). Here, ALDH3A1 is linked to toxicity.