C609T Polymorphism of NADPH Quinone Oxidoreductase 1 Correlates Clinical Hematological Toxicities in Lung Cancer Patients Treated with Amrubicin

BACKGROUND: Amrubicin hydrochloride (AMR) is a key agent for lung cancer. NADPH quinone oxidoreductase 1 (NQO1) metabolizes the quinone structures contained in both amrubicin (AMR) and amrubicinol (AMR-OH). We hypothesized that NQO1 C609T polymorphism may affect AMR-related pharmacokinetics and clinical outcomes. METHODS: Patients received AMR doses of 30 or 40 mg/m(2)/day on days 1–3. Plasma sampling was performed 24 hours after the first and third AMR injections. Concentrations of AMR and AMR-OH were determined by HPLC and the NQO1 C609T polymorphism was assayed by RT-PCR. RESULTS: A total of 35 patients were enrolled. At a dose of 40 mg/m(2), the T/T genotype exhibited a tendency toward a relationship with decrease concentrations of AMR-OH on days 2 and 4. The genotype also showed a significant decrease of hematological toxicities (P < 0.05). CONCLUSIONS: NQO1 C609T polymorphism had a tendency of correlation with the plasma concentrations of AMR-OH, and thereby had significant correlations with hematologic toxicities.