Association of cytidine deaminase and xeroderma pigmentosum group D polymorphisms with response, toxicity, and survival in cisplatin/gemcitabine- treated advanced non-small cell lung cancer patients

Background: Selecting patients according to key genetic characteristics may help to tailor chemotherapy and optimize the treatment in non-small cell lung cancer (NSCLC). Genetic variations in drug metabolism may affect the clinical response, toxicity, and prognosis of NSCLC patients treated with cisplatin/gemcitabine-based therapy. PATIENTS AND Methods: We evaluated seven single-nucleotide polymorphisms of six genes CDA Lys27Gln (A/C); CDA C435T; ERCC1 C118T; XRCC3 Thr241Met (C/T); XPD Lys751Gln (A/C); P53 Arg72Pro (G/C), and RRM1 C524T in 192 chemotherapy-naive patients with advanced NSCLC treated with cisplatin/gemcitabine-based regimen by TaqMan probe-based assays with 7300 Real-Time PCR System, using genomic DNA extracted from blood samples. Results: The CDA 435 T/T genotype was significantly associated with better response (p = 0.03). The CDA 435 C/T genotype was associated with a significantly increased risk of nonhematological toxicity of grade 3 (p = 0.02) after adjusting for performance status, age, and type of treatment regimen. In the multivariate Cox model, the XPD 751 C/C genotype was a significant prognostic factor of longer progression-free survival (p = 0.006). Conclusion: Our data suggest polymorphic variations of drug metabolic gene were associated with response and toxicity of cisplatin/gemcitabine-based therapy and progression-free survival of patients with advanced NSCLC.