RESEARCH COMMUNICATION Influence of MDR1 Gene Codon 3435 Polymorphisms on Outcome of Platinum-based Chemotherapy for Advanced Non Small Cell Lung Cancer

Mortality of lung cancer is higher than any other cancer type globally (Jemal et al., 2009). Approximately 85% of lung cancer patients would be reclassified as non small cell lung cancer (NSCLC), and 70% these patients could be further diagnosed with advanced NSCLC (Lustberg et al., 2007; Li et al., 2011). Platinum-based doublet chemotherapy was considered as the standard treatment for patients with advanced NSCLC based on several large clinical trials, with longer survival time and better quality of life comparing with other regimens (Grilli et al., 1993; Souquet et al, 1993; Marino et al, 1994; Obasaju et al., 2009). However, according to previous report, among oriental patients with advanced NSCLC treated with platinumbased chemotherapy, the response rate is around 19%, and many of these patients would experience disease progression (Schiller et al, 2002; Yao et al, 2009; Li et al, 2011). Previous studies suggested that such chemotherapy failure was related to multi-drug resistance (MDR), which might be influenced by MDR1 gene single nucleotide polymorphisms (SNPs) (Gottesman et al, 2002; Illmer et al, 2002; Oselin et al, 2003; Woodahl et al, 2004; Sohn et al., 2006). Among a total of 50 SNPs and 3