Search

Background: The multidrug resistance gene 1 (MDR1) encodes P-glycoprotein (P-gp), which plays an important role in mediating multidrug resistance to chemotherapeutic agents. MDR1 gene polymorphisms may have an impact on the expression and function of P-gp, thereby influencing the response to chemotherapy., Objectives: To investigate whether the MDR1 2677 and 3435 genotypes are associated with the sensitivity of non-small-cell lung cancer (NSCLC) to docetaxel., Methods: In this study we investigated the potential association of MDR1 2677G>T at exon 21, 3435C>T at exon 26 and their haplotypes with chemotherapy response of 54 Han Chinese patients with NSCLC. The patients were treated with docetaxel-cisplatin., Results: The 2677 GG genotype was associated with a significantly better response to chemotherapy compared with the combined 2677 GT and TT genotype (p = 0.035). The 3435 CC genotype was also associated with a better response to chemotherapy compared with the combined 3435 CT and TT genotypes although the difference was not statistically significant (p = 0.123). Moreover, patients harboring the 2677G-3435C haplotype had a statistically significant better response to chemotherapy compared with those with the other haplotypes combined (p = 0.015)., Conclusion: Our findings suggest that the MDR1 2677G>T/A polymorphism and the 2677G-3435C haplotype are predictors of treatment response to docetaxel-cisplatin chemotherapy in NSCLC patients., (Copyright 2008 S. Karger AG, Basel.)

Background: The polymorphisms of genes participate in metabolism and transport, and therefore may have an impact on the response to vinorelbine., Objectives: To investigate whether genotypes of CYP3A5, MDR1 and cyclooxygenase-2 (COX-2) are associated with the response to vinorelbine in non-small cell lung cancers (NSCLC)., Methods: We determined the genotypes of CYP3A5(*3), MDR1 (2677G-->T at exon 21 and 3435C-->T at exon 26 and their haplotypes) and COX-2 (-1195G-->A) polymorphisms by PCR-RFLP and chemotherapy response in 69 Chinese Han patients with NSCLC who received a combination chemotherapy of vinorelbine-cisplatin (VC). The chi(2) test was used to investigate potential associations between genotypes and response to chemotherapy. Odds ratios and 95% confidence intervals were calculated., Results: The 3435 CC genotype was associated with a significantly better chemotherapy response compared with the combined 3435 CT and TT genotypes (p = 0.025). The 2677 GG genotype was also associated with a better chemotherapy response compared with the combined 2677 GT and TT genotype, although it was not statistically significant. Moreover, we analyzed the haplotypes of MDR1 3435-2677: patients harboring the 2677G-3435C haplotype had a statistically significantly better response to chemotherapy compared with those with the other haplotypes combined (p = 0.015). CYP3A5*3 is not likely to correlate with sensitivity to vinorelbine in NSCLC. COX-2 (-1195G) is likely to result in a better response to vinorelbine (nonsignificant)., Conclusions: Our findings suggest that MDR1 2677G-->T/A and 3435C-->T polymorphisms can be used to predict treatment response to VC chemotherapy in NSCLC patients., ((c) 2007 S. Karger AG, Basel.)