MDR1 single nucleotide polymorphisms predict response to vinorelbine-based chemotherapy in patients with non-small cell lung cancer.

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.