Matrix metalloproteinase-2 polymorphisms and clinical outcome of Chinese patients with nonsmall cell lung cancer treated with first-line, platinum-based chemotherapy.

BACKGROUND

Matrix metalloproteinase-2 (MMP-2) is well known for its critical role in cell survival and cancer development. It also plays an important role in hematopoietic recovery after chemotherapy-induced myelosuppression. In this study, the authors investigated the association of MMP-2 polymorphisms with treatment efficacy and the occurrence of severe toxicity in patients with nonsmall cell lung cancer (NSCLC) who were receiving first-line, platinum-based chemotherapy.

METHODS

A pharmacogenetic association study was performed in 663 Chinese patients who had inoperable stage III/IV NSCLC and were receiving first-line, platinum-based regimens. Information about objective response, progression-free survival, overall survival, grade 3 or 4 gastrointestinal toxicity (nausea/vomiting), and hematologic toxicity (neutropenia, anemia, thrombocytopenia) was available. Sixteen tag single nucleotide polymorphisms (SNPs) of MMP-2 were assessed.

RESULTS

In 7 polymorphisms, significant associations were observed with the incidence of grade 3 or 4 neutropenia. The variant homozygotes of reference SNP rs12934241 exhibited the most significant effect on the risk of neutropenia, leading to an incidence rate that increased from 12.3% (for the C/C genotype) to 50% (for the T/T genotype; odds ratio, 8.33; P = 8.8 × 10(-5)). Stratified analyses indicated that rs12934241 exhibited a much stronger influence in the cisplatin-gemcitabine regimen subgroup than subgroups that received other regimens (P(interaction) = .003). Further haplotype analyses produced results that were consistent with results from single-SNP analyses. However, no significant association was observed between MMP-2 polymorphisms and treatment efficacy, including response rate, clinical benefit, progression-free survival, and overall survival.

CONCLUSIONS

To the authors' knowledge, this study provides the first evidence for a predictive role of MMP-2 polymorphisms in the variability of severe chemotherapy-related neutropenia among Chinese patients with platinum-treated, advanced NSCLC.