Polymorphisms of key chemokine genes and survival of non-small cell lung cancer in Chinese

Abstract

Chemokines play an important role in the pathogenesis of non-small cell lung cancer (NSCLC). Although the deregulations of chemokines have been reported to be associated with the development and progression of many human cancers including lung cancer, polymorphisms of chemokine genes have not been examined with the survival of NSCLC. We systematically investigated associations of 23 common potentially functional SNPs in the key chemokine genes (CCL2, CCL5, CCL8, CCL20, CCL22, CXCL1, CXCL6, CXCL9 and CXCL12) with the survival of NSCLC in a case cohort of 568 NSCLC patients in a Chinese population. The results showed that variant genotypes of CCL2 rs3760396 and CCL8 rs3138035 were associated with a significantly decreased risk of death for NSCLC (dominant model: adjusted HR=0.65, 95% CI=0.48-0.89 for rs3760396; dominant model: adjusted HR=0.65, 95% CI=0.49-0.86 for rs3138035), while CXCL12 rs1804429 was associated with an increased risk of death for NSCLC (CC vs AA: adjusted HR=6.03, 95% CI=1.44-25.24). Further stepwise regression analysis suggested that only rs3138035, a SNP located at 5'-flanking region of CCL8, was an independently favorable factor for the prognosis of NSCLC and the protective effect was more evident in smokers (adjusted HR=0.61, 95% CI=0.42-0.87), patients with squamous cell cancer (adjusted HR=0.58, 95% CI=0.35-0.96), patients with early stage (adjusted HR=0.32, 95% CI=0.15-0.67) and patients treated with surgical operation (adjusted HR=0.47, 95% CI=0.31-0.71). In addition, the interaction analysis demonstrated that stage and surgical operation interacted with the genetic effect of rs3138035 in relation to NSCLC survival (adjusted P(interaction)=0.02 and 0.01, respectively). These findings suggest that CCL8 rs3138035 may be one of the candidate biomarkers for NSCLC survival and may modify death risk associated with stage and surgical operation. Larger studies incorporating functional evaluations are warranted to validate our findings.