Association of interleukin-8 gene polymorphism with cachexia from patients with gastric cancer.

Interleukin (IL)-8 has been implicated in a wide range of diseases. The polymorphism of IL-8 gene, which may affect the production level of the cytokine, may be associated with cancer cachexia. To test this hypothesis, we investigated the potential influence of the polymorphisms of the IL-8 gene, -251 A/T and +781 C/T, on susceptibility to cachexia from patients with gastric cancer in a Chinese population, using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A significantly increased frequency of +781 T allele was noted in patients with cachexia (OR = 1.765, 95% CI: 1.192-2.615, P = 0.004). The +781 TT genotypes were observed to be associated with a significantly increased risk of cachexia (OR = 2.156, 95% CI: 1.056-4.400, P = 0.033), and the difference was enhanced beyond the level of statistical significance when logistic regression was applied (OR = 3.500, 95% CI: 1.406-8.710, P = 0.007). Haplotype analysis revealed that A(251)T(781) haplotype (defined by SNPs at positions -251 and +781) was associated with a significantly increased risk of cachexia as compared with the T(251)C(781) haplotype (OR = 1.69; 95% CI: 1.08-2.62; P = 0.022). These results suggest that the genetic polymorphisms of proinflammatory cytokine IL-8 may contribute to the pathogenesis of cachexia in gastric cancer patients.