Association of IL-6 gene polymorphisms with cachexia susceptibility and survival time of patients with pancreatic cancer.

The purpose of this study was to determine the predictive value of IL-6-572, -190, and -634 gene polymorphisms on the cachexia susceptibility and survival time of patients with pancreatic cancer. Genotypes were determined using restriction fragment length polymorphism analysis of polymerase chain reaction products. All of the subjects were homozygous to the C allele of IL-6-190. No significant differences were found in the IL-6-572G and -190C distributions between the cachexia group and the non-cachexia group. Patients with cachexia showed significantly higher prevalence of common bile duct obstruction (CBD) than those without (p = 0.026). A significantly increased frequency of the IL-6-634G allele was noted in the cachexia group vs the non-cachexia group (p = 0.021). Logistic regression adjusted for sex, age, duodenal obstruction, and CBD obstruction, the IL-6-634 CG + GG genotype was associated with an odds ratio of 2.785 (1.034, 7.501) for cachexia. Patients with IL-6-634 CG + GG carrier showed shorter duration of survival than those with CC genotype (p = 0.023). These results indicate that the IL-6-634G allele is associated with increased susceptibility to cachexia and decreased survival time of Chinese patients suffering from pancreatic cancer.