The cancer anorexia/weight loss syndrome: exploring associations with single nucleotide polymorphisms (SNPs) of inflammatory cytokines in patients with non-small cell lung cancer

The cancer anorexia/weight loss syndrome commonly occurs in patients with non-small cell lung cancer (NSCLC) and is characterized by loss of weight and appetite as well as diminished survival. The current study explored whether any of 22 single nucleotide polymorphisms (SNPs) of certain previously implicated inflammatory cytokines (interleukin-1 beta, interleukin-1RN, interleukin-6, and tumor necrosis factor) are associated with this syndrome. All NSCLC patients who had been enrolled in the Mayo Clinic Lung Cancer Cohort, had completed a health-related questionnaire approximately 6 months after enrollment, and had blood drawn were included in this study, thus yielding a sample size of 471 patients. Sixty-six (14%) patients manifested weight loss shortly after diagnosis, and 152 (32%) reported appetite loss. Only tumor necrosis factor alpha rs800629 was associated with anorexia (odds ratio: 0.46; 95% confidence interval: 0.29, 0.72; p < 0.001); patients who were heterozygous and minor homozygous were less likely to suffer anorexia. Otherwise, there were no statistically significant associations between any of the other 21 SNPs and weight loss and/or anorexia. In univariate analyses, weight loss, anorexia, more advanced cancer stage, and interleukin-1 beta rs1143627 were associated with a worse survival, and interleukin-6 rs2069835 was associated with better survival. However, in multivariate analyses, cancer stage and patient age were the only statistically significant predictors of worse survival. No specific SNP was associated with all aspects of the cancer anorexia/weight loss syndrome, but rs800629 may merit further study in cancer-associated anorexia.