Since patients with high levels of IL-6 in circulation presented worse overall and event-free survival compared to those with low levels, it was also observed that 43.3% of patients with low levels of this cytokine had a GC or CC genotype, despite the fact that this association was not significant (p = 0.07), this may be due probably to the reduced sample size, multiple factors related to the patient’s condition at the time the sample was obtained, or factors associated with the characteristics of malignancy of the tumor. This evidence concerns the gene IL6 and neoplasm.