IL18 and metastatic malignant neoplasm in the lymph nodes: Patients with G/C alleles IL-18 -137G/C polymorphism showed a decreased risk of developing Stages III-IV (AOR=0.59; 95% CI=0.39-0.89; p=0.01), a tumor size > T2 (AOR=0.56; 95% CI=0.35-0.87; p=0.01), and lymph node metastasis (AOR=0.51; 95% CI=0.32-0.80; p=0.003).