BACKGROUND: Studies have demonstrated that some polymorphisms in diff erent interleukin genes may increase the risk of cancer. The aim of this study was to investigate the association between the IL-8 (rs4073) -251A/T gene polymorphism and the risk of gastric cancer (GC). PATIENTS AND METHODS: A case-control study was conducted on patients with noncardia gastric cancer. DNA was extracted from leukocytes and the IL-8 (rs4073) -251A/T polymorphism was analyzed by PCR-RFLP. Infection with Helicobacter pylori was investigated in the serum by ELISA. RESULTS: The sample consisted of 104 patients with GC and 196 controls. Cigarette smoking (P=0.007) and high fat intake (P=0.01) were more frequent in patients with GC.

The multidrug resistance 1 (MDR1) gene encodes P-glycoprotein, which confers resistance to antineoplastic drugs, but also affects the kinetic disposition of certain drugs and carcinogens. The C3435T polymorphism of the MDR1 gene may influence the transport and excretion of carcinogens, increasing the risk of cancer. The aim of this study was to evaluate the association between this polymorphism and the risk of gastric cancer (GC). Ninety-eight patients with non-cardia GC and 203 healthy subjects participated in the study. DNA was extracted from leukocytes and the MDR1 polymorphism was analyzed using PCR-RFLP. Serology was performed by ELISA for the investigation of infection with Helicobacter pylori. No significant difference in the genotype (p=0.668) or allele (p=0.745) frequency of the C3435T polymorphism was observed between the GC and control groups. There was no association between the genotypes studied and the risk of GC in patients infected with H. pylori (p=0.662). Patient survival was not correlated with the genotypes studied (p=0.454). No correlation was observed between the C3435T polymorphism of the MDR1 gene and GC risk or prognosis in the population studied.