Helicobacter pylori and cytokine gene variants as predictors of premalignant gastric lesions

Abstract

Gastric cancer remains the third leading cause of mortality from cancer worldwide and carries a poor prognosis, due largely to late diagnosis. The importance of the interaction between Helicobacter pylori (H. pylori) infection, the main risk factor, and host-related genetic factors has been studied intensively in recent years. The genetic predisposition for non-hereditary gastric cancer is difficult to assess, as neither the real prevalence of premalignant gastric lesions in various populations nor the environmental risk factors for cancer progression are clearly defined. For non-cardiac intestinal-type cancer, identifying the factors that modulate the progression from inflammation toward cancer is crucial in order to develop preventive strategies. The role of cytokines and their gene variants has been questioned in regard to non-self-limiting H. pylori gastritis and its evolution to gastric atrophy and intestinal metaplasia; the literature now includes various and non-conclusive results on this topic. The influence of the majority of cytokine single nucleotide polymorphisms has been investigated for gastric cancer but not for preneoplastic gastric lesions. Among the investigated gene variants onlyIL10T-819C, IL-8-251, IL-18RAP917997, IL-22 rs1179251, IL1-B-511, IL1-B-3954, IL4R-398 and IL1RN were identified as predictors for premalignant gastric lesions risk. One of the most important limiting factors is the inhomogeneity of the studies (e.g., the lack of data on concomitant H. pylori infection, methods used to assess preneoplastic lesions, and source population). Testing the modifying effect of H. pylori infection upon the relationship between cytokine gene variants and premalignant gastric lesions, or even testing the interaction between H. pylori and cytokine gene variants in multivariable models adjusted for potential covariates, could increase generalizability of results.

Keywords: Gastritis; Gene variants; Glandular atrophy; Helicobacter pylori; Interleukins; Intestinal metaplasia; Premalignant; Single-nuclear polymorphism.