Prevalence of environmental and genetic risk factors for gastric cancer in a popu

胃癌(GC)可以被认为是健康差距的一个指标，因为它在 死亡率较高的发展中国家。在墨西哥，GC是第三大致死原因，仅次于 心血管疾病和肺癌，在美国，西班牙裔的胃癌发病率也高于美国白人。这个 胃癌的病因包括幽门螺杆菌感染、饮食因素和遗传易感性。由于 居住在德克萨斯州的大量MA儿童，以及#年观察到的胃病的高发病率 我们正在进行的研究：暴露在环境中的移民/季节性遗传易感性的生物标志物 农场工人儿童(MSF研究)，我们建议使用分子和环境流行病学 评估上述胃癌危险因素在这一少数群体中的流行率的方法。在……里面 此外，我们将开发和验证FFQ来评估MA儿童的叶酸和维生素B-12的摄入量 居住在德克萨斯州。我们的短期目标是估计社会问题的流行程度， 与MA儿童的GC风险相关的环境和遗传因素， 降低可通过预防性干预措施改变的风险的长期目标。这个 这项研究的具体目标是：1.从500个MA中生成流行病学和饮食GC风险数据 5至18岁的儿童。我们将获得社会经济和饮食信息，GC的家族史和 胃功能障碍(GD)、儿童病史和通过结构化双语获得的GD症状 采用间接访谈技术对母亲和孩子的参与者进行问卷调查。2：a型 参与叶酸-DNA甲基化的关键基因是胃癌风险的中间生物标志物。我们会 亚甲基四氢叶酸还原酶(MTHFR)基因在儿童中的多态性 由于该基因的变异性会严重影响叶酸的分布和可利用性， 这反过来又会增加GC的风险。3：测定叶酸、维生素B-12和同型半胱氨酸 孩子们的水平。我们将分析红细胞中的叶酸水平和体内的同型半胱氨酸水平 儿童参与者的血浆作为GC风险的中间生物标记物，因为叶酸缺乏可导致 同型半胱氨酸的积累，这反过来又减少了DNA所需的甲基的可用性 甲基化4.测定幽门螺杆菌抗体的血清阳性率。我们将分析这名患者的血清。 儿童参与者Hp抗体的存在，这是Hp暴露的一个指标，以及 胃癌的危险因素。识别儿童的能力是GC的风险，这要么是由于遗传易感性，要么是因为 环境因素对癌症预防具有重要意义。我们的研究结果可能 还有助于减少全球和美国现有的GC健康差距。

Gastric cancer (GC) can be considered an indicator of health disparity since it is more prevalent in developing countries, where the mortality is higher. In Mexico GC is the 3rd leading cause of mortality after CVD and lung cancer, and in the US, GC incidence is also higher in Hispanics than in white Americans. The etiologic factors for GC include Helicobacter Pylori infection, dietary factors and genetic susceptibility. Due to the large number of MA children residing in Texas, and the high prevalence of gastric disorders observed in our on-going study "Biomarkers of Genetic Susceptibility in Environmentally Exposed Migrant/Seasonal Farmworker Children (MSF Study), we propose to use a molecular and environmental epidemiologic approach to assess the prevalence of the aforementioned GC risk factors among this minority population. In addition, we will develop and validate a FFQ to assess the folate and vitamin B-12 intake of MA children residing in Texas. Our short-term goal is to estimate the magnitude of the prevalence of the social, environmental and genetic factors that have been associated with GC risk among MA children, with the long-term goal of reducing the risk that can be modified through preventive interventions. The specific aims of the study are to: 1. Generate epidemiological and dietary GC risk data from 500 MA children ages 5 to 18. We will obtain socioeconomic and dietary information, family history of GC and gastric disorders (GD), children's medical history and symptoms of GD via a structured bilingual questionnaire using indirect interviewing techniques with the mother and child participants. 2: Genotype a key gene involved in folate-DNA methylation as an intermediate biomarker for GC risk. We will genotype the children for polymorphisms in the methylenetetrahydrofolate reductase (MTHFR gene at position 677C>T since variability in this gene can critically influence the distribution and availability of folate, which in turn can increase the risk for GC. 3: Determine the folate, vitamin B-12 and homocysteine levels of the children. We will analyze the levels of folate in the erythrocytes and the homocysteine in the plasma of the children participants as intermediate biomarkers for GC risk since folate deficiency can lead to an accumulation of homocysteine, which in turn reduces the availability of methyl groups needed for DNA methylation 4. Determine the seroprevalence of antibodies against HP. We will analyze the serum of the children participants for the presence of IgG antibody against HP, which is an indicator of HP exposure, and a risk factor for GC. The ability to identify children are risk for GC, due to either genetic predisposition or environmental factors has substantial implication for cancer prevention. Findings from our study may also serve to reduce existent GC health disparities worldwide and in the U.S.