带你详细了解胃癌的发病原因！

    印度代购温馨提示，1.地域环境及饮食生活要素

　　胃癌发病有明显的地域性差异，在我国的西北与东部沿海地域胃癌发病率比南方地域明显为高。长期食用熏烤、盐腌食品的人群中胃远端癌发病率高，与食品中亚硝酸盐、真菌毒素、多环芳烃化合物等致癌物或前致癌物含量高有关;吸烟者的胃癌发病风险较不吸烟者高50%。

There are obvious regional differences in the incidence of gastric cancer. The incidence of gastric cancer in northwest and eastern coastal regions of China is significantly higher than that in southern regions. The incidence of distal gastric cancer in people who eat smoked and salted food for a long time is high, which is related to the high content of carcinogens or precarcinogens such as nitrite, mycotoxins and polycyclic aromatic hydrocarbons in food. Smokers have a 50 percent higher risk of stomach cancer than non-smokers.

　　印度代购温馨提示，2.幽门螺杆菌(Hp)感染

　　我国胃癌高发区成人Hp感染率在60%以上。幽门螺杆菌能促使硝酸盐转化成亚硝酸盐及亚硝胺而致癌;Hp感染惹起胃黏膜慢性炎症加上环境致病要素加速黏膜上皮细胞的过度增殖，招致畸变致癌;幽门螺杆菌的毒性产物CagA、VacA可能具有促癌作用，胃癌患者中抗CagA抗体检出率较普通人群明显为高。

　　印度代购温馨提示，3.癌前病变

　　胃疾病包括胃息肉、慢性萎缩性胃炎及胃局部切除后的残胃，这些病变都可能伴有不同水平的慢性炎症过程、胃黏膜肠上皮化生或非典型增生，有可能转变为癌。癌前病变系指容易发作癌变的胃黏膜病理组织学改动，是从良性上皮组织转变成癌过程中的接壤性病理变化。胃黏膜上皮的异型增生属于癌前病变，依据细胞的异型水平，可分为轻、中、重三度，重度异型增生与分化较好的早期胃癌有时很难辨别。

　　印度代购温馨提示，4.遗传和基因

　　遗传与分子生物学研讨标明，胃癌患者有血缘关系的亲属其胃癌发病率较对照组高4倍。胃癌的癌变是一个多要素、多步骤、多阶段开展过程，触及癌基因、抑癌基因、凋亡相关基因与转移相关基因等的改动，而基因改动的方式也是多种多样的。

Genetic and molecular biology studies have shown that the incidence of gastric cancer is 4 times higher in related relatives than in the control group. The carcinogenesis of gastric cancer is a multi-factor, multi-step and multi-stage development process, which involves the changes of oncogenes, tumor suppressor genes, apoptosis-related genes and metastasis-related genes, and the ways of gene changes are also diverse.