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Which factors can induce gastric cancer in China?

Half of gastric cancer is in China. First of all, there is a genetic susceptibility. That is to say, the previous generation has gastric cancer, and the next generation is more likely to have gastric cancer. The Chinese are the most likely to get gastric cancer. So what factors will lead to gastric cancer? Which people are the most likely to get gastric cancer? Let's have a look.

More than 70% of gastric cancer is asymptomatic in the early stage, but only in the middle and late stage can the corresponding symptoms be caused by epigastric pain, gastrointestinal bleeding, perforation, pyloric obstruction, emaciation, fatigue, metabolic disorder and cancer spread and metastasis, which can occur at any age, most of them are 50-60 years old, and the ratio of male to female is 3:1.

So, what factors are gastric cancer related to?

Regional environment and dietary factors

There are obvious regional differences in the incidence of gastric cancer. The incidence of gastric cancer in the coastal areas of northwest and East China is significantly higher than that in the south.

Why is there obvious regional difference in the incidence of gastric cancer? The study found that the trend of high incidence areas of gastric cancer in China is from the northwest, along the Hexi Corridor, Gansu, Shaanxi, Shanxi, Inner Mongolia, then eastward to Liaoning, and then down the coastline to Shandong Peninsula, Anhui, Zhejiang to Fujian. The residents in the northwest and east coastal areas mainly eat meat, like smoked, roasted or even pickled pork, mutton, etc. These eating habits are exactly the cause of gastric cancer. In these foods, nitrite, mycotoxin, polycyclic aromatic hydrocarbons and other carcinogens or pre carcinogens are high, leading to the incidence of gastric cancer is also gradually increasing. This is the case of Huang in case 1.

1. Helicobacter pylori infection

HP infection rate of adults in the high incidence area of gastric cancer in China is more than 60%. Helicobacter pylori can promote the transformation of nitrate into nitrite and nitrosamine and cause cancer. HP causes chronic inflammation of gastric mucosa and environmental factors accelerate the over proliferation of mucosal epithelial cells, leading to aberrant carcinogenesis.

CagA and VacA, the toxic products of Helicobacter pylori, may play a role in promoting cancer. The detection rate of anti CagA antibody in gastric cancer patients is significantly higher than that in the general population. In case 2, Zhang and case 3, Wang were all positive for H. pylori, suggesting that H. pylori is a high risk factor.

3. Precancerous lesions

Gastric polyps, chronic atrophic gastritis and remnant stomach after partial gastrectomy may be accompanied by chronic inflammatory process, metaplasia or atypical hyperplasia of intestinal epithelium of gastric mucosa, and may be transformed into cancer.

Gastric cancer does not change from normal cells to cancer cells in a single step, but a multi-step process of carcinogenesis, that is, chronic superficial gastritis rarr; atrophic gastritis rarr; intestinal metaplasia rarr; dysplasia rarr; gastric cancer. The lesions in this period are called precancerous lesions. The 10-year canceration rate of mild dysplasia was 2.5% - 11%, moderate dysplasia was 4% - 35%, and severe dysplasia was 10% - 83%. Wang of the three cases, 15 years ago, performed gastroscopy in the outpatient department of our hospital to detect gastric polyps and biopsy to detect adenomatous polyps. Adenomatous polyp is a common precancerous lesion with the possibility of canceration.

4. Genetics and genes

The carcinogenesis of gastric cancer involves the changes of oncogene, tumor suppressor gene, apoptosis related gene and metastasis related gene, and the forms of gene changes are also diverse. Gastric cancer patients have obvious familial aggregation. The survey found that the risk of gastric cancer in the first-degree relatives of patients with gastric cancer was three times higher than that in the general population. In case 2, Zhang, whose grandfather died of gastric cancer, was diagnosed with gastric cancer by his father five years ago, suggesting that genetic risk factors.

5. According to the investigation of long-term smoking and drinking, the risk of gastric cancer in long-term smokers is 50% higher than that in non-smokers. Nicotine in tobacco can directly stimulate the gastric mucosa, destroy the barrier of gastric mucosa, promote the formation of gastritis and gastric ulcer, delay its healing, and further lead to malignant transformation. Drinking alcohol can cause the stomach to suffer from the malignant stimulation of alcohol, which is easy to cause the chronic inflammation of the stomach, and then make the gastric mucosa proliferate seriously, and finally lead to the occurrence of gastric cancer. In case 1, Huang and case 4, sun had similar situation, suggesting that smoking and drinking were high risk factors.

6. The investigation of mental depression shows that depression, sadness, missing, loneliness, depression, hatred, disgust, inferiority, self reproach, guilt, interpersonal tension, mental breakdown, and sulking can significantly increase the risk of gastric cancer. However, those who are cheerful, optimistic and lively have the lowest risk. Sun in case 4 is similar, suggesting that mental depression is a high risk factor.