Epidemiology of gastric cancer

Gastric cancer is one of the most common cancers in Korea and has the highest mortality rate and has a very large impact on public health. The incidence of gastric cancer varies according to race, ethnicity, region, and social class. It is more common in lower social classes and is more common in men.
Gastric adenocarcinoma, which accounts for the majority of gastric cancer in Korea, accounts for 85% of all gastric cancers, and gastric lymphoma and leiomyosarcoma account for 15%.

Causes of stomach cancer

1) food

Burnt or salty foods are high in nitrates. These nitrates are converted to nitrites by bacteria, which increases the chances of causing cancer. Therefore, people who are more likely to eat food contaminated with bacteria are more likely to develop stomach cancer. In addition, those who have poor gastric acid secretion, have undergone gastrectomy, or have severe atrophic gastritis are more likely to develop stomach cancer because they are vulnerable to bacteria that change into carcinogens.

2) Helicobacter pylori

Although there is still controversy as to whether or not it is the direct cause of gastric cancer, it is argued that this fungus causes atrophic gastritis, lowering gastric acid secretion and increasing the likelihood of gastric cancer by causing intestinal epithelization of the gastric mucosa.

What is Helicobacter pylori?

Helicobacter pylori is an important cause of chronic gastritis and peptic ulcer recurrence and is a contagious bacterium associated with gastric cancer and gastric lymphoma. In most patients, Helicobacter pylori causes chronic active gastritis, mainly confined to the vestibule, without any specific disease or symptoms, but in some patients, peptic ulcer or gastric mucosal atrophy or intestinal epithelial metaplasia may occur.
The mechanism by which Helicobacter pylori causes an inflammatory response in the gastric mucosa can be divided into a direct mechanism and an indirect mechanism. The direct mechanism is that various cytotoxic factors secreted from Helicobacter pylori damage the epithelial cells, ammonia produced by Helicobacter pylori causes gastric mucosal damage, and chemotactic factors that can attract neutrophils from Helicobacter pylori enter the mucosa. It is absorbed and induces mucosal infiltration of neutrophils in the blood, etc. The indirect mechanism is that the secretion of chemotactic factors is increased in the epithelial cells, and the inflammatory cells are infiltrated.

The role of Helicobacter pylori in gastric cancer

The role of Helicobacter pylori in the development of gastric cancer is diverse. Vitamin C, an antioxidant in gastric juice, decreases, oxidative DNA damage by oxygen radicals increases, and epithelial cell proliferation and apoptosis increase. This action transforms chronic gastritis into atrophic gastritis and intestinal metaplasia, and when several environmental and genetic factors are added to this, intestinal-type gastric cancer can occur. However, given that more than half of the world's population is infected with Helicobacter pylori, and a very small number of them develop gastric cancer, the exact role Helicobacter pylori plays in the occurrence of gastric cancer is unknown.

Helicobacter pylori diagnosis method

There are many diagnostic methods to check for an infection. Among these, clinically convenient diagnostic methods include the rapid urease test (CLO test) and the urea expiratory test (UBT).
- In the rapid urease assay, gastric tissue is obtained through an endoscope and put into a medium. If there is Helicobacter pylori, the color of the medium changes from yellow to red.
- The urea breath test is a test method that can detect infection without endoscopy. If you breathe in a tube after taking a potion containing a marker, you can quickly detect Helicobacter pylori infection. However, the disadvantage is that it is expensive.

Indications for treatment of Helicobacter pylori

Not all patients infected with Helicobacter pylori are treated. Appropriate treatment targets include all peptic ulcers, including scars infected with Helicobacter pylori, low-grade MALT lymphoma, and patients after endoscopic resection of early gastric cancer.

Endoscopic treatment of early gastric cancer

Gastric cancer still ranks first in the ranking of cancer incidence in Korea. In recent years, the ratio of early gastric cancer to advanced gastric cancer is increasing due to the development of endoscopic procedures and the improvement of public awareness. For example, about 60% of all gastric cancer patients in Japan and 40% in Korea are diagnosed with gastric cancer at an early stage. The increase in early gastric cancer diagnosis has expanded doctors' attention to the issue of not only curing the disease but also improving the quality of life remaining after surgery. is playing a role. In addition, recent research results revealed that endoscopic treatment alone can achieve results comparable to laparotomy, and equipment that can improve the ease and success rate of the procedure has been developed. are receiving. In our hospital, endoscopic ultrasound is used to more accurately diagnose early gastric cancer and to perform endoscopic treatment using various methods.