With approximately 15,000 new sufferers per year, stomach cancer ranks seventh among cancers in men and ninth among women in Germany. It mainly affects people over 70 and more men than women. It is true that the incidence and mortality rate have been declining overall in recent decades. But the prognosis could still be improved if the cancer were detected earlier.
Causes of stomach cancer: how does stomach cancer develop?
Malignant tumors of the stomach (gastric carcinoma) usually arise in the lining of the stomach. Ninety-five percent of them originate from the glandular tissue. Despite declining numbers of cases, gastric cancer remains one of the most common tumor-related causes of death. This is mainly because stomach cancer is very often diagnosed too late and the chances of cure are correspondingly low.
A number of factors are now known that have been shown to increase the risk of stomach cancer or are suspected to be associated with it. These include:
- Dietary habits
- Helicobacter pylori
- Stomach diseases
- Genetic factors
Dietary habits as a cause
A particularly important role is played by certain dietary habits that are harmful: Frequent consumption of spicy and heavily salted foods, as well as heavily fried, smoked or cured foods. The nitrates contained are converted in the stomach by bacteria into nitrites, from which carcinogenic nitrosamines are formed.
Excessive consumption of nicotine (tobacco smoke contains nitrite) and alcohol also promote gastric inflammation and ulcers and thus malignant degeneration. This is especially true if too little vitamin C is consumed at the same time
Cause: infections
Another risk factor is inflammation of the stomach lining caused by the bacterium Helicobacter pylori. This is especially true if the diet is high in meat: meat contains iron, which is vital for the germ.
An American study shows that when Helicobacter pylori colonizes the stomach, the amount of a certain inflammatory protein (interleukin-1-beta) increases, which in turn increases the risk that normal stomach cells will turn into cancer cells. How much interleukin is produced is probably genetically determined – which would explain why the germs don’t lead to cancer in everyone.
Diseases of the stomach as a cause
In addition, there are some rare, specific stomach diseases that also increase the risk. These include, for example, certain gastric polyps, Ménétrier syndrome (giant wrinkled stomach), or autoimmune gastritis – a form of stomach inflammation in which too little stomach acid is produced, which in turn promotes germ colonization.
Genetic factors as triggers of gastric cancer
Genetic factors probably also play a role in the development of stomach cancer – stomach cancer occurs more frequently in certain regions and in close relatives. Scientists estimate that the personal risk of stomach cancer is approximately 3.7 times higher if a first-degree family member (parents, children, siblings) already has stomach cancer.
