Stomach cancer is not uncommon, with around 15,000 new cases per year on the list of carcinomas. 9,300 men and 5,600 women are affected. The cause of the gender difference is currently unknown.

Stomach cancer is not one of the most common cancers, but the chances of survival are not good. Two thirds ultimately die of the tumor disease. “We have to assume that three out of four patients will only be diagnosed in a locally extended or even metastatic situation,” reports Michael Stahl, head of the Clinic for Internal Oncology at the Evangelical Clinics Essen-Mitte (KEM).

This late diagnosis means that three quarters of the patients have a poor prognosis and cannot be cured with an operation alone, summarizes the oncologist, who is among other things the author responsible for the German guideline for the diagnosis and treatment of esophageal cancer and a member of the lead group of the Working Group on Internal Oncology for carcinomas of the stomach and esophagus.

Cause of stomach cancer unknown, but there are risk factors

“The only good relative risk factor for stomach cancer is the stomach germ Helicobacter pylori,” explains the expert. That would be risk factor number 1.

However, around a quarter of Germans are infected with this bacterium, but only a fraction of them develop gastric cancer. Why they get sick is not yet fully understood, just as much is still unknown about the causes of stomach cancer.

There is also evidence that smoking increases the risk. And what about alcohol? “However, there is no meaningful evidence that alcohol also increases the risk of stomach cancer,” adds the oncologist. However, it can lead to gastric mucosal inflammation, i.e. gastritis, up to and including gastric ulcer.

Chronic gastric mucosal inflammation and reflux disease could in turn increase the risk of gastric cancer at the junction with the esophagus.

Stomach cancer can also develop from previous operations on the stomach.

The reflux of bile is also considered a risk factor. This danger arises from being very overweight.

And on the subject of obesity and nutrition: Scientists assume that a one-sided diet with a lot of processed meat products, heavily salted, but also smoked and grilled foods promote stomach cancer – keyword nitrosamines, which are known to be carcinogenic. Rotten and moldy foods pose a general health risk, also with regard to stomach cancer.

Stomach cancer with certain genetic changes

In addition, there are genetic components in the development of gastric cancer: first-degree relatives (children, siblings) of patients with gastric cancer have an increased risk – that is, when the father, mother or sibling are ill. In addition, stomach cancer can occur if a certain form of colon cancer is already present (hereditary colorectal cancer) or breast cancer.

These are patients with changes in their genetic makeup, for example what is known as microsatellite instability (MSI). You are at an increased risk of various types of cancer, including cancer of the stomach and intestines. “Doctors should keep this in mind if a patient has a colon cancer with microsatellite instability , or if there are several carcinomas in the family,” emphasizes the oncologist from Essen.

However, all of these are only possible risk factors. “Of most patients who fall ill, we don’t know why, because none of these risk factors apply to them,” summarizes Michael Stahl.

Look out for these warning signs

In addition to this fact, there is the second difficulty in gastric cancer – the late diagnosis. This is because the symptoms are rather unspecific, affecting the stomach, but are often dismissed as harmless everyday complaints. Early signs can be:

• Feeling full, pressure in the stomach
• general upper abdominal discomfort
• Eructation
• nausea
• Vomit
• Flatulence
• Loss of appetite

“Anyone who has one or more of these complaints for more than three weeks should have them checked out by a doctor,” advises Michael Stahl.

Do not treat persistent stomach problems with acid blockers on your own initiative

However, many sufferers do not take these symptoms seriously and try to alleviate them first with self-medication – wasting valuable time on early cancer therapy and thus a high chance of recovery.

They resort to gastric acid blockers that are available over the counter or prescribed by doctors. The pain will actually go away. “Cancer itself does not cause the pain at the beginning of the disease, rather the mucous membrane defect it causes is irritated by stomach acid – and that triggers the pain,” explains the expert.

This pain disappears when the stomach acid is blocked because it no longer irritates the mucous membrane. The cancer growth is not influenced by this, the tumor can spread undisturbed.

The most important diagnostic tool – gastroscopy

The oncologist therefore urgently recommends that the complaints be clarified by a quality-assured endoscopy, i.e. in a gastroenterological practice that carries out these examinations on a daily basis or in an appropriate center.

The gastroscopy only takes a few minutes, the doctor can not only check the condition of the esophagus and stomach up to the duodenum, but can also test whether Helicobacter is present and possibly take additional tissue samples.

Usually no tumor is discovered, but rather the germ in the stomach or an enlargement or displacement of the area between the stomach and esophagus (hernia), which can lead to reflux. A change in diet can help here or medication may be necessary. Sometimes, however, the doctor finds stomach cancer, “and more and more often in the transition area to the esophagus,” reports the expert from the practice.

The reason for this is that there are more and more people who are very overweight. “Being overweight puts pressure on the abdominal cavity, which is why bile acids and stomach acid flow back into the transition area to the esophagus, which is not designed for frequent contact with these acids and is therefore damaged,” says Michael Stahl, summarizing the chain of reactions.