Stomach cancer

Stomach cancer is a tumor that originates from the gastric mucosa. The biggest risk factor is an infection of the stomach with the bacteria known as helicobacter pylori. If the condition has progressed locally, many patients require extensive surgery.

At a glance

  • Stomach cancer is a tumor condition of the gastric mucosa.
  • In most patients, the tumor originates from the pancreatic ducts of the mucosa.
  • Indications of stomach cancer are non-specific in many patients; for example, nausea and loss of appetite can have other causes.
  • If stomach cancer is suspected, a gastroscopy is performed in which a tissue sample may be taken.
  • The type of treatment for stomach cancer depends on the tumor’s stage.
  • In addition to tumor treatment, those affected require individual nutritional counseling.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Stomach cancer: man holding his abdomen with both hands. He appears to be in severe pain.

What is stomach cancer?

Stomach cancer is a malignant tumor condition of the gastric mucosa. The tumor originates from the pancreatic ducts of the gastric mucosa in most patients. Doctors call this adenocarcinoma of the stomach. 

If the tumor is located at the opening from the esophagus to the stomach, it is called adenocarcinoma of the esophagogastric junction (GEJ adenocarcinoma). Depending on the exact location, it is treated as either esophageal cancer or stomach cancer. 

What causes stomach cancer? More information is available on the German Cancer Research Center’s Cancer Information Service) website (in German).

What are the symptoms of stomach cancer?

For many patients, stomach cancer in its early stages does not exhibit symptoms. If the patient experiences initial symptoms, they are often atypical and could be linked to a different illness. 

Doctors recommend an image of the stomach and the esophagus be taken if the following symptoms are present: 

  • difficulties swallowing 
  • recurrent vomiting 
  • persistent loss of appetite 
  • unexplained weight loss 
  • atypical, dark stool known as tarry stool due to bleeding

Those with persistent symptoms should see a doctor. General Practitioners can already narrow down what is causing the symptoms and, if necessary, initiate further diagnostic steps with specialists. 

What causes stomach cancer?

Researchers are still not completely sure why some people become ill with stomach cancer and others do not. Most likely, various factors play a role, as is the case with other cancer diseases. Some risk factors for stomach cancer are known. Infections and other underlying conditions of the stomach often play a role. Lifestyle also appears to play a role. 

The following risk factors apply to stomach cancer: 

  • chronic gastritis due to an infection of the stomach with the bacteria helicobacter pylori 
  • an infection with Epstein-Barr virus 
  • smoking 
  • excessive alcohol consumption 
  • consumption of foods preserved with salt, a diet high in salt, and consumption of meat 
  • stomach operation 
  • close relatives such as parents, siblings, or children with stomach cancer 
  • some hereditary syndromes, such as Ménétrier disease or Lynch syndrome 

Not everyone who lives with one or more risk factors becomes ill with stomach cancer. Then again, people without these risk factors have no guarantee that they will remain healthy. 

Looking for more information about the risk factors of stomach cancer? The correlation between risk factors and the causes of stomach cancer are detailed on the German Cancer Research Center’s Cancer Information Service website (in German). 

How many people become sick with stomach cancer each year?

In Deutschland erkranken jährlich rund 15.000 Menschen an Magenkrebs. Männer sind häufiger betroffen als Frauen.

Around 15,000 people get stomach cancer every year in Germany. Men are more often affected than women. The risk of disease increases with age. On average, men become ill at the age of 72 and women at the age of 76 years. 

Stomach cancer: how does the disease progress?

The progression of stomach cancer depends on the size of the tumor, its stage, and how aggressive it is, among other things. Initially, the tumor is limited to the top layer of the mucosa. If it continues to grow, it penetrates the deeper layers of the stomach wall. Over time, the tumor can spread to nearby tissue, to lymph nodes, and to other organs. 

Tumor cells in other organs (metastases)

Cancer cells can reach other organs and build metastases there via the blood stream or lymphatic system. Metastases appear most often in the lymph nodes, the liver, and the lungs with stomach cancer. But other organs can be affected. 

How can stomach cancer be prevented?

Some diseases of the stomach increase the risk of becoming sick with stomach cancer later on. They include long-term infections of the gastric mucosa, such as chronic gastritis or a gastric ulcer.

The stomach bacteria, helicobacter pylori, is the cause of these illnesses in most patients. The bacteria reside in the gastric mucosa and damage it. Carriers of the bacteria can be treated with antibiotics. This lowers the risk of stomach cancer. 

People of the following groups can be tested for helicobacter pylori: 

  • patients with chronic inflammation of or changes to the gastric mucosa
  • people with close relatives (parents, children, or siblings) who have stomach cancer

In Germany, approx. 3 out of 10 adults are infected with helicobacter pylori. Of course, not every person infected with the bacteria has stomach cancer. This is why specialists do not recommend testing everyone for the bacteria.

How do doctors diagnose stomach cancer?

A gastroscopy is used by doctors to reliably diagnose stomach cancer. During the examination, a flexible tube about as thick as a finger (endoscope) is inserted through the mouth, into the esophagus and then the stomach. 

A small camera is located on the tip of the endoscope, which transmits images from inside the body onto a monitor. The doctor can evaluate changes in the gastric mucosa and remove tissue samples from areas that look suspicious. 

The examination is only slightly inconvenient for patients. However, many people find a gastroscopy unpleasant. A sedative can be prescribed before the examination upon request. 

Complications from a gastroscopy are rare. 

The tissue samples are sent to a special lab and viewed under a microscope. Typically, it takes a few days before the results are available. 

Cancer diagnosis – what’s next? 

If the diagnosis is stomach cancer, additional tests are needed. Doctors determine if the tumor has already spread and if metastases have already formed. Specialists call this “staging”. 

  • First, the doctor performs an ultrasound on the abdomen to look for metastases in the liver. 
  • A computed tomography (CT) scan of the chest, abdomen, and pelvis makes it possible to locate metastases in other organs. Furthermore, it allows doctors to find out how deep the tumor has grown into the stomach wall. Another option is magnetic resonance imaging (MRI). 
  • Additional tests, as needed, are an endoscopic ultrasound of the stomach, ultrasound of the throat, positron emission tomography, laparoscopy, or bone scintigraphy. 

The attending physicians then create a treatment plan based on the staging results. 

For more information about the progress and possible risks of the various examination methods, visit the website of the Cancer Information Service of the German Cancer Research Center (in German). 

What are the treatment options for stomach cancer?

Doctors consider the following in particular when selecting the appropriate form of treatment:

  • Tumor location and characteristics on the cellular level
  • The tumor stage: how far has the tumor grown into the stomach’s tissue and how far have the cancer cells spread in the body?
  • The general condition of the patient: what is the patient’s nutritional condition and are there underlying conditions?
  • Wishes and needs of the patient
Possible methods for treating stomach cancer include endoscopic therapy, surgery, pre- and post-operative chemotherapy and chemoradiotherapy.

How is cancer treated?

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Localized tumor (early-stage carcinoma)

Endoscopic treatment: very small tumors on the surface can often be removed endoscopically. The procedure is similar to a gastroscopy in which a tube is inserted through the esophagus into the stomach. If, during the procedure, the doctor determines that the tumor cannot be completely removed, an operation may be necessary.

Locally advanced tumor


If the tumor is in an advanced stage, but still confined to the stomach, an operation is performed to remove as much of the tumor as possible. Depending on the tumor’s size, stage, and location, part of the stomach or the entire stomach is removed. The operation is the only way to cure stomach cancer that has penetrated through the mucous membrane and into the deeper tissue layers.

Pre- and post-operative chemotherapy

Depending on the stage of the tumor, some patients require chemotherapy in addition to surgery. It is typically started before the operation and continued after. The goal is to shrink the tumor before the operation to lower the likelihood of a relapse after the operation.


Radiation is recommended for only a few patients, since stomach cancer does not respond well to radiation. Chemoradiotherapy is considered if an operation is not possible, and stopping the disease from advancing and curing the cancer to the greatest extent possible is the goal.


In some patients, the tumor has spread to the rest of the body and cannot be cured. In these advanced stages, the tumor has spread to other organs and tissues.

The attending physicians then try to slow the spread of the tumor clusters with chemotherapy and stop their growth for as long as possible. Depending on the characteristics of the tumor’s tissue, medication can be prescribed in addition to chemotherapy. This medication is used to stop the growth of cancer cells. Treating distressing symptoms is also important in this situation.

For details about stomach cancer treatments and the associated side effects, visit the German Cancer Research Center’s Cancer Information Service website (in German).

Do stomach cancer patients need rehab?

Stomach cancer is physically and psychologically difficult. Patients need time to recover after treatment. Patients whose stomachs are partially or completely removed must become accustomed to a new way of eating. 

Rehabilitation can help them make the transition to daily life. It also helps to prevent long-term side effects of the illness or its treatment. 

Patients can consult with their doctors to discuss rehabilitation options. They certify what kind of rehabilitation is needed. Questions about rehabilitation can be answered by medical social work services at the hospital and at the local cancer consultation office, and by health insurance providers. 

Looking for more information about rehabilitation after oncological disorders and contact information for socio-legal advice? The website of the German Cancer Research Center’s Cancer Information Service provides further details (in German). 

What kind of aftercare is available for stomach cancer?

Most patients with stomach cancer must regularly schedule aftercare appointments at their doctor’s office or the hospital after treatment. The objectives of these aftercare appointments are to monitor the general condition of the patient and offer supportive measures for side effects of the illness or its treatment. Furthermore, they are designed to detect signs of a relapse early on. 

Another aspect of aftercare is monitoring the nutritional condition of the patient. For example, patients experiencing difficulties in getting proper nutrition can receive nutrition consultation. Psychological counseling is also available as part of aftercare. 

During aftercare, the doctor examines the patient regularly, initially at shorter intervals and then longer ones. If the tumor was removed endoscopically, multiple gastroscopies are part of aftercare. After an operation or chemoradiotherapy, the doctor looks for new symptoms that may have appeared. 

If the stomach cancer is advanced and cannot be cured, specialists recommend regular progress monitoring. Doctors check the patient’s general condition and blood values. In addition, they employ imaging techniques. Medical practitioners use these to check how the illness is developing. Adverse symptoms can be recognized early on and treated to provide the best quality of life possible. 

What is the role of good nutrition with stomach cancer?

Many patients with stomach cancer have already lost a lot of weight by the time they are diagnosed. Additionally, treatment makes it difficult to get enough calories and important nutrients. Patients who undergo extensive stomach surgery find it difficult to adjust their nutrition to their new situation. 

Nutrition before treatment

Prior to treatment, the doctor assesses the nutritional condition of the patient. Since surgery has a negative impact on nutrition, stomach cancer patients often receive liquid nutrition (“astronaut food”) a few days prior to the operation. 

Nutrition after treatment

Immediately after operation, many patients are completely artificially fed. After some time, most patients are fed through a tube in the part of the stomach that remains or the upper part of the intestine. Fairly shortly thereafter, the patient can cautiously start to eat normally again. Some weight loss is normal during this time. However, few patients ever return to their original weight. 

Patients whose stomachs have been completely removed are unable to absorb vitamin B12 through their food. Even if only part of the stomach has been removed, it is possible that their nutritional intake is insufficient. That is why patients are often given the vitamin in the form of a shot at regular intervals.

Who are the points of contact for stomach cancer?

Doctors from a variety of disciplines work together closely to treat stomach cancer. Hospitals with a great deal of experience in treating patients with stomach cancer can demonstrate this through certification. The German Cancer Society regularly checks the hospitals for compliance with certain professional requirements. 

You can find the addresses of the certified centers on the OncoMAP website.  

Do you have further questions about dealing with the condition in everyday life and additional support options? You can find information about this on the website of the Cancer Information Service of the German Cancer Research Center (in German).

For questions about stomach cancer, contact the Cancer Information Service by dialing 0800 - 420 30 40 (toll free) or send an email to 

In cooperation with the Cancer Information Service of the German Cancer Research Center (Krebsinformationsdienst des Deutschen Krebsforschungszentrums).

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