Certain factors increase the risk of developing stomach cancer.

Along with a certain hereditary component, diet plays an important role. Smoking also has an impact on the development of stomach cancer. A bacterial infection and a history of stomach illnesses can increase the risk of stomach cancer.

Risk factor: Diet

Particular risk factors are the frequent consumption of food high in salt and seldomly eating fresh fruit and vegetables. Cured, grilled and smoked foods, too seem to increase the risk of developing stomach cancer.   

Risk factor: Infections

Inflammation of the stomach lining caused by Helibactor pylori bacteria can increase the risk of developing stomach cancer.

Risk factor: History of stomach diseases

A history of different stomach diseases such as chronic inflammation of the stomach lining can increase the risk of stomach cancer.

Patients suffering from benign growths in the stomach lining (gastric polyps) and from a certain type of anaemia are also at a higher risk.

People who have had surgery on their stomachs some time ago are at an increased risk, too.

Risk factor: Smoking

Smoking is seen as being another risk factor for stomach cancer. Some of the substances resulting from cigarette and tobacco smoking are carcinogenic. These dissolve in the saliva and so enter the stomach. It is estimated that smokers have something like a three times higher risk of contracting stomach cancer.  

 Risk factor: genetic disposition

In some families, stomach cancer occurs more frequently.

Particular risk factors are the frequent consumption of food high in salt and seldomly eating fresh fruit and vegetables. Cured, grilled and smoked foods, too seem to increase the risk of developing stomach cancer.

Particular risk factors are the frequent consumption of food high in salt and seldomly eating fresh fruit and vegetables. Cured, grilled and smoked foods, too seem to increase the risk of developing stomach cancer.

The following symptoms could point to stomach cancer and should be reported to a doctor:

• Pain in the upper abdomen
• Feeling of pressure and bloating
• Burping
• Bad breath
• Nausea
• Vomiting
• Flatulence
• Loss of appetite
• Sudden aversion to certain food, in particular to meat
• Weight loss
• Black stools
• Paleness and fatigue
• Loss of performance

All these symptoms can have harmless causes or they could point to stomach cancer.

If stomach cancer is diagnosed at an early stage, the prognosis is good.

Besides a physical exam, physicians may order stool and blood tests and perform an ultrasound exam on the upper abdomen. A gastroscopy allows for fast, reasonably certain and, most importantly, early diagnosis. During a gastroscopy the upper part of the digestive system is visualised. Physicians will insert a tube with a light source into the oesophagus and stomach down to the small intestine.     

Changes to the mucosa can be detected here. Physicians will also remove targeted tissue samples. These are examined under a microscope.  

If stomach cancer is confirmed by the physician, further examinations will follow. These will show how far the tumour has spread already, whether lymph nodes are affected or whether metastases have grown in other regions of the body.

Common examinations include:

• Ultrasound (sonography)
• Laboratory tests
• Endosonography (endoscopic ultrasound)
• Lung x-ray

The following can be used in addition:

• Computer tomography (CT)
• Laparoscopy
• Magnetic resonance imaging (MRI) of the liver

Only once all necessary examinations have been concluded, physicians and patients can decide together which treatment measures are best suited to the individual circumstances.

The following treatment methods are available for stomach cancer:  

• Surgery
• Chemotherapy
• Radiation therapy

The most important procedure for treating stomach cancer is surgery. The surgery’s goal is to resect the tumour completely and thereby achieve long-term remission of the cancer. Further possible options are chemotherapy and, in some situations, radiation therapy.

Surgery

During surgery, the surrounding lymph nodes are also removed as a matter of principle. This is a safety measure as the tumour cells can spread by the lymphatic system. In addition, microscopic examinations of the removed lymph nodes can determine the present spread of the disease.

Chemotherapy

Chemotherapy is aimed at destroying cancer cells in the whole body with medicinal products that inhibit cell growth (cytostatics). Cytostatics are very effective against rapidly growing cells, a property that applies in particular to cancer cells.

Stomach cancer cannot be cured by the administration of cytostatics alone.

Chemotherapy before and after surgery improves the patient’s prognosis once the tumour has reached a certain size.

Antibody therapy

If the stomach cancer has already metastasised antibody therapy can be used. The active substance is administered as an infusion every three weeks in combination with chemotherapy.   

Radiotherapy

Radiation therapy is occasionally used in stomach cancer if the patient cannot be operated on or does not respond to chemotherapy. Radiation therapy is mostly used to alleviate pain and treat metastasis.  

Currently, radiation therapy in combination with chemotherapy is also used before surgery. In addition to chemotherapy, radiation therapy can help shrink the tumour.

Pain therapy

In an advanced stage of the cancer, patients often experience pain. In those cases, effective pain relief is very important. In most cases, tumour pain can be treated quite effectively with modern medicines and methods.

With the exception of the gastroscopy and the fecal occult blood test for hidden blood in the stools the extensive examinations during stomach-cancer diagnosis serve to determine the tumour stage (staging). Treatment and prognosis depend on the stage. Important criteria for the staging are the size of the tumour, whether surrounding organs have been invaded and whether metastasis is present in the lymph nodes and distant organs. 

According to the international TNM classification the following categories apply to the tumour stage:

T: Primary tumour (cancerous growth that appeared first)

• T is Carcinoma in situ, i.e. the cancer is limited to the surface of the stomach lining. At this stage, there is no metastasis.
• T1 Early cancer: Early cancer is where the tumour in the stomach has only grown near the surface into the stomach lining (mucosa) and the tissue layer underneath the mucosa (submucosa), and has not yet reached the deeper layers. If the tumour has already invaded the deeper wall layers it is called “advanced cancer”.
• T2 The tumour has invaded the muscularis propria layer, i.e. the tumour has grown into the muscle layer of the stomach.
• T3 The tumour has invaded the subserosa layer but not surrounding organs and structures.
• T4 The tumour has invaded surrounding structures (e.g. spleen, large intestine, liver, diaphragm, pancreas, abdominal wall, kidneys, adrenal glands, small intestine).

N: Involvement of lymph nodes N = nodes (nodus, Latin for knots)

• N0 No invasion of lymph nodes.
• N1 Invasion of 1 to 2 surrounding (regional) lymph nodes
• N2 Invasion of 3 to 6 surrounding (regional) lymph nodes
• N3 Invasion of 7 to 15 surrounding (regional) lymph nodes (N3a) or more than 15 surrounding lymph nodes (N3b).

M: Distant metastasis

• M0 No distant metastasis.
• M1 Distant metastasis

Laurén classification

In addition to TNM classification, Laurén classification is used in stomach cancer, which is particularly important for the scope of surgery. It distinguishes between different growth forms:

• Intestinal type: There is polypoid growth of the cancer into the stomach and it is well differentiated. This type has good prognosis.
• Diffuse type: The cancer grows in the stomach walls and is poorly differentiated. Early metastasis means that prognosis is poor.
• Mixed type: The cancer grows towards the stomach lumen as well as laterally inside the stomach wall.

In addition, the differentiation of the tumour cells is graded into

• G1 = well-differentiated (highly similar to healthy body cells)
• G2 = moderately differentiated
• G3 = poorly differentiated
• G4 = undifferentiated (no resemblance to mature, healthy body cells)

The higher the differentiation of its cells (i.e. the lower the grade) the slower and less aggressive the tumour’s growth.

Metastasis means the malignant tumour has spread elsewhere. In stomach cancer, the following types of metastasis can occur:

• Lymph node metastasis Around 70 per cent of stomach cancer patients have lymph node metastasis when they are first diagnosed. In stomach cancer, the Virchow’s lymph nodes, one of the left supraclavicular lymph nodes, are often affected.
• Distant metastasis: Spread of the stomach cancer cells with metastasis by the blood stream invades above all the liver, followed by the lungs, bones and brain.
• Extension per continuitatem: If the stomach cancer invades the surrounding organs, i.e. the oeosophagus, small intestine, large intestine and pancreas, further metastasis can develop.
• Drop metastases: When tumour cells become detached from the outside of the stomach wall, the stomach cancer can spread to the peritoneum (peritoneal carcinomatosis). Fluids are then discharged into the abdominal cavity (ascites). So-called drop metastases can also form in the ovaries or the Douglas pouch (deepest point of the pelvis).

Malignant lymphoma, also known as MALT lymphoma, are a special phenomenon in stomach cancer. MALT lymphoma consists of malignantly mutated lymphatic tissue in contrast to the other tumours that consist of malignant gastric mucosa tissue.