Stomach cancer (gastric carcinoma)

Stomach cancer (gastric carcinoma) is a disease in which certain cells of the stomach undergo uncontrolled division, resulting in the formation of a malignant tumor. In most cases, the gastric juice-producing glandular cells degenerate. In this case one speaks of an adeno-carcinoma. Occasionally, the lymphatic cells (MALT lymphoma) may also be affected by degeneration, or cells of muscle or connective tissue (sarcoma).

Stomach cancer is one of the most frequent tumour-related causes of death, despite its decline in recent years. The reason for this is often late diagnosis, as stomach cancer is usually only discovered at an advanced stage. As with any tumor disease, the earlier the tumor is discovered and treated, the better the therapy and cure.

Stomach cancer is the fifth most common tumour in men and the eighth most common tumour in women. With increasing age, there is also an increased incidence of stomach cancer. On average, men develop the disease around the age of 71 and women around the age of 75.

In general, there is also a difference in the incidence of stomach cancer worldwide. In Japan, for example, the incidence rate is higher than in the USA or Germany.

Several factors are suspected to increase the risk of stomach cancer and can therefore be considered as a cause:

• Dietary habits: frequent consumption of highly salted foods and low consumption of fresh vegetables and fruits are considered as a confirmed risk factor. Frequent consumption of grilled, smoked and cured foods could also be unfavorable. During the grilling or smoking process, cancer-causing substances (carcinogens) are produced in the course of incomplete combustion.
• Smoking and alcohol can also have a negative effect on the risk of stomach cancer.
• A certain form of gastritis (chronic atrophic gastritis) can be a trigger for stomach cancer. This disease is counted among the autoimmune diseases of the stomach, which causes a long-term change in the stomach lining.
• A certain bacterium, namely Helicobacter pylori, can also increase the risk. - Some gastric polyps can be the precursor of gastric cancer.
• If a partial removal of the stomach (which is less common today) has been performed, for example due to an ulcer disease, there may be an increased risk of stomach cancer.
• The rare disease with an as yet unexplained cause, Ménétrier's disease, also leads to an increased risk of stomach cancer. In this disease, there are enlarged mucosal folds, as well as larger mucus-forming layers in the stomach.

Analogous to other cancers, stomach cancer does not show characteristic symptoms in the early stages. The carcinoma grows unnoticed for a long time and without signs that would indicate a tumor.

However, if one traces the medical history of many stomach cancer sufferers, one can often notice uncharacteristic discomfort in the area of the upper abdomen. Often, a slight pressure in the upper abdomen and aversion to certain foods, such as meat, is also noticeable. Stomach cancer does not cause pain in the early stages. Weight loss and swallowing difficulties also occur later in the course of the disease. In some cases, there is slight bleeding from the stomach carcinoma, which can be recognised by bloody vomiting or black-coloured stools (tarry stools).

If the stomach carcinoma progresses further, there is often a marked loss of weight (tumour cachexia), as well as reduced general performance. Stomach ulcers that do not improve despite twelve weeks of drug treatment should be clarified, as they may indicate stomach cancer.

If there are clear signs of stomach cancer, such as vomiting blood or black stools (tarry stools), a gastroscopy is performed. In the course of this examination, the doctor takes tissue samples which are examined in the laboratory for degenerated cells.

An ultrasound examination from the inside through a stomach tube (endosonography) can be used to determine how far the cancer cells have already grown into the stomach wall. A laparoscopy, which is a surgical procedure, can reveal the extent to which a stomach cancer has already spread across the stomach.

The most common metastases in stomach cancer are found in the liver, lungs and bones. To detect possible metastases, the chest area is examined by X-ray and the abdominal area by ultrasound (sonography) and computer tomography or magnetic resonance imaging (CT). If the bones are already affected by the cancer cells, this can be detected by means of a skeletal scintigraphy.

Gastric carcinomas usually produce tumour markers that can be detected in the blood count. Particular attention should be paid to CEA (carcinoembryonic antigen), CA 72-4 and CA 19-9 (CA= cancer antigen).

If the stomach cancer can be diagnosed at an early stage, it can be removed by so-called keyhole surgery in the course of a gastroscopy. However, this method can only be used if only the gastric mucosa is affected by stomach cancer, i.e. the tumour is still in its early stages.

If the gastric carcinoma has already grown beyond the gastric mucosa, the only therapy that promises a chance of cure is partial or complete surgical removal of the stomach. Depending on the location and extent of the stomach cancer, the lymph nodes surrounding the stomach or the spleen may also have to be removed. A replacement stomach can then be reconstructed from a piece of small or large intestine. This is then connected to the remaining part of the stomach or the oesophagus so that the backflow of bile and pancreatic secretions into the oesophagus is prevented.

Life without a stomach is possible without any problems. In this case, care should be taken to ensure that food intake is achieved by eating many small meals. Initially, there may be continuous weight loss, but this usually stops on its own after some time. Digestive enzymes, as well as vitamin supplementation, mainly with vitamin B12, are given in the form of medication.

Chemotherapy and radiation therapy are most often needed for advanced stage stomach cancer, as well as right after surgery in some cases. In some cases, chemotherapy may be given before surgery. This aims to shrink the size of the tumour. If the tumor has shrunk, it may still be possible to remove it, even if chemotherapy was not able to do so.

If there is no hope of curing the cancer, an artificial feeding tube (PEG, percutaneous endoscopic gastronomy) must be inserted in many cases. Painkillers (analgesics) are effective against pain.

Stomach cancer that is detected at an early stage usually has a good chance of being cured. However, stomach cancer is often diagnosed late. The prognosis also depends on metastasis to surrounding organs and lymph node involvement. In this case, the prospects of recovery are more complicated. Generally, five years after diagnosis, 31 percent of female patients and 35 percent of male patients are still alive.