General and more comprehensive text about cancer diseases, their behavior, causes and treatment can be found here.
Stomach cancer is a relatively common type of malignant disease, which has, however, one important difference from the majority of other tumors – its incidence worldwide gradually decreases. The highest incidence of this cancer is in Japan, but the reason is not entirely clear.
There are many possible causes. Probably the most probable is chronic inflammation of the gastric mucosa, which can be caused for example by Helicobacter pylori infection or by autoimmune process (such autoimmune gastritis is tightly related to vitamin B12 deficiency). Helicobacter pylori is extremely widespread in population, but that does not mean that every person with Helicobacter shall develop the stomach cancer. Other risk factor may be consumed food that irritates the gastric mucosa such as smoked and salted meals, bacon, alcohol and the lack of fruit and vegetables. Stomach cancer occurs more frequently in smokers and there are probably also some genetic factors.
The stomach cancer is insidious and its early stages cause practically no symptoms. Later, it manifests with nausea, vomiting, abdominal pain, loss of appetite and general symptoms of advanced cancer processes such as weight loss, fatigue, night sweats, etc. The tumor tissue may bleed and traces of blood could be found in laboratory examination of stool. Large tumors may even obstruct the digestive tract with regurgitation and vomiting of eaten food. Stomach cancers may cause occurrence of abdominal fluid (ascites).
Schema - tumor tissue significantly narrowing the stomach cavity
The tumor is usually diagnosed by the upper GI endoscopy (gastroscopy). This endoscopic examination not only allows to visualize the tumor mass by the camera attached to the endoscopic device, but it also enables the doctor to take small bioptic samples of tissue for histological examination. The local extent of the tumor may be examined by endosonography (especially the depth of the affection of the stomach wall). Tumor size and distant metastases can be evaluated by ultrasound or computed tomography.
The full prevention is not possible, but it is possible to decrease the risk of tumor. It is advisable to reduce the intake of salt and smoked food and increase the intake of dietary fiber, fruits and vegetables. Smoking is generally not advisable.
Small cancers can be theoretically treated by endoscopic procedures, but the tumors are usually found in more advanced forms when the endoscopic therapy is no longer possible. The most effective treatment is surgical intervention, which involves partial or complete surgical removal of the stomach. Chemotherapy can be used in combination with surgery or alone as a palliative treatment. However, the chemotherapy itself is unable to cure the tumor and it may only lengthen the patient’s life.