The stomach is a storage organ for food. When you eat your meals, food stays in the stomach for a while, and this is where digestion starts. Food is churned up, and mixed with acid until it is partly liquefied, when it is passed on into the rest of the bowel for further digestion, and for the nutrients to be absorbed. The stomach is actually a large hollow muscle, whose movement is controlled by nerves and hormones, triggered by the sight, smell or sound of food.
How does stomach cancer start?
Cancers of the stomach are not all the same, and it is likely that there are different causes. Certain conditions of the stomach may predispose to stomach cancer. These include pernicious anaemia, chronic inflammation, ulcers and large polyps.
Smoking, and a high salt or high nitrate/nitrite diet may also cause problems. Nitrites are found in cured meats, pickled fish, and may also originate in fertilisers.
Helicobacter pylori is a bacterium which can infect the stomach. This may lead to ulcers, and is also thought to predispose to stomach cancer.
Stomach cancer does not often run in families; a family history of stomach cancer is found in less than one in ten patients with the condition.
Does early diagnosis make a difference?
The earlier a diagnosis can be made, the more likely it is that the problem can be cured. The longer a cancer is present in the stomach, the more likely it is that it will spread to other parts of the body such as lymph glands and the liver.
What are the symptoms of stomach cancer?
The symptoms of stomach cancer may include any of the following:
- Indigestion that does not go away
- Losing your appetite
- Difficulty in swallowing
- Losing weight
- A bloated feeling after eating
- Feeling sick (nausea) or being sick (vomiting)
- Blood in the stools (bowel motion) or black stools
- Tiredness due to anaemia (from bleeding from the wall of the stomach)
Many of the symptoms described above are common to conditions other than cancer of the stomach. Most people who see their doctor with these symptoms will not have cancer. However, it is important to have them checked so that further tests can be done if necessary.
How is the diagnosis made?
Occasionally a lump can be felt in the abdomen, but other tests are always needed.
- Endoscopy (video examination of the stomach). This is a simple test carried out under local anaesthetic. A small sample of tissue is taken for examination under a microscope (histology) and a test is taken for Helicobacter pylori, a bacterium which can infect the stomach and is thought to increase the risk of stomach cancer.
- CT scan – this is an X-Ray which takes 3 dimensional pictures of the chest, abdomen and pelvis areas. It gives information about the stomach itself, and also about other areas that disease may have spread to.
How are cancers of the stomach treated?
Once checks have been made that it has not spread anywhere else, most stomach cancers will be removed by surgery. Either a part of the stomach or the whole stomach is removed, with lymph glands that are close by. The stomach or gullet is then joined to the bowel (anastomosis). Once the cancer has been removed it is examined closely under the microscope to decide exactly what stage it is at. If the cancer is an early one that has not spread through the stomach wall, then no further treatment may be necessary. If the cancer has spread through the wall,or involved lymph glands you may be offered further treatment such as chemotherapy, radiotherapy or a combination of both. Sometimes chemotherapy is given before surgery.