Stomach Cancer

The stomach is a J-shaped organ in the upper abdomen where the food is broken down (digested).

The chance of getting stomach cancer is higher if the patient has had an infection of the stomach caused by Helicobacter pylori.

Once cancer of the stomach is found, more tests will be done to find out if cancer cells have spread to other parts of the body.

Gastric cancer is curable if diagnosed in the early stages.

Because the symptoms appear relatively late in the course of the disease, many patients present in an advanced stage.

What is cancer of the Stomach?

Cancer of the stomach, also called gastric cancer, is a disease in which cancer (malignant) cells are found in the tissues of the stomach. The stomach is a J-shaped organ in the upper abdomen where the food is broken down (digested).

Food reaches the stomach through a tube called the oesophagus that connects the mouth to the stomach. After leaving the stomach, partially digested food passes into the small intestine and then into the large intestine (the colon). Sometimes cancer can be in the stomach for a long time and can grow very large before it causes symptoms.

In the early stages of cancer of the stomach, a patient may have:

indigestion and stomach discomfort

a bloated feeling after eating

mild nausea

loss of appetite

heartburn

In the more advanced stages of stomach cancer the patient may have:

blood in the stool

vomiting

weight loss

pain in the stomach

Risk Factors

The chance of getting stomach cancer is higher if the patient has had an infection of the stomach caused by Helicobacter pylori.

Other factors that increase the chances of getting stomach cancer are a stomach disorder called atrophic gastritis, a disorder of the blood called pernicious anaemia, or a hereditary condition of growths (called polyps) in the large intestine.

The chances of stomach cancer are also higher if the patient is older, is a man, smokes cigarettes, or frequently eats a diet that includes lots of dry, salted foods.

If there are symptoms, a doctor will usually order an upper gastrointestinal X-ray (also called an upper GI series). For this examination, the patient drinks a liquid containing barium, which makes the stomach easier to see in the X-ray. This test is usually performed in a hospital radiology department.

The doctor may also look inside the stomach with a thin, lighted tube called a gastroscope. This is called a gastroscopy, and it finds most cancers of the stomach. For this test, the gastroscope is inserted through the mouth and guided into the stomach. The doctor may spray a local anaesthetic (a drug that causes loss of feeling for a short period of time) into the throat, or give the patient other medicine before the test so that no pain is felt.

If the doctor sees tissue that is not normal, he or she may cut out a small piece so it can be looked at under a microscope to see if there are any cancer cells. This is called a biopsy. Biopsies are usually done during the gastroscopy.

The chance of recovery (prognosis) and choice of treatment depend on the stage of the cancer (whether it is just in the stomach or if it has spread to other places) and the patient's general state of health.

Diagnosis

Stages of cancer of the stomach

Once cancer of the stomach is found, more tests will be done to find out if cancer cells have spread to other parts of the body. This is called staging. The doctor needs to know the stage of the disease to plan treatment. The following stages are used for cancer of the stomach:

Stage 0

This is very early cancer. Cancer is found only in the innermost layer of the stomach wall.

Stage I

Cancer is in the second or third layers of the stomach wall and has not spread to lymph nodes near the cancer, or is in the second layer of the stomach wall and has spread to lymph nodes very close to the tumour. (Lymph nodes are small bean-shaped structures that are found throughout the body. They produce and store infection-fighting cells.)

Stage II

Any of the following may be true:

Cancer is in the second layer of the stomach wall and has spread to lymph nodes further away from the tumour.
Cancer is only in the muscle layer (the third layer) of the stomach and has spread to lymph nodes very close to the tumour.
Cancer is in all four layers of the stomach wall but has not spread to lymph nodes or other organs.

Stage III

Any of the following may be true:

Cancer is in the third layer of the stomach wall and has spread to lymph nodes further away from the tumour.
Cancer is in all four layers of the stomach wall and has spread to lymph nodes either very close to the tumour or further away from the tumour.
Cancer is in all four layers of the stomach wall and has spread to nearby tissues. The cancer may or may not have spread to lymph nodes very close to the tumour.

Stage IV

Cancer has spread to nearby tissues and to lymph nodes further away from the tumour or has spread to other parts of the body.

Recurrent:

Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the stomach or in another part of the body such as the liver or lymph nodes.

Treatment

There are treatments for most patients with cancer of the stomach. Three kinds of treatment are used:

Surgery (taking out the cancer in an operation)

Chemotherapy (using drugs to kill cancer cells)

Radiation therapy and biological therapy are being tested in clinical trials.

Surgery

Surgery is a common treatment for all stages of cancer of the stomach. The doctor may remove the cancer using one of the following operations:

Subtotal gastrectomy removes the part of the stomach that contains cancer and parts of other tissues and organs near the tumour. Nearby lymph nodes are also removed (lymph node dissection). The spleen (an organ in the upper abdomen that filters the blood and removes old blood cells) may be removed if necessary.

Total gastrectomy removes the entire stomach and parts of the oesophagus, the small intestine, and other tissue near the tumour. The spleen is removed in some cases. Nearby lymph nodes are also removed (lymph node dissection). The oesophagus is connected to the small intestine so a patient can continue to eat and swallow.

If only part of the stomach is removed, a patient should still be able to eat fairly normally. Frequent small meals may need to be eaten, as well as foods low in sugar and high in fat and protein, if the entire stomach is removed. Most patients can adjust to this new way of eating.

Chemotherapy

This uses drugs to kill cancer cells. Chemotherapy may be taken by pill, or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the stomach.

Treatment given after surgery when no cancer cells can be seen is called adjuvant therapy. Adjuvant therapy for cancer of the stomach is being tested in clinical trials.

Radiation Therapy

Radiation Therapy uses high-energy X-rays to kill cancer cells and shrink tumours. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation (radioisotopes) through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy).

Biological therapy tries to get the body to fight cancer. It uses materials made by the body or made in a laboratory to boost, direct, or restore the body's natural defences against disease. Biological therapy is sometimes called biological response modifier (BRM) therapy or immunotherapy.

Treatment by stage

Treatment of stomach cancer depends on the stage of the disease, the part of the stomach where the cancer is, and the patient's general health.

Standard treatment may be considered because of its effectiveness in patients in past studies. However, many patients with cancer of the stomach are not cured with standard therapy and some standard treatments may have more side effects than are desired. For these reasons, clinical trials are designed to find better ways to treat cancer patients and are based on the most up-to-date information.