The stomach (abdomen) is a muscular bag, part of the digestive system (gastrointestinal tract).
- The upper part of the stomach is joined to the gullet (oesophagus) and the lower part of the stomach is joined to the beginning of the small bowel (duodenum).
- Once food has been swallowed it passes down the gullet and into the stomach where it is mixed with gastric juices.
- The semi-solid food then passes into the small bowel where it is broken down further and nutrients are absorbed.
The wall of the stomach has four layers:
- Mucosa – this is the name for the lining of the stomach.
- Submucosa – a layer underneath the mucosa.
- Muscularis – a layer of muscle beneath the submucosa.
- Serosa – this is a strong membrane that forms the outer layer of the stomach.
The most common type of adenocarcinoma (a type of cancer) of the stomach, starts in the glandular cells of the stomach lining. Other rarer types of stomach cancer include:
- Soft tissue sarcomas, the commonest are leiomyosarcomas and gastrointestinal stromal tumours (GISTs).
- Lymphomas. For example, mucosa associated lymphoid tissue (MALT) lymphomas.
- Carcinoid tumour. Relating to cancers that start in the glands around the stomach.
What Causes Stomach Cancer?
The exact causes are not known. It is thought that most adenocarcinoma stomach cancers develop as a result of a number of specific risk factors:
- Gender: Stomach cancer is more common in men.
- Age: 9 out of 10 people who develop this cancer are over 55 years old.
- Helicobacter pylori (H pylori) infection: Having H pylori infection in the stomach for an extended period of time can increase the risk of developing stomach cancer.
- Diet: Eating lots of high salt foods, pickled items and processed meats such as sausages and bacon.
- Smoking tobacco.
- Medical conditions: For example, long-term acid-reflux and Barrett’s oesophagus (abnormal cells develop on the inner lining of the lower part of the gullet) can increase the risk.
- Family history: Having a parent or a sibling (brother or sister) who has had stomach cancer can increase your risk.
What are the Symptoms?
The symptoms of stomach cancer may include any of the following:
- Indigestion or heartburn that doesn’t go away
- Excessive burping
- Loss of appetite and weight
- Difficulty swallowing
- Feeling bloated after eating
- Feeling nauseous or vomiting
- Blood in stools (bowel motion) or black stools
- Tiredness due to anaemia
Remember: If you have any of these symptoms you should have them checked by your doctor - but remember, they are common to many illnesses.
How is it Diagnosed?
After visiting a GP the patient will probably be referred to a hospital for some tests.
These may include:
- Endoscopy/ Endoscopic ultrasound. The endoscope is a thin, flexible tube with a light and camera at the end. It is used to take photographs of the lining of the stomach and to take a small sample of cells (biopsy).
- Blood test
- Barium Meal. This involves drinking a white, chalky liquid (barium) which helps the gullet and stomach to show up on an x-ray. Before a barium meal the stomach needs to be empty. The patient lies on a couch that is titled at different angles to give the best x-ray.
If the results of the test show stomach cancer, the patient will be referred to a doctor for further treatment.
The stage of a cancer describes its size and whether it has spread. The most commonly used staging system for stomach cancer is called the TNM system:
- T: refers to the size of the tumour.
- N: refers to whether lymph nodes have cancer in them.
- M: the cancer has spread to other parts of the body (secondary or metastatic cancer).
Grading refers to the appearance of the cancer cells when they are looked at under the microscope.
There are three grades:
- Low-grade: Cancer cells look very like the normal cells.
- Moderate-grade: Cancer cells look more abnormal.
- High-grade: Cancer cells look very abnormal.
How is it Treated?
A team of doctors and other staff at the hospital will plan treatment. It will depend on the size of the tumour and where it is.
The patient may be treated by an oncologist (a doctor who specialises in treating cancer with chemotherapy), a surgeon and a radiologist (a doctor who specialises in treating cancer with radiation).
Treatment may involve:
Most people have chemotherapy to shrink to size of the tumour and to get rid of any cancer cells around the body. This is usually followed with surgery to remove the tumour. More chemotherapy and radiotherapy usually follows.
Chemotherapy for stomach cancer
Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells. The drugs work by disrupting the growth of cancer cells.
- Chemotherapy drugs commonly used to treat stomach cancer include cisplatin, epirubicin, and fluorouracil (also called 5FU).
- If the patient is having surgery to remove a stomach cancer, chemotherapy may be given before the operation to help reduce the chance of the cancer coming back.
- If the cancer has spread to other parts of the body, chemotherapy may be used as the main treatment. It is given to try to shrink the cancer and reduce symptoms.
For more informationy, go to our chemotherapy fact sheet.
Surgery for stomach cancer
The aim of surgery is to remove the tumour.
- Surgery to remove part or all of the stomach: If the cancer is found at an early stage, an operation may be all that’s needed to cure it. This may involve removing part of the stomach (a partial gastrectomy) or all of the stomach (a total gastrectomy).
- Keyhole surgery: The laparoscope (little tube containing a camera) is put into the abdomen through the small cuts in the skin. Generally, about three small cuts and one larger cut are needed for the operation. The larger one is used to remove the stomach. With this type of surgery recovery time may be quicker.
For more information, go to our surgery fact sheet.
Radiotherapy for stomach cancer
- Radiotherapy treats cancer by using high-energy rays to destroy the cancer cells, while doing as little harm as possible to normal cells.
For more information, go to our radiotherapy fact sheet.