Stomach Cancer

Stomach Cancer

This factsheet is for people who have stomach cancer, or who would like information about it.

About 7,700 people get stomach (gastric) cancer each year in the UK. It mostly affects people over 55 and is more common in men. Stomach cancer is usually treated with surgery, chemotherapy, and less often, radiotherapy.

• How cancer develops
• About stomach cancer
• Symptoms of stomach cancer
• Causes of stomach cancer
• Diagnosis of stomach cancer
• Treatment of stomach cancer
• Prevention of stomach cancer

The stomach is the sac-like organ located in the upper abdomen, under the ribs, which plays a role in the digestion of food. It connects the esophagus (e-SOF-a-gus), the tube that carries swallowed food, with the small intestine, which absorbs the nutrients needed by the body. When food enters the stomach, the muscles in its wall create a rippling motion that mixes and mashes it. The glands in the lining of the stomach release juices that help to digest the mixture. After a few hours, the food becomes a liquid and moves into the small intestine. This makes it easier for the intestine to absorb the substances that the body needs for energy.

Stomach cancer begins when some of the cells in its lining take on an abnormal appearance and begin to divide without control or order. If left untreated, these cancer cells can grow through the stomach wall, and they can spread to nearby organs, or to nearby lymph nodes. Through the lymphatic system, the cancer cells can spread to distant areas of the body, including the lungs and the ovaries.  

About stomach cancer

The stomach is a muscular bag in your abdomen that digests the food you eat. The stomach lining produces a strong acid to help break down the food and protect you from harmful bacteria. The food is also broken down by the churning action of the stomach. The food then passes into the duodenum, the first part of the small intestine.

Most stomach cancers form a tumour (lump) or ulcer in the inner lining of the stomach. Less commonly, the cancer spreads along the stomach wall without forming a lump.

In the early stages, stomach cancer stays within the stomach lining or stomach wall. However, the cancer cells can spread into neighbouring organs. This is called localised spread.

Sometimes the cancer cells can break away and travel to other parts of the body in the bloodstream and lymph system (the lymphatic system which makes up part of your body's immune system). This is called metastasis.

Types of stomach cancer

About nine in 10 stomach cancers are called adenocarcinomas. The cancer starts in the glandular tissue cells which produce mucous and stomach juices and make up part of the stomach lining.

Other rare types of stomach cancers include:

• squamous cell carcinomas - the cancer starts in the squamous cells, which are skin-like cells and make up part of the stomach lining
• soft tissue sarcomas - the cancer starts in the muscle layer of the stomach wall
• lymphomas - the cancer starts in the lymphatic system
• carcinoid tumours - the cancer starts in the neuroendocrine system (the system of glands throughout your body which produce hormones)

Symptoms of stomach cancer

Early stomach cancer can cause very mild indigestion-like symptoms such as:

• heartburn and burping
• feeling bloated after eating only a small meal
• losing your appetite
• persistent stomach pain
• feeling or being sick
• difficulty swallowing

As the cancer grows, other symptoms may include:

• weight loss
• vomiting blood
• dark coloured faeces
• tiredness and anaemia (when you have too few red blood cells or not enough haemoglobin in your blood) caused by blood loss
• swelling or a lump in the stomach area

These symptoms aren't always due to stomach cancer but if you have them, visit your GP.

Causes of stomach cancer

Doctors don't fully understand why stomach cancer develops. However, certain factors make stomach cancer more likely.

• Age - it's most common around age 60.
• Gender - men are twice as likely to develop it as women.
• Helicobacter pylori infection - if it causes inflammation of the stomach lining (gastritis), indigestion and stomach ulcers, it could double your risk of stomach cancer.
• Diet - too much salt, red meat and foods that are smoked or which contain preservatives known as nitrosamines may increase the risk of stomach cancer.
• Family history.
• Type A blood group.
• Smoking and drinking too much alcohol.
• Atrophic gastritis - this condition causes the lining of the stomach to waste away.
• Acid reflux, also known as gastro-oesophageal reflux disease (GORD).
• Pernicious anaemia - this is a condition where the body doesn't absorb enough vitamin B12 from the diet.
• Being overweight.

Diagnosis of stomach cancer

The earlier stomach cancer is diagnosed, the better your chances of recovery. If you develop any of the symptoms listed above and you are over 45, visit your GP. Your GP will ask about your symptoms and examine you. You may then be referred to a doctor specialising in cancer (an oncologist).

You may have the following tests to confirm diagnosis.

• Blood tests - to check for anaemia and liver function.
• Stomach examination - your doctor may use a special endoscope to look inside your stomach. See related factsheet on gastroscopy.
• Biopsy - a sample of tissue is removed and sent to a laboratory for diagnosis.
• Barium meal X-ray - you will be asked to swallow a liquid containing a special dye (barium) that shows up on X-rays. Barium will show up any unusual growths in the stomach lining.
• Scans - these may include ultrasound, MRI or CT scans. These are done to check the stomach, liver, and surrounding lymphatic system to see if the cancer has spread.

Treatment of stomach cancer

Treatment depends on the type of stomach cancer and how far it has spread. Your doctor will discuss your treatment options with you. There are three main treatments for stomach cancer.

Surgery

Surgery (including the use of lasers) involves removing just the affected tissue. How much surgery is needed depends on how much tissue is affected. Surgery is sometimes followed by chemotherapy or radiotherapy treatment to make sure all the cancer cells are destroyed.

Non-surgical treatment

• Chemotherapy - anti-cancer drugs are used to destroy cancer cells. They are usually injected into a vein but sometimes you may be given tablets.
• Radiotherapy - radiation is used to kill cancer cells.
• Biological therapy - special manufactured monoclonal antibodies (bevacizumab) are used to block areas on the surface of cancer cells that trigger growth. This treatment is currently being tested in clinical trials.

Prevention of stomach cancer

Simple dietary changes can reduce your risk of stomach cancer.

• Eat a healthy diet with at least five portions of fruit and vegetables a day. They contain antioxidants which are believed to prevent damage to the stomach lining.
• Cut down on processed and pickled food.
• Cut down on salt.
• Cut down on red meat.
• Don't smoke.
• Don't chew tobacco.
• Drink only in moderation.
• Keep a healthy weight - if you're overweight, regular exercise and a healthy diet can help you reduce your weight.

How cancer develops