Published by Bupa's health information team, April 2008.
This factsheet is for people who have stomach cancer, or who would like information about it.
In the UK, stomach, or gastric, cancer is the seventh most common cancer. About 8,000 people are diagnosed with stomach cancer each year. It's about twice as common in men as it is in women. More than nine in 10 people diagnosed with stomach cancer are over the age of 55.
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The stomach is a muscular bag in your abdomen (tummy) that digests the food you eat. The stomach lining produces a strong acid to help digest 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.

The different parts of the digestive system
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 discrete lump. This is known as a diffuse tumour.
In the early stages, stomach cancer is contained within the stomach lining or stomach wall. However, the cancer cells can also spread into neighbouring organs. This is called localised spread. Sometimes the cancer cells can break away and travel to distant parts of the body in the blood stream and lymph system (the lymphatic system which makes up part of your body's immune system). This is called metastasis.
There are several types of stomach cancer.
Early stomach cancer can cause very mild indigestion-like symptoms. These include:
As the cancer grows, you may have other symptoms such as weight loss, vomiting blood, or passing blood in faeces. This isn't usually fresh, red blood, but dark blood. The blood loss may go unnoticed, but over a period of time, it can cause anaemia (when you have too few red blood cells or not enough haemoglobin in your blood).
Many people have the symptoms indigestion. But most of these people don't have stomach cancer. According to Cancer Research UK, only one in a million people who get indigestion under the age of 55 have stomach cancer. But you should visit your GP if you get the following symptoms:
No one knows why some people develop stomach cancer and others don't. The number of people affected varies widely between different countries. For example, stomach cancer is far more common in Japan than in the UK. There is also evidence that people from poorer backgrounds are at increased risk.
There are a many other factors that increase the risk of developing stomach cancer.
Your GP will ask about your symptoms and examine you. If he or she suspects a stomach ulcer or cancer you will need some more tests. Some of these tests are described below.
If you are diagnosed with stomach cancer your GP will refer you to an oncologist (doctor who specialises in treating cancer).
If stomach cancer is diagnosed early, it can be treated with surgery. If it hasn't spread outside the stomach, then either the whole stomach (gastrectomy) or just the affected part of it may be removed. If the cancer has spread, surgery won't cure the cancer but it can help relieve symptoms.
Chemotherapy uses medicines to destroy cancer cells. There are lots of different types of chemotherapy drugs. They are usually injected into a vein, but sometimes you can take them as tablets.
Chemotherapy drugs have a variety of side effects. These include making you feel tired or ill, or causing nausea or hair-loss. Your specialist will advise you about what side effects to expect.
Chemotherapy can be used after surgery, and sometimes before, to try and reduce the chances of stomach cancer coming back. It's often used to control the growth of the cancer and help relieve symptoms.
Radiotherapy uses radiation to destroy cancer cells. A beam of radition is targeted on cancer cells. It isn't usually used to treat stomach cancer, but it's sometimes used in combination with chemotherapy. Talk to your doctor for more information about your treatment options.
Eating a diet rich in fruit and vegetables and not smoking will reduce your risk of developing stomach problems, including cancer. Try to be aware of the symptoms of stomach cancer, and talk to your GP promptly if you think you are affected.
This information was published by Bupa's health information team and is based on reputable sources of medical evidence. It has been peer reviewed by Dr James Quekett, Bsc, MB, ChB, MRCGP, DRCOG, DFFP, General Practitioner (GP) and GP Appraiser, Gloucestershire, and by Bupa doctors. The content is intended for general information only and doesn't replace the need for personal advice from a qualified health professional.
Publication date: April 2008.