A cancerous tumour in the lining of the stomach wall
- More common over the age of 55
- Twice as common in males
- More common in people with blood group A; sometimes runs in families
- Certain foods, smoking, and a high alcohol intake are risk factors
Worldwide, stomach cancer is one of the most common forms of cancer, accounting for about 10 per cent of all new cancer cases per year. It is a particular problem in Japan and China, possibly because of dietary factors. However, in most other countries the disease has become less common. In the UK the incidence has halved over the past 30 years, and in 2006 there were about 7,700 new cases. Stomach cancer is rare before the age of 55 but the incidence then increases with age. It is about twice as common in males. It is also more common in people of blood group A and can run in families, suggesting a genetic factor.
In most cases, stomach cancer develops in the stomach lining. The cancer may spread rapidly to other parts of the body. Early diagnosis is rare because the symptoms are usually mild, and by the time people seek medical help, the cancer has often spread.
What are the causes?
The causes of stomach cancer are not fully understood, but there are a number of factors. Chronic gastritis due to infection with the H. pylori bacterium (see Helicobacter pylori infection) increases the risk of stomach cancer. Certain diets may increase the risk, such as a diet with a high intake of salt, pickled and smoked foods, and a low intake of fresh fruit and green vegetables. Smoking and a high alcohol intake are also risk factors.
What are the symptoms?
The early symptoms of stomach cancer are mild and vague, and many people ignore them. They may include:
Discomfort in the upper abdomen.
Pain in the stomach after eating.
Loss of appetite and weight loss.
Nausea and vomiting.
In many people, iron-deficiency anaemia develops due to minor bleeding from the stomach lining. Later on, swelling may be felt in the upper abdomen.
How is it diagnosed?
Your doctor may arrange for you to have upper digestive tract endoscopy, in which a flexible viewing tube is used to examine the lining of the stomach. Tissue samples from abnormal areas of the stomach lining are tested for the presence of cancerous cells. You may also have a barium meal (see Contrast X-rays), in which a liquid barium mixture is swallowed to show the stomach clearly on an X-ray. The doctor may arrange blood tests for anaemia, which may show that there has been bleeding from the stomach lining.
If a diagnosis of stomach cancer is confirmed, further investigations, such as CT scanning and blood tests, may be performed to check whether the cancer has spread to other organs (see Staging cancer). Endoscopic ultrasound, in which a probe is passed into the stomach to look for evidence of tumour spread, may also be performed.
What is the treatment?
The only effective treatment for stomach cancer is early surgery to remove the tumour. However, in about 8 in 10 cases the cancer has already spread too widely to be operable. The operation involves the removal of part or all of the stomach. The surrounding lymph nodes are also removed since they are possible sites of cancer spread. In some cases in which the cancer has spread to other parts of the body, surgery may help to improve life expectancy, but in other cases surgery is carried out to relieve the symptoms rather than to attempt a definitive cure. Chemotherapy may also be used, either to slow the progress of the disease and relieve symptoms if the cancer is not operable, or to reduce the risk of the cancer recurring after surgery. Radiotherapy is not commonly used to treat stomach cancer but may some-times be used to shrink the tumour or to help relieve symptoms. Strong painkillers may also be given to relieve severe discomfort.
What is the prognosis?
If detected and treated early, stomach cancer has a good cure rate. Some countries in which stomach cancer is common, such as Japan, have efficient screening programmes to detect the cancer early, and in Japan about 90 per cent of people are alive 5 years after diagnosis. In the UK, stomach cancer tends to be diagnosed at a later stage and the survival rate is poorer. However, it has risen steadily over the past 30 years, and now about 35 per cent of people survive for at least 1 year after diagnosis and 15 per cent survive for at least 5 years.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.