Stomach cancer

Expert reviewer, Mr Stephen Pollard, Consultant Surgeon
Next review due November 2023

Stomach cancer happens when cells in your stomach grow in an abnormal and uncontrolled way. It’s also known as gastric cancer.

It can be possible to cure stomach cancer if it’s found at an early stage. If it’s found at an advanced stage, treatment can help control the cancer, ease your symptoms and improve your quality of life.

About stomach cancer

In the UK, around 6,600 people get stomach cancer each year. This makes it one of the less common cancers in the UK, and the number of people getting it has been steadily decreasing. It’s more common in other areas of the world – for example, Eastern Asia – probably because of differences in diet and lifestyle.

Early symptoms of stomach cancer may be quite vague and similar to indigestion. This means that many people with stomach cancer don’t find out until the cancer is quite advanced. Without treatment, stomach cancer can spread to other parts of your body including organs such as your liver. When cancer spreads through the body, the process is called metastasis.

Most (more than nine out of 10) stomach cancers start in gland cells in the lining of your stomach. These are called adenocarcinomas. Our information here is about this type of stomach cancer.

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Causes of stomach cancer

Stomach cancer is likely to be due to a combination of different factors. But it’s often linked to lifestyle, including diet. Although it’s possible to develop it at a younger age, stomach cancer is more common in older people – most people who get it are over 55. It’s also more common in men than women.

You're also more likely to develop stomach cancer if you:

  • have a long-term stomach infection with a type of bacteria called Helicobacter pylori (H. pylori)
  • have pernicious anaemia – where your body doesn't absorb enough vitamin B12 from your diet
  • have a diet high in salt or preserved foods such as smoked, cured or pickled foods, or low in fruit and vegetables
  • smoke
  • drink a lot of alcohol 
  • are overweight or obese 
  • have acid reflux, also known as gastro-oesophageal reflux disease (GORD)
  • are blood group A

A small number of people who develop stomach cancer also have a family history of the disease.

Having any of these risk factors doesn’t mean that you will definitely get stomach cancer – but they increase your chances of developing it. Similarly, you can still develop stomach cancer without having any of these risk factors.

Symptoms of stomach cancer

Symptoms of stomach cancer can be quite vague in the early stages. For many people, indigestion is one of the first symptoms.

Other symptoms of stomach cancer may begin to happen as the cancer advances. These can include:

  • pain in your abdomen (tummy)
  • losing weight without trying
  • losing your appetite
  • feeling unusually full after eating
  • difficulty swallowing
  • feeling sick or being sick
  • blood in your poo, which can make it look black
  • feeling tired and breathless, due to anaemia (a reduced number of red blood cells)

Many of these symptoms are often caused by other less serious problems or conditions such as gallstones, ulcers or reflux. Contact your GP if you have new, unusual symptoms for you – or if they don’t go away after three weeks. You should also contact your GP if you regularly take indigestion medicines but they seem to have stopped working. You should always seek medical help if you have difficulty swallowing.

Diagnosis of stomach cancer

Your GP will ask about your symptoms and examine you. They’ll also ask you about your medical history and will arrange for you to have blood tests.

If your GP thinks you need further investigations, they may refer you for a test called a gastrointestinal endoscopy (also called a gastroscopy). The test involves passing a narrow, flexible, tube-like telescopic camera called an endoscope down your throat to look inside your stomach. The endoscopist who carries out the test may remove small samples of tissue (biopsies) from any abnormal areas of your stomach at the same time. Any samples are sent to a laboratory to look for cancer cells.

If you're found to have stomach cancer, you’ll be referred to a specialist cancer doctor (oncologist) or surgeon. You’ll need further tests to find out how advanced your cancer is and if it’s spread. This process is known as staging. Tests may include:

  • a chest X-ray 
  • a whole-body CT scan 
  • a PET-CT scan (a specialist CT scan using radioactive medicine to show up potential cancer cells)
  • an endoscopic ultrasound, which combines endoscopy with ultrasound to show how deep the cancer goes
  • a laparoscopy – a small operation to look inside your abdomen, using a thin tube (a laparoscope) inserted through small cuts in your tummy

Your doctor will explain which of these tests you may need and what they involve. Be sure to ask your doctor any questions you have about your tests.

Treatment of stomach cancer

Your treatment and care will be managed by a team of doctors and other cancer specialists. They will discuss with you what treatments they recommend in your particular circumstances. Treatment will depend on the size and position of your stomach cancer, if it has spread, and if you’ve had previous surgery to your stomach. Your general health and fitness will also be taken into account, along with your own wishes about your treatment.

If you’re diagnosed with stomach cancer early, it can be easier to treat and possible to cure. Many people with stomach cancer don’t find out until it’s at a late stage and it may not be possible to cure it. If this is the case, your treatment will focus on easing your symptoms, controlling the cancer and improving your quality of life.


Surgery is the main treatment for early-stage stomach cancer because it may cure your cancer. If your cancer is very small and just in the stomach lining, you may be able to have an operation called endoscopic mucosal resection. This is when the affected areas of your stomach lining are removed through a tube passed down your throat, called an endoscope. You won’t need any cuts to your tummy for this.

For larger cancers, you may have an operation to remove part of your stomach (partial or subtotal gastrectomy) or all of your stomach (total gastrectomy). You might be able to have keyhole (laparoscopic) surgery rather than open surgery. This means your surgeon will make several smaller cuts in your abdomen to reach your stomach, instead of one larger one.

If your surgeon recommends you have surgery, they’ll explain what will happen before, during and after your operation – including potential side-effects. For more information, see our FAQs on dumping syndrome and on what you can eat and drink after surgery below.

Non-surgical treatment

Your doctor may offer you one of the following treatments as well as or instead of surgery.

  • Chemotherapy. This uses medicines to kill cancer cells. You may have chemotherapy both before and after surgery, to help cure your cancer. If you’re unable to have surgery, you may be offered chemotherapy to slow down the growth of your cancer and reduce symptoms.
  • Targeted cancer drugs. These are medicines that can seek out cancer cells and interfere with the way they grow. If your stomach cancer has spread, you may be offered a medicine called trastuzumab (Herceptin®) alongside chemotherapy. This can help control the growth of your cancer.
  • Radiotherapy. This uses radiation to destroy cancer cells. Sometimes, your doctor may offer you this alongside chemotherapy after surgery. It’s sometimes used to control symptoms if you have advanced cancer.

Prevention of stomach cancer

Over half of stomach cancers are preventable. You can control some of the risk factors for stomach cancer by making changes to your lifestyle. This may reduce your risk of getting stomach cancer and bring many other health benefits too. Changes you can make include the following.

  • Don’t eat too many salted, cured or preserved foods such as smoked meats and pickled vegetables.
  • If you smoke, stop.
  • Don’t drink alcohol, but if you do, cut down and only drink in moderation.
  • Keep to a healthy weight.

Help and support

Being diagnosed with stomach cancer and facing treatment can be distressing for you and your family. An important part of cancer treatment is having support to deal with the emotional aspects and practical issues, as well as the physical symptoms. Specialist cancer doctors and nurses are experts in providing the support you need – make sure you talk to them if you have any concerns.

Weight loss is a very common problem for people with stomach cancer. This is because the side-effects of the cancer and treatment can make it difficult to eat enough. Speak to your doctor, nurse or dietitian about how to make sure you’re eating well and getting any help you need.

Talking to your family and friends can help them to understand what you’re going through and how you’re feeling. Organisations and support groups that specialise in helping people with cancer can be a great source of information and support For further details of these, see our Other helpful websites section below.

Frequently asked questions

  • Dumping syndrome is a side-effect of some forms of stomach surgery. It's caused by food moving from your stomach into your small bowel more quickly than before your surgery. This can cause unpleasant symptoms straight after eating a meal (early dumping syndrome) or a few hours later (late dumping syndrome).

    Early dumping syndrome is due to your bowel drawing in more water quickly to dilute your food. This causes a sudden drop in your blood pressure which can make you feel faint and dizzy. You might have abdominal symptoms too, with stomach cramps, feeling bloated or sick, and diarrhoea.

    Late dumping syndrome is due to a rapid change in your blood sugar levels. This can make you feel very shaky and you may faint.

    Most people find that their symptoms are relatively mild, and they can manage them quite easily by making some changes to how they eat. You can try:

    • eating smaller meals more often (aim to have about six small meals a day)
    • eating more slowly
    • reducing or cutting out sugary foods and milk because they can make your symptoms worse
    • reducing the amount of carbohydrates you have, and eating more protein and fats instead
    • lying down for 30 minutes after meals
    • having drinks between meals rather than during them, and avoiding soup and very liquid foods

    Your doctor, nurse or dietitian can give you more advice about how to manage your symptoms.

  • It will take time for your body to recover after stomach cancer surgery. You’ll see a dietitian while you’re in hospital, who will go through with you what you’ll be able to eat and when. You’ll be able to contact them when you get home too.

    In the first day or so after your operation, you won’t be able to eat or drink at all. You’ll have a drip to give you fluids and sometimes a feeding tube into your bowel to help you get the right nutrition. You’ll usually be able to start having sips of water within a day or two, and can start building up to eating small amounts within a week or so.

    As you recover, you may feel full after small amounts of food, and it’s likely that you’ll lose some weight. Some foods may make you feel sick or give you diarrhoea or indigestion. Try to keep track of what foods cause you problems, so you know to avoid these. Your nurse or dietitian may be able to give you medication to help with these problems too. Over time, your body will start to adjust so that you may be able to manage bigger portions and different types of food.

    After stomach cancer surgery, you may not be able to absorb certain vitamins and minerals, such as iron, folate and calcium, as well as before. Your doctor will keep an eye on whether you’re getting enough of these, and if necessary, you may need to take supplements. If you’ve had all or part of your stomach removed (a total gastrectomy), you’ll need regular injections of vitamin B12 (usually every three months).

    It’s important that you eat well during and after treatment for cancer. If you have any concerns, talk to your doctor, nurse or dietitian.

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  • Reviewed by Pippa Coulter, Freelance Health Editor, November 2020
    Expert reviewer, Mr Stephen Pollard, Consultant Surgeon
    Next review due November 2023