Stomach cancer

24 min read

What is stomach cancer?

Stomach cancer is when an abnormal groups of cells, known as a tumour, develops inside the stomach. It’s also know as gastric cancer.

The initial symptoms of stomach cancer are vague and easy to mistake for other conditions. They include:

  • indigestion and /or heartburn
  • stomach ache
  • feeling very full after meals

Symptoms of advanced stomach cancer can include:

  • blood in your stools, or black stools
  • loss of appetite
  • weight loss

Read more about the

symptoms of stomach cancer

As the symptoms are similar to many other less serious conditions, it can often be advanced by the time it’s diagnosed. Because of this, it is important to get any possible symptoms of stomach cancer checked out as soon as possible.

Types of stomach cancer

There are different types of stomach cancer. 95% develop in the cells of the stomach lining.and are known as adenocarcinoma of the stomach.

Less common types include:

  • lymphoma of the stomach, which develops in the lymphatic tissue (tissue that drains away fluid and helps fight infection)
  • gastrointestinal stromal tumours (GISTs) - in the muscle or connective tissue of the stomach wall


Most cases of stomach cancer are treated using surgery to remove some or all of the stomach. This is known as a gastrectomy.

You will still be able to eat normally after a gastrectomy but you will most likely have to adjust the size of your portions.

Chemotherapy is also commonly used before surgery to help shrink the tumour and sometimes after surgery to help prevent the cancer from returning.

Many cases of stomach cancer can not be completely cured, but it is still possible to relieve symptoms and improve quality of life using radiotherapy and in some cases also chemotherapy and surgery.

Read more about

treating stomach cancer

Who’s at risk

The exact cause of stomach cancer is still unclear, although a number of risk factors have been identified. These include:

  • being aged 60 or over
  • being male
  • being white
  • eating a unhealthy diet that is low in fruit and vegetables
  • having a type of bacteria infection known as H. plyori inside your stomach

Read more about the possible

causes and risk factors for stomach cancer

Living with stomach cancer

Living with stomach cancer and then coming to terms with the after-effects of surgery but there are a range of services that can provide social, psychological and in some cases, financial support.

Read more about

living with stomach cancer

Who is affected

Stomach cancer is a relatively uncommon cancer with around 6,000 new cases diagnosed each year. Men are twice as likely to be affected then women and, as mentioned, it is primarily a disease of aging.

The average age at diagnosis for men is 70 years and for women is 74 years.

Stomach cancer symptoms

There are several symptoms of stomach cancer.

However, as they are similar to those of many other less serious conditions, stomach cancer can sometimes be difficult to recognise. For this reason, it can often be quite advanced by the time it’s diagnosed.

Early symptoms of stomach cancer may include:

  • persistent
  • trapped wind and frequent burping
  • heartburn
  • feeling full very quickly when eating
  • feeling bloated after eating
  • pain in your stomach or breastbone (sternum)
  • difficulty swallowing (
  • feeling sick
  • vomiting (which may be streaked with blood)

Alarm symptoms

It is important to get any possible symptoms of stomach cancer checked out as soon as possible.

You should see your doctor as soon as possible if you experience any of the alarm symptoms listed below.

You experience difficult swallowing

You experience indigestion in combination with one or more of the following:

  • weight loss
  • being sick
  • anaemia
    (a reduction in red blood cells that can cause you to feel tired and out of breath)

You are over 55 and you develop persistent indigestion

You develop indigestion and you have one or more of the following in your medical history:

  • a family history of stomach cancer
  • previous surgery for
    stomach ulcers
  • Barrett’s oesophagus - a condition where abnormal cells develop on the inner lining of the oesophagus
  • pernicious anaemia
    – a condition where your stomach is unable to absorb vitamin B12 from food
  • dysplasia – dysplasia are an abnormal collection of cells that are not actually cancerous but could turn cancerous at a later date
  • gastritis - inflammation of the stomach lining You experience yellowing of your eyes and skin (
    You develop a noticeable swollen mass in your upper abdomen

Advanced stomach cancer

The symptoms of more advanced stomach cancer may include:

  • blood in your stools, or black stools
  • loss of appetite
  • weight loss
  • tiredness
  • lumpiness in your stomach (caused by a build-up of fluid)
  • anaemia

Stomach cancer causes

Cancer begins with a change in the structure of DNA. DNA provides our cells with a basic set of instructions, such as when to grow and reproduce.

A change in DNA structure is known as a mutation, and it can alter the instructions that control cell growth. This means that the cells continue to grow instead of stopping when they should. This causes the cells to reproduce in an uncontrollable manner, producing a lump of tissue called a tumour.

Exactly what triggers the changes in DNA that lead to stomach cancer and why only a small number of people develop stomach cancer is still uncertain.

However, there is evidence that there are a number of significant risk factors for stomach cancer.

These are discussed below.


Your risk of getting stomach cancer increases with age. Most cases occur in people over the age of 55 with the average age at diagnosis being around 70.


Men are twice as likely as women to develop stomach cancer. It is unclear why this is the case.


Smokers may be twice as likely to develop stomach cancer compared with non-smokers. This is because some tobacco smoke will always be swallowed when you inhale and end up in your stomach and tobacco contains many harmful substances that can damage cells.

The more you smoke and the longer you have been smoking the bigger on risk. On averages smokers are 1 ½ times more likely to get stomach cancer than non-smokers.

H. pylori infection

H. pylori is a common type of bacteria that is thought to be present in up to half of the world’s population.

In most people they are harmless but in some people an H pylori infection can cause conditions such

stomach ulcers
, recurring bouts of
or chronic inflammation of the stomach lining (atrophic gastritis).

Research has found that people with severe atrophic gastritis have the highest risk of developing stomach cancer, although this risk is still very small.


A diet rich in pickled vegetables (such as pickled onions or piccalilli), salted fish, salt in general and smoked meats (such as pastrami or smoked beef) increases your risk of stomach cancer.

Countries where this type of diet is popular such as Japan have much higher rates of stomach cancer than would normally be expected.

Family history

You are more likely to develop stomach cancer if you have a close relative with the condition, such as one of your parents or your brother or sister. One study estimated that if one of these family members develops stomach cancer this increases your risk by around 1 ½ .

It is not fully understood why this is, but it is possible that it is due to family members having certain risk factors in common.

In around 1 in 50 cases of stomach cancer, testing has found that people share a genetic mutation (where the instructions contained in all living cells become scrambled in some way) in a gene known as the E-cadherin gene.

Research into stomach cancer has also shown that you may be more at risk of getting the condition if you have the blood type A. Your blood type is passed on from your parents, so this could be another way in which family history may increase your risk of developing stomach

There is also a condition that runs in families called familial adenomatous polyposis (FAP), which may make developing stomach cancer more likely. FAP causes small growths, called polyps, to form in your digestive system, and it is known to increase your risk of developing bowel cancer.

Having another type of cancer

If you have had another type of cancer, such as cancer of the oesophagus (gullet), or non-Hodgkin's lymphoma (cancer that develops in the white blood cells in your immune system), you have an increased risk of developing stomach cancer.

There are also other cancers that can make developing stomach cancer more likely, for both men and women. If you are a man, your risk of stomach cancer is increased if you have had cancer of the prostate, bladder, bowel or testicle. If you are a woman, your risk of developing stomach cancer increases if you have had cancer of the ovary, breast or cervix.

Certain medical conditions

Having certain medical conditions can also increase your risk of developing stomach cancer.

These are outlined below.

  • Oesophagitis
    : inflammation of your gullet (oesophagus) caused by a reflux of stomach acid.
  • Gastroesophageal reflux disease (GORD)
    : a severe form of oesophagitis.
  • Pernicious anaemia
    : a vitamin B12 deficiency, which occurs when you body cannot absorb it properly.
  • Peptic stomach ulcers
    : an ulcer in your stomach lining, often caused by H pylori infection.
  • Barrett's oesophagus: abnormal changes to the cells in the gullet. This condition also increases your risk of developing cancer of the oesophagus.

Surgery affecting the stomach

If you have had surgery to your stomach, or to a part of your body that affects your stomach, you may be more likely to develop stomach cancer.

This can include surgery to remove part of your stomach (known as a partial gastrectomy), surgery to remove part of your vagus nerve (the nerve that carries information from your brain to organs such as your heart, lungs, and digestive system) or surgery to repair a stomach ulcer.

How does stomach cancer spread

There are three ways that stomach cancer can spread:

  • directly – the cancer can spread out of the stomach and into nearby tissues and organs, such as the pancreas, colon and small intestine
  • via the lymphatic system - lymphatic system is a series of glands (or nodes) that are located throughout your body, similar to the blood circulatory system; glands produce many specialised cells that are needed by your immune system to fight infection
  • via the blood – which in many cases will see the cancer spread from the stomach into the liver

Stomach cancer that spreads to another part of the body is known as metastatic stomach cancer.

Stomach cancer treatment

Many hospitals use multidisciplinary teams (MDTs) to treat stomach cancer. MDTs are teams of specialists that work together to make decisions about the best way to proceed with your treatment.

Members of your MDT may include:

  • a surgeon
  • a clinical oncologist (a specialist in the non-surgical treatment of cancer)
  • a pathologist (a specialist in diseased tissue)
  • a radiologist (a specialist in radiotherapy)
  • a dietician
  • a social worker
  • a psychologist
  • a specialist cancer nurse, who will usually be your first point of contact between yourself and the rest of the team

Your treatment plan

When deciding what treatment is best for you, your doctors will consider:

  • the stage and grade of your cancer (how big it is and how far it has spread)
  • your general health

Feel free to discuss your treatment with your care team at any time and to ask any questions.

The main treatments for stomach cancer are:

You may have one of these treatments or a combination. The type of treatment or the combination of treatments will depend on how the cancer was diagnosed and at what stage and grade it is.

The first aim of treatment, where possible, is to completely eliminate (remove) the tumour and any other cancerous cells in your body. If this is not possible, your doctors will focus on trying to prevent your tumour from getting any bigger and causing any further harm to your body. This is usually done using a combination of surgery and chemotherapy.

In some cases, it is neither possible to eliminate the cancer or slow down its progression. In this case, your treatment will aim to relieve your symptoms and to make you as comfortable as possible. This is usually done using radiotherapy. In some cases, surgery and chemotherapy may be used.

A new medication called trastuzumab can also be used to treat some types of advanced stomach cancer.

Your healthcare team will discuss with you which treatments are most suitable.


If you are diagnosed with stomach cancer at an early stage, you may require surgery to try to remove the cancer.

However, if your cancer has spread beyond your stomach, it may not be possible to remove it completely through surgery. If this is the case, you may still have surgery to remove any cancer that is blocking your stomach, to ease your symptoms. This will depend on balancing the control of your symptoms and the risks and side effects of undertaking a major surgical procedure.

After surgery for stomach cancer

Any kind of surgery for stomach cancer will involve a large operation and a long recovery time. If you have stomach cancer surgery, you will usually have to stay in hospital for around two weeks. You will also need several weeks to recover at home.

Surgery to remove stomach cancer

If you have surgery to remove the cancer in your stomach, and depending on where in your stomach the cancer is, it is likely that you will need to have part or all of your stomach removed.

Surgery to remove part of your stomach is known as a partial gastrectomy, and surgery to remove all of your stomach is known as a total gastrectomy. In some cases, your surgeon may also remove part of your oesophagus (gullet), as well as the whole of your stomach, which is known as an oesophagogastrectomy.

During both of these operations, your surgeon will also remove the lymph nodes (tissues that remove bacteria from your body) nearest to the cancer in your stomach. It is possible that your stomach cancer may have spread to these lymph nodes, so removing them helps to prevent the cancer from recurring.

Partial gastrectomy

If your cancer is in the lower part of your stomach, you may have a

partial gastrectomy
, in which only part of your stomach is removed. This means that the lower part of your stomach will be removed and, afterwards, your stomach will be smaller than it was before surgery. However, the operation will not affect the top part of your stomach, where your oesophagus (gullet) feeds into it.

Total gastrectomy or oesophagogastrectomy

If your cancer is in the middle or at the top of your stomach, you may need to have a

total gastrectomy
, where the whole of your stomach is removed. If the cancer is close to the end of your oesophagus (gullet), where it meets your stomach, you may also need to have part of your gullet removed. This kind of surgery is known as an oesophagogastrectomy.

If you have a total gastrectomy, your stomach will be removed and the end of your gullet will be joined to the top of your duodenum (the top part of your small intestine). If you have an oesophagogastrectomy, your stomach and the end of your gullet will be removed, and the remaining part of your gullet will be joined to your duodenum.

Surgery to ease your symptoms

If your stomach cancer has spread beyond your stomach, it may not be possible to remove it through surgery.

However, if you have a large amount of cancer in your stomach, it can cause a blockage which prevents food from being properly digested. A blocked stomach can cause symptoms such as stomach pain, vomiting, and feeling very full after eating.

If you have a blocked stomach, there are a few options which can be considered.

  • You may have a stent inserted where the blockage is. A stent is a plastic or wire mesh tube that is inserted during an endoscopy. After insertion, the stent will expand in place and open up the stomach.
  • You may be able to have a partial or total gastrectomy to reduce the blockage and improve your symptoms.
  • You may have bypass surgery. In a bypass operation, the part of your stomach above the blockage is joined to your duodenum (the top part of your small intestine), leaving the blocked part of your stomach out of your digestive system. This allows food to move through the unblocked part of your stomach and into your intestines, without coming into contact with the blockage.


Chemotherapy is a specialist treatment for cancer that uses medicines that can stop the growth of cancer cells. These medicines are known as cytotoxic, which means they target rapidly growing cancer cells, stopping them from dividing and multiplying. As it circulates through your system, the medicine can target cancer cells in your stomach, as well as any that may have spread elsewhere in your body.

You may have chemotherapy for stomach cancer before surgery to reduce the amount of cancer that your operation has to remove. You may also have chemotherapy after surgery to destroy any remaining cancer cells, and prevent the cancer from recurring.

Chemotherapy can also be used to slow the progression of cancer and ease the symptoms of more advanced stomach cancer, which may not be suitable for surgery.

If you need to have chemotherapy, the medicine may be given as tablets or intravenously (by injection or a drip through a vein directly into your bloodstream) or a combination of both.

Intravenous chemotherapy is usually given in hospital, while oral chemotherapy is taken at home.

Chemotherapy is often given in cycles, each lasting about three weeks.

Alternatively, the medicine may be fed into your system through a small pump, which gives you a constant low dose of chemotherapy over a period of a few weeks or months. The pumps are portable and can be worn at home, which can mean fewer trips to hospital.

Side effects of chemotherapy

Chemotherapy works by preventing cells, such as those that are cancerous, from growing rapidly.

However, there are other cells that occur naturally in your body that also divide and multiply rapidly, including hair follicles and red and white blood cells.

Chemotherapy destroys these non-cancerous cells, which can cause different side effects including:

  • hair loss
  • feeling sick (nausea) and being sick (vomiting)
  • loss of appetite
  • sores around your mouth
  • anaemia (this may cause tiredness and breathlessness brought on by a lack of red blood cells)
  • increased vulnerability to infection

If you need to have chemotherapy, the side effects you experience will depend on the type of cytotoxic medicine that you take, the number of treatment sessions you need to have and your individual reaction to the treatment. You will be told who to contact if you are experiencing serious side effects from chemotherapy and it is very important that this contact information is recorded carefully.

If you experience nausea and vomiting as a result of chemotherapy, you may be able to take anti-sickness medication to counter it. This may be given intravenously (by injection directly into your bloodstream) at the same time as your chemotherapy.

The side effects of chemotherapy will only last for as long as your course of treatment lasts. Once your treatment is over, the rapidly growing cells that occur naturally in your body will repair themselves. This means that your hair will grow back, although it might look or feel different from how it did before your chemotherapy. For example, it may be a slightly different colour, or be softer or curlier than before.


Radiotherapy uses high energy X-rays and, like chemotherapy, works by targeting rapidly growing cancer cells. Radiotherapy is not often used to treat stomach cancer because there is a risk that other organs that are very close to your stomach might be damaged by the treatment.

However, you may need to have radiotherapy for stomach cancer if it’s advanced and causing bleeding or pain.

In some cases, following surgery, you may have chemotherapy and radiotherapy together, to help to prevent the stomach cancer from recurring.

However, this type of treatment is still being researched and, if it is offered to you, it is likely to be as part of a clinical trial. Read more about [clinical trials for stomach cancer].

If you need to have radiotherapy, your treatment will begin several months after your surgery or chemotherapy to give your body a chance to recover. It is a painless procedure in which you lie under a radiotherapy machine while it directs radiation at your stomach. You will be positioned by your radiographer (a specialist in radiotherapy) so that the machine targets only the cancer cells and avoids as much of your healthy tissue as possible.

It is likely that you will have radiotherapy sessions five days a week, for about five weeks. Each session will only last a few minutes. The radiation does not stay in your system afterwards, and it is perfectly safe to be around others in between your treatments.

Side effects of radiotherapy

If radiotherapy is being used to relieve symptoms of advanced stomach cancer then it is usually given at a relatively low dose so you should not experience any significant side effects.

If it is being given in combination with chemotherapy then the dosage will be higher and you may experience the following side effects:

  • nausea, with or without vomiting
  • diarrhoea
  • tiredness
  • stomach pain
  • irritation and darkening of your skin where the treatment takes place


Trastuzumab (sold under the brand name Herceptin) is a medication that was first used to treat breast cancer and has now been found to be useful in treating some cases of advanced stomach cancers.

Some stomach cancers are stimulated by a type of protein called human epidermal growth factor receptor 2 (HER2). So trastuzumab works by blocking the effects of the HER2 protein.

This does not cure stomach cancer but it can slow its growth and increase survival time.

If you are diagnosed with advanced (stage 4) stomach cancer and testing shows you have high levels of the HER2 protein in the cancerous cells then your doctors may recommend you are treated with a combination of chemotherapy and trastuzumab.

Trastuzumab is given intravenously, through a drip, and you will have the treatment in hospital.

Each treatment session takes up to one hour and you will usually need a session once every three weeks.

Trastuzumab can cause side effects, including heart problems. This means that it maybe not suitable if you have a heart problem, such as angina, uncontrolled high blood pressure (hypertension) or heart valve disease. If you need to take trastuzumab, you will need regular tests on your heart to make sure it is not causing any problems.

Other side effects of trastuzumab may include:

  • an initial allergic reaction to the medication, which can cause nausea, wheezing, chills and fever
  • diarrhoea
  • tiredness
  • aches and pains

Read more about


Living with cancer

Stomach cancer

Recovery and follow up


Getting back to normal after surgery can take time. It is important to take things slowly and give yourself time to recover. During this time, avoid lifting things (such as children or heavy shopping bags) and heavy housework. You may also be advised not to drive.

Some other treatments, particularly radiotherapy and chemotherapy, can make you very tired. You may need to take a break from some of your normal activities for a while. Do not be afraid to ask for practical help from family and friends.


After your treatment has finished, you will be invited for regular check-ups, usually every three months for the first year. During the check-up, your doctor will examine you and may do blood tests or X-rays to see how your cancer is responding to treatment.

Diet after surgery

If you have had a partial gastrectomy, you will only be able to eat small amounts of food for a while after your operation. This is because your stomach will not be able to hold as much food as it could before the surgery, and your body will need to adjust to its new stomach capacity. You should gradually be able to increase the amount that you eat as your stomach begins to expand.

If you have surgery to remove all of your stomach, it may be quite some time before you can eat normally again. As with a partial gastrectomy, you will only be able to eat small amounts of food until your body adjusts. You may have to eat little and often, and make changes to the types of food that you eat. Your cancer team will be able to advise you about what and when you should eat.

Having surgery to remove your stomach also means that you will need to have regular injections of vitamin B12. This is normally absorbed through your stomach from the food that you eat, and is needed to help prevent anaemia (fatigue and weakness caused by a lack of red blood cells) and nerve problems.

Relationships with others

It is not always easy to talk about cancer, either for you or your family and friends. You may sense that some people feel awkward around you or avoid you. Being open about how you feel and what your family and friends can do to help may put them at ease. But do not feel shy about telling them that you need some time to yourself, if that is what you need.

Talk to others

If you have questions, your doctor or nurse may be able to reassure you. You may find it helpful to talk to a trained counsellor or psychologist, or to someone at a specialist helpline. Your doctor surgery will have information on these. Some people find it helpful to talk to other people who have stomach cancer, either at a local support group or in an internet chatroom.

Caring for someone with stomach cancer

Being a carer is not an easy role. When you are busy responding to the needs of others, it can deplete your reserves of emotional and physical energy and make it easy for you to forget your own health and mental wellbeing. Research on carers’ health shows that high numbers of carers suffer health effects through caring. And if you are trying to combine caring with a paid job or looking after a family, this can cause even more stress.

But putting yourself last on the list does not work in the long-term. If you are caring for someone else, it is important to look after yourself and get as much help as possible. It is in your best interests and those of the person you are caring for.

Look after your health

Eat regularly and healthily. If you do not have time to sit down for every meal, try to make time to sit down for at least one of your day's meals. Instead of relying on fast food snacks, go for healthier options, such as fruit.

Look after your emotional health

It is understandable if there are times when you feel resentful and then guilty for feeling like this. Combine that with exhaustion, isolation and worries about the person you are caring for. But you are human and those feelings are natural.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.