Gastric cancer (stomach cancer): symptoms, tests and treatment in the UK

The stomach sits in the upper left part of the abdomen. It stores food and starts to break it down so the body can absorb it later in the digestive tract. Cancer Research UK explains that stomach cancer, also called gastric cancer, begins when abnormal cells in the stomach start to divide in an uncontrolled way.

The type of cell the cancer starts in determines the type of tumour. The most common is adenocarcinoma, which arises from the gland cells of the stomach lining. Other, rarer tumours of the stomach exist and are handled by specialist teams, so a pathology report after a biopsy is an important part of the diagnosis.

Stomach cancer can grow quietly. Because the early signs overlap with everyday digestive complaints, people sometimes live with them for months before being investigated. That is the main reason NHS advice emphasises acting on symptoms that persist or change rather than waiting for something dramatic.

The NHS notes that there are many possible symptoms, and they can affect digestion or the body more generally. None of them proves cancer. Most people with these symptoms have a more common explanation, such as reflux, gastritis or an ulcer, but they still deserve a proper check.

• Heartburn or acid reflux that is new, worse or different from usual.

• Problems swallowing (dysphagia).

• Feeling or being sick, or burping a lot, as with indigestion.

• Feeling full very quickly when eating.

• Loss of appetite, or losing weight without trying.

• Pain or a lump at the top of the tummy.

• Feeling tired or having no energy, and darker than usual poo.

The NHS advises seeing a GP if you have problems swallowing, a lump in your tummy, weight loss that is not explained by diet or exercise changes, other symptoms that get worse or do not improve after 3 weeks, or an existing digestive condition whose symptoms are not settling after 3 weeks of your usual treatment.

It also says to get advice from NHS 111 if you have been vomiting for more than 2 days. If you are vomiting blood, or your vomit looks like coffee grounds, or you have sudden severe tummy pain, that is an emergency: call 999 or go to A&E.

People who already live with reflux sometimes get used to their symptoms. The NHS specifically warns that it is important to be checked if your symptoms change, get worse or no longer feel normal for you.

Anyone can develop stomach cancer and the cause is often not clear. Beyond the factors listed in the key facts, the NHS says many stomach cancers are linked to lifestyle. Cancer Research UK adds that older age, smoking and infection with Helicobacter pylori are among the recognised risk factors.

H. pylori is a common stomach bacterium that usually causes no trouble, but in a small number of people long-standing infection contributes to stomach cancer. Guts UK puts this at between 1 and 3 people in 100 and suggests that first-degree relatives of someone with stomach cancer are tested for the bacterium; this is worth raising with a GP if it applies to you.

The NHS suggests ways to reduce the risk: stop smoking, lose weight if you are overweight, cut down on salt, keep alcohol to no more than 14 units a week, eat at least 5 portions of fruit and vegetables a day, and use protective clothing and masks if your work exposes you to harmful chemicals, as in the rubber industry or coal mining.

A GP will usually ask about your symptoms, may feel your tummy and may request blood tests. Cancer Research UK says that if your symptoms could be due to stomach cancer, your GP should refer you to a specialist or arrange tests. The NHS adds that this may be an urgent referral, which does not mean you definitely have cancer.

The key test is a gastroscopy, a type of endoscopy. A long, thin, flexible tube with a camera is passed through the mouth and throat into the stomach, and a small tissue sample may be taken for laboratory examination. The NHS says it takes around 10 to 15 minutes, should not be painful but may be uncomfortable, and that local anaesthetic throat spray or sedation can be offered. Results of the gastroscopy and biopsy should normally be available within 2 weeks.

If cancer is confirmed, further tests find out the size and stage. The NHS lists ultrasound scans (sometimes from inside the body using an endoscope), CT scans and PET scans, and sometimes a small keyhole operation called a laparoscopy to look inside the abdomen. You may not need every test.

According to the NHS, treatment depends on the type and size of the cancer, where it is, whether it has spread and your general health. It usually includes surgery and chemotherapy and may also include radiotherapy and targeted medicines or immunotherapy.

The NHS says recovery from surgery for stomach cancer can take a long time and that your team will help you manage side effects, including changes to your diet. Having part or all of the stomach removed changes how much you can eat at once, so dietitians are normally part of the care team.

You will have regular check-ups and scans during and after treatment, and the NHS encourages you to contact your specialist team if you have symptoms or side effects that worry you rather than waiting for the next appointment. A clinical nurse specialist is usually your main point of contact.

If the cancer cannot be cured, the NHS explains that the aim of treatment becomes limiting the cancer and its symptoms and helping you live longer. A palliative care or symptom control team works alongside the cancer team to keep you comfortable and to support the people close to you. Hearing this can be very hard, and talking therapies or charity support lines are there for exactly that reason.

For suspected stomach cancer, the NHS route runs from the GP to an urgent specialist referral, a gastroscopy, then a multidisciplinary team that agrees the treatment plan. Cancer treatment on the NHS is free at the point of use, and the clinical nurse specialist coordinates the pathway.

Some people also choose to see a private upper gastrointestinal specialist, often to speed up the first appointment or endoscopy or to obtain a second opinion. The practical differences tend to be in waiting time and in choice of consultant and hospital, not in the underlying tests, which are the same. Complex cancer surgery is concentrated in specialist centres in both sectors, and many people move between NHS and private care at different stages. Ask any provider which team will be responsible for each stage and who you should contact if symptoms change.