Stomach cancer is hard to investigate. You might need different types of tests to confirm it, decide what type it is, and whether it has spread. From here, your team builds your personalised stomach cancer treatment plan. It can take time, so lean on both your healthcare team and support network.
If you doctor suspects that you have stomach cancer, you may need to undergo several different tests. Your doctor will choose the best tests for you.
If you go to your doctor with symptoms like pain in your upper stomach, worsening reflux or difficulty swallowing, your doctor may perform a physical examination to check for signs of disease.
A physical examination is a check-up, where your doctor will look for things like lumps, swelling or anything else that seems unusual. They will ask you about your medical history, family history and your health habits.
Blood tests can check:
For example, CA19-9 and CEA are tumour markers linked to stomach cancer. But other health problems can also raise these markers, and some people with stomach cancer have normal levels. So, these tests alone can't tell you if you have stomach cancer.
An endoscopy (also called gastroscopy) is the main test used to diagnose stomach cancer.
An endoscope is a thin, flexible tube with a small camera on the end. While you are sedated (asleep), the doctor will slide the endoscope down your oesophagus and into your stomach to look for abnormal areas.
The doctor will also take a small tissue sample during this procedure. This is called a biopsy. The biopsy is sent to a pathologist who looks at it under a microscope to check for signs of cancer.

A laparoscopy is a small operation done whilst you're asleep under general anaesthetic. A long tube with a camera is put in through small cuts in your tummy. This lets doctors see if cancer has spread. Small tissue samples (biopsies) can also be taken during this procedure.
Several types of scans may be used to look at your stomach and nearby organs.
Results should be ready within two weeks of having the tests. Waiting can be stressful. If your symptoms get worse while waiting, contact your doctor or go to an emergency department if needed.
Even if you have been given an urgent referral, you may have to wait days or weeks for appointments and results. This is common. Any cancer growth during this waiting period is unlikely to cause additional harm if your symptoms are otherwise stable. However, it's still important to ask how long you may have to wait.
Genetic testing can provide important information about both why a cancer develops and how it might best be treated.
While genetic testing in stomach cancer is not routine, there are two main types of genetic testing that you might hear about. One looks at the genes you were born with, and the other looks at the genes within the cancer itself.
Sometimes, stomach cancer can run in families, but this is rare. Most people who get stomach cancer do not have a family link.
Genetic testing looks at your genes, which are like instructions inside your body that tell your cells how to grow and work. A small number of people may have a change (called a mutation) in one of their genes that increases their risk of stomach cancer.
If your doctor thinks your cancer might be linked to your family history, they may suggest genetic testing. This can help find out if other family members might also have a higher risk, and what steps can be taken to protect their health.
A genetic counsellor can explain what the test means for you and your family, and help you understand your options.

If you are diagnosed with advanced cancer in the stomach, oesophagus or gastro-oesophageal junction, your doctor may recommend a type of genetic test called molecular profiling.
Your doctor will send a sample of the tumour for testing in a laboratory, to see if there are certain molecules, proteins, or gene changes that can help decide which treatments are most likely to work for you.
For some people, this can include testing for:
These tests don’t change your diagnosis, but they help your team choose the most effective treatment for your type of stomach cancer.
Once stomach cancer is found, your doctors need to work out how far the cancer has spread. This is called staging.
Staging helps your medical team:
In most cases, the stage of a cancer is based on three factors:
These combined factors are known as the TNM staging system.
Your doctor might also use a number between 1 and 4 to describe the stage of your cancer.
Being told you have stomach cancer is shocking and overwhelming. There is no ‘right’ way to feel – everyone reacts differently. You may feel:
All of these reactions are normal.
A lot can happen quickly after diagnosis, and you might get lots of information. It's okay if you don't remember everything you're told or need information repeated.
When you need to chat, our team can help you make sense of what the next steps look like.
After your diagnosis, your medical team will finish any remaining tests that are needed. They will then talk to you about the treatment plan best suited to your situation.
Treatment should start within four weeks of diagnosis, depending on how urgent it is and what type of treatment is recommended.
Here are some questions that you may want to ask your medical team as you come to terms with your diagnosis and think about your treatment options.
Learn more about what happens next through your My Care KIT.
Speak with a specialist cancer nurse, dietitian or counsellor, whether that's understanding a diagnosis, managing day-to-day, tips on managing your diet or just needing someone who understands. Free support for anyone impacted by upper GI cancers, Monday to Friday, 9am to 5pm.
