Diagnosis of stomach cancer
Diagnosing stomach cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and do a physical exam. Based on this information, your doctor may refer you to a specialist or order tests to check for stomach cancer or other health problems.
The process of diagnosis may seem long and frustrating. It’s normal to worry, but try to remember that other health conditions can cause similar symptoms as stomach cancer. It’s important for the healthcare team to rule out other reasons for a health problem before making a diagnosis of stomach cancer.
The following tests are commonly used to rule out or diagnose stomach cancer. Many of the same tests used to diagnose cancer are used to find out the stage, which is how far the cancer has progressed. Your doctor may also order other tests to check your general health and to help plan your treatment.
Health history and physical exam
Your health history is a record of your symptoms, risk factors and all the medical events and problems you have had in the past. In taking a health history, your doctor will ask questions about your history of:
- symptoms that suggest stomach cancer
- H. pylori (Helicobacter pylori) infection
- stomach surgery
- stomach problems such as stomach polyps, chronic inflammation of the stomach (gastritis) and pernicious anemia
Your doctor may also ask about a family history of:
- stomach cancer
- risk factors for stomach cancer
- other cancers
- genetic conditions
A physical exam allows your doctor to look for any signs of stomach cancer. During a physical exam, your doctor may:
- feel the abdomen for enlarged organs, lumps or fluid
- check the lymph nodes in the armpits and above the collar bones
- do a digital rectal exam to check for a lump in the pelvis
Find out more about physical exam.
Complete blood count (CBC)
A CBC measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to check for anemia from long-term (chronic) bleeding into the stomach.
Find out more about complete blood count (CBC).
Blood chemistry tests
Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are functioning and can help find abnormalities. Blood chemistry tests used to diagnose and stage stomach cancer include:
Blood urea nitrogen (BUN) and creatinine may be measured to check kidney function. Increased levels could indicate that cancer has spread to the ureters or kidneys.
Lactate acid dehydrogenase, alkaline phosphatase, transaminase and bilirubin may be measured to check liver function. Increased levels could indicate that cancer has spread to the liver.
Find out more about blood chemistry tests.
Upper gastrointestinal (GI) endoscopy
An upper gastrointestinal endoscopy is an examination of the upper GI tract, including the esophagus, stomach and upper part of the small intestine (duodenum). It allows the doctor to look inside these organs using a flexible tube with a light and lens on the end (an endoscope). This procedure is sometimes called an esophagogastroduodenoscopy (EGD) because it examines all these organs. It may also be called a gastroscopy when only the stomach is examined. You will likely be given medicine to make you sleepy before the procedure starts.
This is the most common test used to diagnose stomach cancer. An upper GI endoscopy is done to:
- examine the stomach for bleeding, ulcers, polyps, tumours and inflammation (gastritis)
- take samples of tissue to be tested in the lab (biopsy)
An ultrasound may be done with an endoscope (endoscopic ultrasound, or EUS) to see how far the tumour has grown into the wall of the stomach and nearby tissues. An EUS can also show if cancer has spread to nearby lymph nodes.
Endoscopic ultrasound (EUS) uses an endoscope with an ultrasound probe at the end. Ultrasound uses high-frequency sound waves to make images of structures in the body. It can provide detailed information about the location, size and depth of the tumour (how far it has spread into the wall of the stomach) and if cancer has spread to lymph nodes or surrounding tissues. EUS is often done at the same time as an upper GI endoscopy.
The endoscopic ultrasound can also be used to guide a needle for a biopsy (EUS-guided needle biopsy) to check for cancer in the wall of the stomach, outside the stomach or in surrounding lymph nodes.
During a biopsy, tissues or cells are removed from the body so they can be tested in the lab. The report from the lab will confirm whether or not cancer cells are present in the sample and what type of cancer cells (such as adenocarcinoma) are present.
Endoscopic biopsy – Tissue is removed using a special tool on an endoscope during an upper GI endoscopy.
EUS-guided needle biopsy – Tissue is removed by a needle that is guided with an endoscopic ultrasound. An EUS-guided needle biopsy can check for cancer deep within the stomach wall, outside the stomach or in surrounding lymph nodes.
Laparoscopic biopsy – A laparoscopic biopsy is usually done after a diagnosis of stomach cancer. It is used during a laparoscopy to look for cancer that may have spread outside of the stomach such as to the peritoneum or lymph nodes. A laparoscopic biopsy removes tissue using a special tool on a thin, flexible lighted tube called a laparoscope.
Find out more about biopsy.
Upper gastrointestinal (GI) series
An upper gastrointestinal series uses x-rays to look for tumours in the esophagus, stomach and first part of the small intestine (duodenum). This test is not used often because it has been replaced by the upper gastrointestinal endoscopy.
Find out more about an upper gastrointestinal (GI) series.
Tumour marker tests
Tumour markers are substances in the blood that may mean stomach cancer is present. Tumour marker tests are generally used to check your response to cancer treatment. They can also be used to diagnose stomach cancer.
The following tumour markers may be measured for stomach cancer:
HER2 (human epidermal growth factor receptor 2) is a gene that can change (mutate). If it changes, it may help a tumour grow (oncogene). HER2 status testing is done to find out the amount of HER2 made by a tumour. Stomach tumours that contain HER2 are called HER2-positive. This information will help doctors plan your treatment.
Find about more about tumour marker tests.
A computed tomography (CT) scan uses special x-ray equipment to make 3-D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures. It is the most common test used to stage stomach cancer. A CT scan is used to:
- see if the cancer has spread to other tissues and organs, such as the lymph nodes or liver
- see if cancer has spread to the ovary in women
- look for a thickening of the stomach wall
- guide a biopsy needle into an area of the body that the cancer may have spread to
A dye (contrast medium) may be given by mouth, injected into a vein (given intravenously) or both before the CT scan. The dye can help the doctor to see structures of the body better. When you take the dye as a drink (by mouth, or orally) it will coat the esophagus, stomach and small intestine. This will help the doctor to examine the lining of the upper GI tract for any abnormal areas. Tell your doctor or the radiology staff if you have had an allergic reaction to dye in the past.
A CT scan is more effective in staging advanced stomach cancer than in finding stomach tumours at an early stage.
Find out more about CT scan.
An x-ray uses small doses of radiation to make an image of the body’s structures on film. It is used to look for cancer that has spread to the lungs. You likely won’t have a chest x-ray if you had a CT scan of the chest.
Find out more about x-ray.
A laparoscopy is surgery that uses a laparoscope (a type of endoscope) to examine or remove internal organs through several small incisions (surgical cuts) in the skin. The laparoscope has a camera on the end that sends live video to a TV screen. It may be used to stage stomach cancer and to help doctors plan your treatment. A laparoscopy is used to:
- check the outside of the stomach (serosa) and nearby lymph nodes for cancer
- look for cancer in other parts of the abdomen, such as the peritoneum or liver, that a CT scan or an ultrasound may have missed
- take a biopsy (laparoscopic biopsy)
- remove fluid (peritoneal washings) from the abdomen to look for cancer cells
A laparoscopy may be used with an ultrasound to help find hidden areas that contain cancer.
A positron emission tomography (PET) scan uses radioactive materials called radiopharmaceuticals to look for changes in the metabolic activity of body tissues. A computer analyzes the radioactive patterns and makes 3-D colour images of the area being scanned.
A PET scan is used to look for cancer that has spread outside of the stomach. Sometimes a PET scan may be done at the same time as a CT scan (PET/CT scan).
Find out more about PET scan.
Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3-D pictures.
An MRI is used to look for cancer in the stomach or cancer that has spread outside of the stomach.
Find out more about MRI.
Ultrasound uses high-frequency sound waves to make images of structures in the body. It is used:
- with an endoscopy to look at how far cancer has spread into the wall of the stomach and if cancer has spread to lymph nodes or surrounding tissues
- to guide a needle for a biopsy
- to look for cancer that has spread to the liver (liver ultrasound)
Find out more about ultrasound.
Questions to ask your healthcare team
A type of anemia (a reduction in red blood cells) caused by the body’s inability to absorb vitamin B12.
An imaging technique that uses high-frequency sound waves to produce images of structures and organs inside the body.
The image produced is called a sonogram.
Also called ultrasonography or sonography.
A thin, tube-like instrument with a light and lens used to examine or treat organs or structures in the body.
An endoscope can be flexible or rigid. It may have a tool to remove tissue for examination. Specialized endoscopes may have tools designed to examine or treat specific organs or structures in the body.
Specialized endoscopes are named for the organ or structure they are used to examine or treat.
A procedure that uses an endoscope (a thin, tube-like instrument with a light and lens) to examine or treat organs inside the abdomen and pelvis.
Cells or tissue may be removed for examination under a microscope. Doctors may also use laparoscopy to perform different surgical procedures in the abdomen and pelvis.
The type of endoscope used for this procedure is called a laparoscope.
The membrane that lines the walls of the abdomen and pelvis (parietal peritoneum), and covers and supports most of the abdominal organs (visceral peritoneum).
A gene involved in the control of cell growth and division that may cause the growth of cancer cells.
An oncogene may be a normal gene that has mutated (proto-oncogene), a normal gene with abnormal gene expression or a gene that comes from a cancer-causing virus.
A substance used in some diagnostic procedures to help parts of the body show up better on x-rays or other imaging tests.
In most cases, contrast medium is injected into or around the structure to be examined.
Also called contrast dye or contrast agent.