Diagnostic tools such as upper endoscopy may help doctors detect stomach cancer early. Doctors may screen for stomach cancer in people at an increased risk of developing the disease.

Some people may experience early symptoms of stomach cancer that lead to a diagnosis.

This article looks at the early detection of stomach cancer, warning signs of stomach cancer, screening, and more.

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In the United States, there is no routine screening program for stomach cancer in those at average risk. This means people may only become aware of stomach cancer through early symptoms.

People who have a high risk of stomach cancer may undergo regular screening, which can help doctors detect precancerous or cancerous changes.

People at higher risk of stomach cancer include those with:

Screening may involve an upper endoscopy, which is a procedure where a doctor inserts a thin tube with a camera on one end through the throat to examine the stomach area.

People with a family history of hereditary diffuse gastric cancer (HDGC) may require stomach removal because they have a very high risk of stomach cancer.

Doctors will then use a range of tests to determine the presence and stage of stomach cancer.

In the U.S., doctors typically find stomach cancer when the tumor has grown larger or the cancer is present outside the stomach.

Warning signs of stomach cancer may include:

These symptoms may occur in the early stages of stomach cancer.

Before diagnosing stomach cancer, doctors may first ask people about any symptoms they are experiencing and take a full medical history.

A doctor will also perform a physical exam of the stomach to check for abnormalities.

To diagnose stomach cancer, doctors may use a range of tests and procedures, including:

  • Upper endoscopy: This is the most common test for stomach cancer. A doctor will insert a thin, flexible tube with a light and camera on the end through the throat to examine the esophagus, stomach, and beginning of the small intestine.
  • Biopsy: During an endoscopy, a doctor may take small tissue samples. A doctor will send these samples to a laboratory for examination under a microscope to check for cancer cells.
  • Endoscopic ultrasound: Doctors use a small ultrasound attached to an endoscope to create images of the inside of the stomach. This can help identify abnormalities and check whether the cancer has spread to surrounding lymph nodes or other areas.
  • X-rays: Doctors may use an X-ray to examine the inside of the esophagus, stomach, and first section of the small intestine. Before the test, people may drink a barium solution, which is a substance that allows an X-ray to show any abnormalities.
  • CT scan: A CT scan creates detailed images of the soft tissues and can provide a clear image of the stomach. CT scans can also help doctors determine the stage of cancer if present.
  • PET scans: For a PET scan, doctors first inject a person with a radioactive sugar that will collect in cancer cells. Doctors use a special camera to see any areas of radioactivity in the body, which may indicate cancer cells.
  • MRI scans: MRI scans use powerful magnets to provide detailed images of the soft tissues. MRI scans may not be as useful as other tests to diagnose stomach cancer, but they may be useful for checking if cancer has spread.

If doctors find stomach cancer with other tests, they may carry out minor surgery to confirm that the cancer is only present in the stomach.

A doctor may make a small incision in the abdomen to insert a laparoscope, which is a tube with a camera at one end. Doctors can insert it through the abdominal wall to examine the abdomen and guide the procedure.

A doctor may take a biopsy or use a saline solution to wash the abdomen to create a fluid sample, which a laboratory can then test for cancer cells.

It can be challenging to detect stomach cancer early, but specialists with high levels of experience in using endoscopy may be able to spot the subtle signs of very early stomach cancer.

The earlier people receive a diagnosis and treatment, the greater the chance of successful treatment and a positive outlook.

This section answers some frequently asked questions about stomach cancer and early detection.

Does stage 1 stomach cancer have symptoms?

It is rare for early stage stomach cancer to cause symptoms. If symptoms do occur, early stage stomach cancer may cause:

  • stomach discomfort
  • indigestion
  • heartburn
  • bloating after eating
  • mild nausea
  • loss of appetite

Does stomach cancer show up in a blood test?

Blood tests may not directly indicate stomach cancer, but they can help doctors check for any abnormal signs related to stomach cancer.

Doctors may use blood tests to check for anemia, or low red blood cell count, which may indicate bleeding in the stomach from cancer.

Doctors may also check for blood in the stools, which could indicate stomach bleeding.

After a cancer diagnosis, a doctor may use blood tests to check how well other organs are functioning, such as the liver and kidneys. They may also check blood clotting function.

Currently, researchers are investigating a new type of test called a multi-cancer early detection test (MCED) that may be able to detect multiple types of cancer from a blood sample.

Medical professionals do not yet use them as standard care, and they are typically costly. However, this research is promising for the future of cancer diagnosis.

Stomach cancer may not cause symptoms in the early stages. If people do experience symptoms, they may include stomach discomfort, bloating, and indigestion.

If people experience any symptoms of stomach cancer, they should contact a doctor to determine the underlying cause.

Certain diagnostic tools, such as upper endoscopy, may help doctors spot signs of early stage stomach cancer. Early diagnosis and treatment may lead to better outcomes.