What is stomach cancer? A Mayo Clinic expert explains

Learn more about stomach cancer from oncologist Mohamad (Bassam) Sonbol, M.D.

I'm Dr. Bassam Sonbol, an oncologist at Mayo Clinic. In this video we'll cover the basics of stomach cancer: What is it? Who gets it? The symptoms, diagnosis, and treatment. Whether you're looking for answers for yourself or someone you love, we're here to give you the best information available. Stomach cancer, also called gastric cancer, can happen in any part of the stomach. However, in the U.S., most stomach cancers occur in the gastroesophageal junction, which is where the esophagus - the tube that carries chewed up food - meets the stomach. There are several different types of stomach cancers, but most are curable if detected at an early stage. What once was the leading cause of cancer death is now well down on the list thanks to the advancement in technology and scientific research. In fact, new cases of stomach cancers have dropped by about 1.5% every year for the last 10 years.

Stomach cancer more commonly affects older people. The average age of those diagnosed with stomach cancer is 68. Around 60% of cases occur in patients older than 65, and there is a slightly higher lifetime risk of stomach cancer in men. However, it can affect anyone. Stomach cancer tends to develop slowly over time, usually over many years. What happens is small changes occur in the DNA of the stomach cells, telling them to over multiply and then they accumulate, forming abnormal growth called tumors. There are several known risk factors that could increase your risk of developing stomach cancer, for instance, smoking doubles your risk of stomach cancer, family history of stomach cancer, infection with H. pylori, long-term stomach inflammation, gastroesophageal reflux disease, or stomach polyps. Eating a diet high in salty and smoked foods or low in fruits and vegetables can be also a risk. And there is some correlation between higher weight and risk, as well.

Stomach cancer can present itself in several different ways, such as difficulty swallowing, feeling bloated after eating, feeling full after only eating a small amount of food, heartburn, indigestion, nausea, stomach pain, unintentional weight loss, and vomiting. If you have any signs and symptoms that worry you, make an appointment with your doctor. Your doctor may investigate the more common causes of these symptoms first or refer you to a specialist, like a gastroenterologist or an oncologist, like me.

To determine if you have stomach cancer, your doctor may start with an upper endoscopy, where a tiny camera is passed through the throat and into the stomach. If your doctor finds something suspicious, they remove some tissue for a biopsy, where the cells gets sent to a lab for further analysis. Your doctor may also run some imaging tests, like CT scan or a special x-ray called a barium swallow. Identifying the extent of the cancer helps your doctor determine the best treatment. To determine the stage, they will run more tests, like blood tests, endoscopic ultrasound, CT scan, or a PET scan. In some cases, your doctor may recommend laparoscopic surgery, where the doctor inserts a special camera directly into the abdomen.

Creating a treatment plan for stomach cancer is a collaborative effort between doctors from different specialties. Our goal is to make the best treatment plan for your overall health and personal well-being. There are five main treatment options for stomach cancer: Surgery to remove all of the cancerous tissue and probably some of the healthy tissue around it. Chemotherapy, which uses drugs that journey throughout the body, destroying any cancer cells in its path. Radiation therapy, which uses high-powered beams of energy to target cancer cells. Targeted drug therapy, focusing on blocking specific weaknesses present within cancer cells. And immunotherapy, a drug treatment that helps your immune system recognize which cells are dangerous and attack them.

Finding out you have cancer can be really overwhelming and difficult. It can help to find spaces where other people understand what you're going through. Try connecting with cancer survivors online or in your community. Learning about your condition can help you make confident decisions about your care. If you'd like to learn more about stomach cancer, watch our other related videos or visit mayoclinic.org. We wish you well.

Stomach cancer, which is also called gastric cancer, is a growth of cells that starts in the stomach. The stomach is in the upper middle part of the belly, just below the ribs. The stomach helps to break down and digest food.

Stomach cancer can happen in any part of the stomach. In most of the world, stomach cancers happen in the main part of the stomach. This part is called the stomach body.

In the United States, stomach cancer is more likely to start by the gastroesophageal junction. This is the part where the long tube that carries food you swallow meets the stomach. The tube that carries food to the stomach is called the esophagus.

Where the cancer starts in the stomach is one factor health care providers think about when making a treatment plan. Other factors might include the cancer's stage and the type of cells involved. Treatment often includes surgery to remove the stomach cancer. Other treatments may be used before and after surgery.

Stomach cancer treatment is most likely to be successful if the cancer is only in the stomach. The prognosis for people with small stomach cancers is quite good. Many can expect to be cured. Most stomach cancers are found when the disease is advanced and a cure is less likely. Stomach cancer that grows through the stomach wall or spreads to other parts of the body is harder to cure.


Signs and symptoms of stomach cancer may include:

  • Trouble swallowing
  • Belly pain
  • Feeling bloated after eating
  • Feeling full after eating small amounts of food
  • Not feeling hungry when you would expect to be hungry
  • Heartburn
  • Indigestion
  • Nausea
  • Vomiting
  • Losing weight without trying
  • Feeling very tired
  • Stools that look black

Stomach cancer doesn't always cause symptoms in its early stages. When they happen, symptoms might include indigestion and pain in the upper part of the belly. Symptoms might not happen until the cancer is advanced. Later stages of stomach cancer might cause symptoms such as feeling very tired, losing weight without trying, vomiting blood and having black stools.

Stomach cancer that spreads to other parts of the body is called metastatic stomach cancer. It causes symptoms specific to where it spreads. For example, when cancer spreads to the lymph nodes it might cause lumps you can feel through the skin. Cancer that spreads to the liver might cause yellowing of the skin and whites of the eyes. If cancer spreads within the belly, it might cause fluid to fill the belly. The belly might look swollen.

When to see a doctor

If you have signs and symptoms that worry you, make an appointment with your health care provider. Many conditions can cause symptoms that are like the ones caused by stomach cancer. Your provider might test for those other causes first before testing for stomach cancer.

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It's not clear what causes stomach cancer. Experts believe most stomach cancers start when something hurts the inside lining of the stomach. Examples include having an infection in the stomach, having long-standing acid reflux and eating a lot of salty foods. Not everyone with these risk factors gets stomach cancer, though. So more research is needed to find out exactly what causes it.

Stomach cancer begins when something hurts cells in the inner lining of the stomach. It causes the cells to develop changes in their DNA. A cell's DNA holds the instructions that tell a cell what to do. The changes tell the cells to multiply quickly. The cells can go on living when healthy cells would die as part of their natural lifecycle. This causes a lot of extra cells in the stomach. The cells can form a mass called a tumor.

Cancer cells in the stomach can invade and destroy healthy body tissue. They might start to grow deeper into the wall of the stomach. In time, cancer cells can break away and spread to other parts of the body. When cancer cells spread to another part of the body it's called metastasis.

Types of stomach cancer

The type of stomach cancer you have is based on the type of cell where your cancer began. Examples of stomach cancer types include:

  • Adenocarcinoma. Adenocarcinoma stomach cancer starts in cells that produce mucus. This is the most common type of stomach cancer. Nearly all cancers that start in the stomach are adenocarcinoma stomach cancers.
  • Gastrointestinal stromal tumors (GIST). GIST starts in special nerve cells that are found in the wall of the stomach and other digestive organs. GIST is a type of soft tissue sarcoma.
  • Carcinoid tumors. Carcinoid tumors are cancers that start in the neuroendocrine cells. Neuroendocrine cells are found in many places in the body. They do some nerve cell functions and some of the work of cells that make hormones. Carcinoid tumors are a type of neuroendocrine tumor.
  • Lymphoma. Lymphoma is a cancer that starts in immune system cells. The body's immune system fights germs. Lymphoma can sometimes start in the stomach if the body sends immune system cells to the stomach. This might happen if the body is trying to fight off an infection. Most lymphomas that start in the stomach are a type of non-Hodgkin's lymphoma.

Risk factors

Factors that increase the risk of stomach cancer include:

  • Ongoing problems with stomach acid backing up into the esophagus, which is called gastroesophageal reflux disease
  • A diet high in salty and smoked foods
  • A diet low in fruits and vegetables
  • Infection in the stomach caused by a germ called Helicobacter pylori
  • Swelling and irritation of the inside of the stomach, which is called gastritis
  • Smoking
  • Growths of noncancerous cells in the stomach, called polyps
  • Family history of stomach cancer
  • Family history of genetic syndromes that increase the risk of stomach cancer and other cancers, such as hereditary diffuse gastric cancer, Lynch syndrome, juvenile polyposis syndrome, Peutz-Jeghers syndrome and familial adenomatous polyposis


To lower the risk of stomach cancer, you can:

  • Eat plenty of fruits and vegetables. Try to include fruits and vegetables in your diet each day. Choose a variety of colorful fruits and vegetables.
  • Reduce the amount of salty and smoked foods you eat. Protect your stomach by limiting these foods.
  • Stop smoking. If you smoke, quit. If you don't smoke, don't start. Smoking increases your risk of stomach cancer and many other types of cancer. Quitting smoking can be very hard, so ask your health care provider for help.
  • Tell your health care provider if stomach cancer runs in your family. People with a strong family history of stomach cancer might have stomach cancer screening. Screening tests can detect stomach cancer before it causes symptoms.

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  1. AskMayoExpert. Gastric cancer (adult). Mayo Clinic; 2020.
  2. Gastric cancer. National Comprehensive Cancer Network. https://www.nccn.org/guidelines/guidelines-detail?category=1&id=1434. Accessed July 22, 2022.
  3. Niederhuber JE, et al., eds. Cancer of the stomach. In: Abeloff's Clinical Oncology. 6th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed July 22, 2022.
  4. Gastric cancer treatment (PDQ). National Cancer Institute. https://www.cancer.gov/types/stomach/patient/stomach-treatment-pdq. Accessed July 22, 2022.
  5. Gastric (stomach) cancer prevention (PDQ). National Cancer Institute. https://www.cancer.gov/types/stomach/patient/stomach-prevention-pdq. Accessed July 22, 2022.
  6. Palliative care. National Comprehensive Cancer Network. https://www.nccn.org/guidelines/guidelines-detail?category=3&id=1454. Accessed July 22, 2022.
  7. Odze RD, et al., eds. Epithelial neoplasms of the stomach. In: Surgical Pathology of the GI Tract, Liver, Biliary Tract and Pancreas. 4th ed. Elsevier; 2023. https://www.clinicalkey.com. Accessed Aug. 5, 2022.
  8. Mansfield PF. Clinical features, diagnosis and staging of gastric cancer. https://www.uptodate.com/contents/search. Accessed Aug. 5, 2022.
  9. Andreas A, et al., eds. The stomach. In: Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed Aug. 5, 2022.
  10. Xia JY, et al. Advances in screening and detection of gastric cancer. Journal of Surgical Oncology. 2022; doi:10.1002/jso.26844.
  11. Best hospitals for gastroenterology and GI surgery. U.S. News & World Report. https://health.usnews.com/best-hospitals/rankings/gastroenterology-and-gi-surgery. Accessed Aug. 2, 2022.
  12. Best hospitals for cancer. U.S. News & World Report. https://health.usnews.com/best-hospitals/rankings/cancer. Accessed Sept. 9, 2022.
  13. Warner KJ. Allscripts EPSi. Mayo Clinic. Feb. 12, 2020.