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 is an abnormal growth of cells that begins in the stomach. The stomach is a muscular sac located in the upper middle of your abdomen, just below your ribs. Your stomach receives and holds the food you eat and then helps to break down and digest it.

Stomach cancer, also known as gastric cancer, can affect any part of the stomach. In most of the world, stomach cancers form in the main part of the stomach (stomach body).

But in the United States, stomach cancer is more likely to affect the area where the long tube (esophagus) that carries food you swallow meets the stomach. This area is called the gastroesophageal junction.

Where the cancer occurs in the stomach is one factor doctors consider when determining your treatment options. Treatment usually includes surgery to remove the stomach cancer. Other treatments may be recommended before and after surgery.


Signs and symptoms of stomach cancer may include:

  • Difficulty swallowing
  • Feeling bloated after eating
  • Feeling full after eating small amounts of food
  • Heartburn
  • Indigestion
  • Nausea
  • Stomach pain
  • Unintentional weight loss
  • Vomiting

When to see a doctor

If you have signs and symptoms that worry you, make an appointment with your doctor. Your doctor will likely investigate more-common causes of these signs and symptoms first.

Get Mayo Clinic cancer expertise delivered to your inbox.

Subscribe for free and receive an in-depth guide to coping with cancer, plus helpful information on how to get a second opinion. You can unsubscribe at any time.

I would like to learn more about

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.


It's not clear what causes stomach cancer, though research has identified many factors that can increase the risk.

Doctors know that stomach cancer begins when a cell in the stomach develops changes in its DNA. A cell's DNA contains the instructions that tell the cell what to do. The changes tell the cell to grow quickly and to continue living when healthy cells would die. The accumulating cells form a tumor that can invade and destroy healthy tissue. With time, cells can break off and spread (metastasize) to other areas of the body.

Risk factors

Factors that increase the risk of stomach cancer include:

  • Gastroesophageal reflux disease
  • Obesity
  • A diet high in salty and smoked foods
  • A diet low in fruits and vegetables
  • Family history of stomach cancer
  • Infection with Helicobacter pylori
  • Long-term stomach inflammation (gastritis)
  • Smoking
  • Stomach polyps


To reduce the risk of stomach cancer, you can:

  • Maintain a healthy weight. If you're overweight or obese, talk to your doctor about strategies to help you lose weight. Aim for a slow and steady weight loss of 1 or 2 pounds a week.
  • Choose a diet full of fruits and vegetables. Try to incorporate more fruits and vegetables into your diet each day. Choose a wide 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, as well as many other types of cancer. Quitting smoking can be very difficult, so ask your doctor for help.
  • Ask your doctor about your risk of stomach cancer. Talk with your doctor if you have an increased risk of stomach cancer. People with a strong family history of stomach cancer might consider tests, such as endoscopy, to look for signs of stomach cancer.

Stomach cancer care at Mayo Clinic

April 27, 2021

Living with stomach cancer?

Connect with others like you for support and answers to your questions in the Proton Beam Therapy support group on Mayo Clinic Connect, a patient community.

Proton Beam Therapy Discussions

What's the difference between proton vs traditional radiation?

13 Replies Sat, Feb 12, 2022

Starting Proton Treatments for Prostate Cancer: Any experiences?

12 Replies Sat, Feb 05, 2022

What's your experience: proton SBRT non small cell lung cancer?

5 Replies Thu, Sep 23, 2021

See more discussions
  1. AskMayoExpert. Gastric cancer (adult). Mayo Clinic; 2020.
  2. Gastric cancer. National Comprehensive Cancer Network. https://www.nccn.org/professionals/physician_gls/default.aspx. Accessed July 24, 2020.
  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 24, 2020.
  4. Gastric cancer treatment (PDQ). National Cancer Institute. https://www.cancer.gov/types/stomach/patient/stomach-treatment-pdq. Accessed July 27, 2020.
  5. Gastric (stomach) cancer prevention (PDQ). National Cancer Institute. https://www.cancer.gov/types/stomach/patient/stomach-prevention-pdq. Accessed July 27, 2020.
  6. Palliative care. National Comprehensive Cancer Network. https://www.nccn.org/professionals/physician_gls/default.aspx. Accessed July 24, 2020.
  7. Warner KJ. Allscripts EPSi. Mayo Clinic. Feb. 12, 2020.