Cancer can start any place in the body. Stomach cancer (also called gastric cancer) starts in the stomach. It starts when cells in the stomach grow out of control and crowd out normal cells. This makes it hard for the body to work the way it should.
Cancer cells can spread to other parts of the body. For example, cancer cells in the stomach can sometimes travel to the liver and grow there. When cancer cells do this, it’s called metastasis. To doctors, the cancer cells in the new place look just like the ones from the stomach.
Cancer is always named based on the place where it starts. So when stomach cancer spreads to the liver (or any other part of the body), it’s still called stomach cancer. It’s not called liver cancer unless it starts from cells in the liver.
Ask your doctor to show you where your cancer is.
There are many types of stomach cancer. Some are very rare. Most stomach cancers are adenocarcinomas. These cancers start from gland cells that line the inside of the stomach. If you are told you have stomach cancer (or gastric cancer), it will almost always be an adenocarcinoma.
Symptoms of stomach cancer can include:
If you have symptoms that might be from stomach cancer, your doctor will ask you questions about them and do a physical exam. You might also be referred to a gastroenterologist (a doctor who treats diseases of the digestive system), who might do more exams and tests.
Here are some of the exams and tests you may need:
Tests to look for bleeding: The doctor might order a blood test to check for a low red blood cell count, which could be caused by the cancer bleeding into the stomach. A test might also be done to look for blood in your stool (feces) that can't be seen by the naked eye, which could also be a sign of bleeding in the stomach.
Upper endoscopy or EGD: This is the test most often done if you might have stomach cancer. For this test, a bendable, thin tube with a tiny light and video camera on the end is put in your mouth and passed down into your throat and stomach. If there are any spots that look like cancer, small pieces of them can be taken out (biopsied) through the tube and checked for cancer cells.
Endoscopic ultrasound (EUS): This test can be done during an upper endoscopy. A small probe is placed on the tip of the thin tube that is passed down the throat into the stomach. It uses sound waves and their echoes to make pictures of the layers of the stomach wall. It can also be used to take out small pieces of abnormal areas that can be checked for cancer.
Upper GI series: This test is a series of x-rays taken after you swallow barium, a thick, chalky liquid that shows up on x-rays. This can show problems in the inner lining of the throat, stomach, and part of the small intestine.
CT or CAT scan: This test uses x-rays to make detailed pictures of your insides. This can show the size of the cancer and if it has spread.
MRI scan: This test uses radio waves and strong magnets to make detailed pictures. It can show more about the size of the cancer and its spread.
PET scan: This test uses a special kind of sugar that can be seen inside your body with a special camera. If there is cancer, this sugar shows up as “hot spots” where the cancer is found. This test can help show if the cancer has spread.
Laparoscopy: If stomach cancer has been found, this exam might be done to see if surgery could be a treatment option. A thin, bendable tube with a small video camera on the end is put into the belly through a small cut. This lets the doctor look for the growth or spread of cancer inside the belly.
Lab tests: Lab tests might be done to check your blood. They can offer details about your health status, or about the cancer itself. They can be used to find problems and guide treatment.
In a biopsy, the doctor takes out small pieces of abnormal areas that might be cancer. These are checked for cancer cells. A biopsy is the only way to tell for sure if you have cancer. For stomach cancer, a biopsy is most often done during an upper endoscopy.
If you have stomach cancer, the doctor will want to find out how far it has spread to help decide what type of treatment is best for you. This is called the stage of the cancer. The tests above are used to help stage the cancer.
The stage describes the growth or spread of the cancer in the stomach or into nearby areas. It also tells if the cancer has spread to other parts of the body that are farther away.
Your cancer can be stage 1, 2, 3, or 4. The lower the number, the less the cancer has spread. A higher number means the cancer has spread more. Be sure to ask the doctor about the cancer stage and what it means for you.
There are many ways to treat stomach cancer, but the main types of treatment are:
Often more than one treatment is used.
The treatment plan that’s best for you will depend on:
Surgery is often part of the treatment for stomach cancer if it can be done. There are different kinds of surgery. The type that’s best for you depends on how big the cancer is and where it is in the stomach. Surgery might be done for different reasons. If the cancer is small enough, it might be done to try to remove all of it. If the cancer can’t be removed, surgery might be done to help prevent or relieve symptoms. Ask your doctor what kind of surgery you will have and what to expect.
Any type of surgery can have risks and side effects, such as bleeding or infections. If part or all of your stomach is removed, it can affect the way you eat. Be sure to ask the doctor what you can expect. If you have problems, let your doctors know. Doctors who treat people with stomach cancer should be able to help you with any problems that come up.
Chemo is the short word for chemotherapy – the use of drugs to fight cancer. The drugs may be given into a vein or taken as pills. These drugs go into the blood and spread through the body. Chemo is given in cycles or rounds. Each round of treatment is followed by a break. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months. Chemo can be given before or after surgery. It can also be given together with radiation. Ask your doctor what to expect.
Chemo can make you feel very tired or sick to your stomach. You might have diarrhea or mouth sores, and your hair might fall out. But these problems often go away after treatment ends.
There are ways to treat most chemo side effects. If you have side effects, be sure to talk to your cancer care team so they can help.
Radiation uses high-energy rays (like x-rays) to kill cancer cells. It is aimed at the cancer from a machine outside the body. Radiation might be used along with chemo (before or after surgery), or it might be used by itself.
Side effects depend on where the radiation is aimed. The most common side effects of radiation are:
Most side effects get better after treatment ends. Some might last longer. Talk to your cancer care team about what you can expect.
Targeted drugs are newer treatments that may be used for some types of stomach cancer. These drugs affect mainly cancer cells and not normal cells in the body. They may work even if other treatments don’t. These drugs have different side effects from chemo, so talk to your cancer care team about what to expect.
Immunotherapy is treatment that boosts the body's immune system to help fight the cancer. The type of immunotherapy used to treat stomach cancer is given into a vein (IV).
The side effects of these drugs tend to be mild, but rarely they can cause the immune system to attack normal cells in the body, which can lead to serious problems. Talk to your cancer care team so you know what to expect and when you might need to contact them.
Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better.
Clinical trials are one way to get the newest cancer treatments. They are the best way for doctors to find better ways to treat cancer. Still, they’re not right for everyone. And it’s up to you whether to take part in a clinical trial.
If you would like to learn more about clinical trials that might be right for you, start by asking your doctor if your clinic or hospital conducts clinical trials. See Clinical Trials to learn more.
You might hear about other ways to treat the cancer or to treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, special diets, and other things.
Some of these are known to help, but many have not been tested. Some have been shown not to help. A few have even been found to be harmful. Talk to your doctor about anything you’re thinking about using, whether it’s a vitamin, a diet, or anything else.
If you've completed treatment, you’ll be glad when it's over. But it can be hard not to worry about cancer coming back. Even when cancer never comes back, people still worry about it.
For years after treatment ends, it will still be important to see your cancer doctors. Follow-up is needed to watch for treatment side effects and to check for cancer that has come back or spread. Be sure to go to all of your follow-up visits. During these visits, they will ask about symptoms and examine you. If you're having symptoms, you might need to get lab tests, imaging tests, or an endoscopy.
At first, follow-up visits may be every few months. Over time, the visits might be needed less often. Your cancer care team can tell you more about these visits, when you might need to contact them if problems come up, and what else to expect after treatment.
Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.
Adenocarcinoma (AD-uh-no-kar-suh-NO-muh): Cancer that starts in gland cells. Most stomach cancers are adenocarcinomas.
Biopsy (BY-op-see): Taking out a small piece of an abnormal area to see if there are cancer cells in it.
Endoscopy (en-DOS-kuh-pee): The use of a thin, flexible tube with a lens or tiny video camera on the end to look inside the body.
Gastric (GAS-trick): Of or referring to the stomach.
Gastroenterologist (GAS-tro-en-tuh-ROL-uh-jist): A doctor who treats diseases of the digestive system.
Metastasis (muh-TAS-tuh-sis): The spread of cancer from where it started to other parts of the body.
Last Revised: January 22, 2021