What Is Gastric Cancer?

Gastric cancer (stomach cancer) is when abnormal cells grow in the stomach. It can occur anywhere in the stomach. The incidence of this type of cancer is decreasing in the United States as some of the risk factors for the disease are declining. However, stomach cancer is a leading cause of death in other parts of the world.

Stomach cancer is connected to various diseases and conditions as well as certain environmental triggers and lifestyle factors. Treatment may involve surgery to remove tumors and/or either part or all of the stomach as well as drug therapy or radiation to kill cancer cells.

Types of Gastric Cancer

There are several different types of stomach cancer. The most common type is adenocarcinoma.

Adenocarcinoma

More than 90% of stomach cancers are adenocarcinoma. The inner lining of the stomach is called the mucosa. Adenocarcinoma of the stomach starts in the cells in the mucosa. This type of cancer has subtypes which includes distal (noncardia), proximal, and diffuse stomach cancer. Distal cancer may be related to a chronic infection with H pylori. Proximal stomach cancer is more common in the United States and is found at the top of the stomach and sometimes where the stomach meets the esophagus. Diffuse stomach cancer is more aggressive and decentralized so therefore more challenging to diagnose and treat. It's often diagnosed in younger people with a family history of stomach cancers.

Gastrointestinal stromal tumor (GIST)

This type of stomach cancer begins in the connective tissue or the muscles of the stomach. GIST is a rare type of stomach cancer. It can be either noncancerous (benign) or cancerous (malignant).

Gastric lymphoma

This type of stomach cancer is less common. Lymphomas are cancers of the immune system. The walls of the stomach may contains cells that are part of the immune system. Lymphoma stomach cancer begins in these cells.

Carcinoid tumor

There are cells in the stomach which produce certain hormones. A carcinoid tumor begins in these cells. Most of the time, this type of cancer does not spread outside the stomach.

Gastric Cancer Symptoms

The symptoms of stomach cancer can be similar to many other conditions. What's important to note is not only that these signs and symptoms are happening but also that they are occurring frequently.

Having symptoms on occasion, such as after eating a heavy meal, doesn't mean that stomach cancer is present. Talking to a doctor about any problems with the stomach will help in finding out if there is a reason to get checked out with any tests.

The signs and symptoms of stomach cancer can include:

• Bloating after eating
• Heartburn
• Lack of appetite
• Nausea
• Upset stomach (indigestion or dyspepsia)

When gastric cancer becomes more advanced, it can lead to other signs and symptoms that are more concerning. These symptoms might occur because the tumors are growing:

• Abdominal pain
• Bloody stool or dark, tarry stool
• Diarrhea or constipation
• Difficulty in swallowing
• Fatigue
• Stomach distention (bloating)
• Unintended weight loss
• Vomiting
• Weakness
• Yellow eyes or skin (jaundice)

Causes

It's not clear what causes stomach cancer. It is known that some people may have risk factors for developing this type of cancer.

There are a few conditions that make a person more likely to develop stomach cancer. There are also lifestyle and environmental risk factors that may increase a person's chances of having gastric cancer. However, not everyone who develops stomach cancer will have these risk factors.

Some of the conditions that are associated with stomach cancer include:

• Helicobacter pylori bacterial infection: A stomach infection with H. pylori is common, affecting an estimated half of the world's population. It causes stomach ulcers and is treated with antibiotics. Having an H. pylori infection doesn't always mean that a person will later go on to have stomach cancer. However, it is still considered a fairly significant risk factor.
• Common variable immune deficiency (CVID): In this condition, the body doesn't make enough of the proteins that fight off infection. People with CVID often have repeated infections. It is also associated with an increased risk of cancers, including gastric cancer.
• Family history of stomach cancer: People who have a first-degree relative (which is a parent, sibling, or child) with stomach cancer have a greater risk of developing the disease.
• Epstein-Barr virus infection: This is a common virus and most people become infected as a child or a teenager. Epstein-Barr virus causes mononucleosis (mono). This virus has been found in some stomach cancer cells but it's still not understood exactly how it is connected to the disease.
• Inherited cancers: There are several types of conditions that are passed down through a person's genes that can increase the risk of developing stomach cancer. This includes hereditary diffuse gastric cancer, Lynch syndrome, familial adenomatous polyposis, Li-Fraumeni syndrome, and Peutz-Jeghers syndrome. Having certain mutations in the BRCA 1 and BRCA 2 genes, typically associated with breast cancer can increase the risk of stomach cancer in rare cases.
  
• Ménétrier’s disease (hypertrophic gastropathy): This rare disease is associated with an increased risk of stomach cancer. It's unclear how this condition develops but it is thought that there may be a genetic cause and an environmental trigger.
• Mucosa-associated lymphoid tissue (MALT) lymphoma: This type of lymphoma is in the stomach. People who have MALT are at an increased risk of developing gastric adenocarcinoma. It's thought that this could also be related to an infection with H. pylori, because the infection causes MALT.
• Pernicious anemia: A type of anemia that is caused by a lack of intrinsic factor may be associated with stomach cancer. Intrinsic factor is made by the cells in the stomach and without enough, the body may not absorb enough vitamin B12. Vitamin B12 is needed to make new red blood cells, among other functions. Pernicious anemia is the result.

The lifestyle and environmental factors associated with stomach cancer include:

• Asbestos exposure
• Blood type A
• Diets high in smoked or pickled foods or salted meat or fish
• Environmental exposures through work in the coal, metal, timber, or rubber industries
• Being overweight or obese
• Previous stomach ulcer surgery
• Smoking cigarettes

Diagnosis

Several different types of tests may be used to diagnose stomach cancer. When stomach cancer is diagnosed, it may also be necessary to do some tests or procedures to determine how far advanced the cancer is (called staging).

Some of the tests that might be used to diagnose gastric cancer and/or determine what stage it is include:

• Blood tests: Various blood tests may be used, such as a complete blood cell (CBC) count. A CBC count may be used to look for anemia. Tests that can look for problems with the liver and the kidneys may also be done.
• Chest X-ray: An X-ray of the chest won't be able to diagnose stomach cancer, but it may be used to determine if there is cancer that has spread to the lungs.
• Computerized tomography (CT) scan: A CT scan is a type of X-ray. This test takes a series of images that can give a cross-sectional view of the organs inside the body. Sometimes a substance called contrast is injected into a vein. The contrast allows for parts of the body to be better seen on the images.
• Endoscopic ultrasound: This test uses an ultrasound probe attached to an endoscope. The endoscope is passed through the mouth and into the stomach. The ultrasound probe on the end is used to create images of the digestive organs. In this test, it might be able for a physician to see if the cancer has passed deeper into the walls of the stomach.
• Positron emission tomography (PET) scan: This imaging test uses a radioactive glucose solution that collects in cancer cells and shows up on the images taken. The images don't show the body structures as well as some other tests can. It may not be quite as useful in stomach cancer as it is for other types of cancer. However, it can help determine if there is cancer that has spread to other organs and structures.
• Surgery: Exploratory or laparoscopic surgery might be used after stomach cancer is diagnosed. Through this type of surgery, a physician can ensure all areas of cancer have been found. A small incision is made in the abdomen and a small instrument with a camera on the end is passed through it in order to see inside the abdomen. It is done under general anesthesia (the patient is fully asleep).
• Upper endoscopy (also called esophagogastroduodenoscopy or EGD): A thin, flexible tube with a light and a camera on the end is inserted into the mouth. A physician guides it down the esophagus into the stomach. The lining of the esophagus and stomach can be seen. Biopsies (small pieces of tissue) can be taken during endoscopy to analyze them for the presence of inflammation or cancer.
• Upper gastrointestinal series: This test is also sometimes called a barium swallow. Patients drink a solution of barium contrast. After that, X-rays of the upper digestive tract (which includes the stomach) are taken while the barium passes through.

Treatment

The treatment for stomach cancer will depend on a variety of factors. A person's overall health and any other conditions are considered when determining the best treatment. The stage of the cancer, its location, and if it is considered to be fast-growing will all affect treatment decisions.

Surgery

One of the main treatments for stomach cancer is surgery. The type of surgery that's needed will be different based on how far the cancer extends into the stomach or beyond it. Surgery will be done to remove the cancer and any other surrounding tissues as needed.

Tumor Removal

This surgery might be used if the cancer is in the early stages. Tumors that are confined to the lining of the stomach might be removed during an endoscopy procedure. An instrument is passed through the mouth and down into the stomach. Special tools are used to remove the tumors.

The different types of techniques used are endoscopic mucosal resection, endoscopic submucosal resection, and endoscopic submucosal dissection (which is only done in certain places). The type of procedure will be dependent upon the location of the cancer, the facility where the procedure is done, and the opinion of the physicians.

Subtotal Gastrectomy

During this surgery, part of the stomach is removed. This procedure is most often done when the cancer is located in the part of the stomach that is closest to the small intestine (the distal part). The part of the stomach that contains the cancer plus some of the surrounding tissue and any lymph nodes that are involved will be removed.

Total Gastrectomy.

This surgery involves removing all of the stomach as well as any surrounding tissue and lymph nodes, as needed. Without a stomach, the esophagus will need to be connected to the small intestine. This surgery might be done more often for cancer that involves more of the stomach or that is at the top of the stomach closer to the esophagus.

Other Treatments

Besides surgery, other treatments include:

• Chemotherapy: Chemotherapy is used to kill cancer cells. It may be used without surgery, or before or after surgery. It may be used prior to surgery in order to shrink the cancer and make it easier to remove. It might be used after surgery in case any cancer cells were left. Chemotherapy may be given through pills or infusions into a vein.
• Radiation: Radiation is the use of targeted energy to kill cancer cells. It is administered with a machine. Patients will lie on a table and the machine will move around the body to direct the radiation. This treatment might be used before, during, or after surgery, or along with chemotherapy.
• Targeted drug therapy: Drugs that are designed to be more specific in how they attack cancer are called targeted drug therapy. This treatment might be used along with chemotherapy.
• Immunotherapy: In this treatment, drugs are used to stimulate the immune system to target the cancer cells and kill them. This treatment is used more often in advanced cancer.
• Palliative care: Supportive care may be given in order to relieve pain and discomfort. This type of care is used to improve quality of life while undergoing other treatments.

Prognosis

The prognosis for stomach cancer will depend on the stage of the cancer. Cancer that has spread outside the stomach, in general, may have a poorer prognosis. Stomach cancer may be put into a category, such as localized (cancer that hasn't spread outside the stomach), regional (cancer that has spread to nearby lymph nodes), or distant (cancer that has spread to organs further from the stomach).

Cancer survival rates are often given in terms of fvie years. The percentages are how many people, on average, are expected to live five years after being diagnosed with this type of cancer. The American Cancer Society gives the five-year survival rates for stomach cancer by category as:

• Localized: 69%
• Regional: 31%
• Distant: 5%
• All stages combined: 32%

Coping

Receiving a diagnosis of cancer can bring on strong emotions. It can also affect relationships with friends, family members, and co-workers. Having some tools to cope with the ups and downs of cancer treatment may help.

Learning as much as possible about the available treatments and what affects they may have is a helpful coping technique for some people. Understanding why doctors are making certain recommendations and what their effectiveness is can take some of the uncertainty out of the treatment journey. Bringing questions to appointments and making use of a patient portal or other tools can be helpful in getting answers.

Family and friends often want to help, either to lend an ear or to take over some of the tasks of everyday living. It may help to let others take over some routine chores such as shopping for food, cleaning the house or doing laundry, or running errands such as picking up prescriptions.

There are professionals available who are experienced in helping people who live with cancer in sorting through their problems and feelings. This can be a therapist, a social worker, or a clergyperson.

If more help is needed, a professional can also help in making recommendations on where to receive it, such as if family support is needed. Cancer support groups may also be helpful for some people who find comfort in talking to others coping with a similar diagnosis.

A Word From Verywell

Because stomach cancer is not common, there is no routine screening done for it. Symptoms of stomach cancer that go on for a few weeks are a reason to talk to a doctor to find out if there's a need to do further testing.

People who are at increased risk for stomach cancer might receive regular testing, however, in order to catch the disease early if it does start to develop. Not smoking, eating a diet rich in fruits and vegetables, and receiving regular treatment for related conditions are helpful in reducing the risk from cancer.