Stomach cancer, also known as gastric cancer, is a disease in which cancer cells first form in the stomach. In the United States, stomach cancer is the seventh leading cause of cancer deaths. Although the incidence of stomach cancer in the United States has decreased since the 1930s, this type of cancer is a major cause of death worldwide, especially in developing countries.
Understanding the Stomach
The stomach is a J-shaped hollow organ that is located in the upper abdomen. The stomach is the part of the
digestive system that processes nutrients from food and helps pass waste material out of the body. After the partly digested food leaves the stomach, it will pass into the small intestine and then into the large intestine.
The wall of the stomach is made up of three layers of tissue:
- The mucosal (innermost) layer
- The muscularis (middle) layer
- The serosal (outermost) layer.
The most common type of stomach cancer is gastric adenocarcinoma, or cancer of the glandular tissue in the stomach. Rare forms of stomach cancer include:
- Lymphomas -- cancers involving the lymphatic system (see Lymphoma)
- Sarcomas -- cancers of the connective tissue, such as muscle, fat, or blood vessels.
Stomach cancer can also affect nearby organs and lymph nodes. For example:
- A stomach tumor can grow through the stomach's outer layer into nearby organs, such as the pancreas, esophagus, or intestine
- Stomach cancer cells can spread through the blood to the liver, lungs, and other organs
- Stomach cancer cells also can spread through the lymphatic system to lymph nodes all over the body.
When stomach cancer spreads from its site of origin to another part of the body, the new tumor will have the same kind of abnormal cells and the same name as the original tumor. For example, if stomach cancer spreads to the liver, the cancer cells in the liver are actually stomach cancer cells -- not
liver cancer cells. Therefore, it will be treated as stomach cancer. Doctors may call the new tumor "distant" or metastatic disease.
For the remainder of this article, the term "stomach cancer" will be used to refer to gastric adenocarcinoma.
Studies have found a number of factors that may increase the risk of developing this type of cancer. Some of the risk factors for stomach cancer include:
- Helicobacter pylori infection of the stomach
- Chronic gastritis (inflammation of the stomach)
- Older age
- Being male
- A diet high in salted, smoked, or poorly preserved foods
- Pernicious anemia
- Smoking cigarettes
- Intestinal metaplasia
- Familial adenomatous polyposis (FAP) or gastric polyps
- A mother, father, sister, or brother who has had stomach cancer.
Risk factors are not causes of the disease. However, they can increase a person's chances of developing it. People who are at risk of developing stomach cancer should talk to their doctor about methods of prevention and plan a schedule for checkups.
(Click Stomach Cancer Risk Factors for more information.)
In the early stages of stomach cancer, the following symptoms may occur:
- Indigestion and stomach discomfort
- A bloated feeling after eating
- Mild nausea
- Loss of appetite
- Heartburn.
In more advanced stages, the following symptoms may occur:
- Blood in the stool
- Vomiting
- Weight loss for no known reason
- Stomach pain
- Jaundice (yellowing of eyes and skin)
- Ascites (build-up of fluid in the abdomen)
- Trouble with swallowing.
Other health problems, such as an ulcer or infection, can also cause symptoms of stomach cancer. People who have possible stomach cancer symptoms should see a doctor so that the problem may be diagnosed and treated.
(Click Stomach Cancer Symptoms for more information.)
In order to diagnose stomach cancer, doctors will typically need to perform a physical exam, ask for the patient's personal and family medical history, and perform additional tests and procedures that examine the stomach and esophagus. Doctors may also refer patients to a gastroenterologist, who is a doctor that specializes in diagnosing and treating digestive problems.
Tests and procedures that are used to make a stomach cancer diagnosis may include:
- Physical exam
- Blood tests
- Upper gastrointestinal (GI) series
- Endoscopy
- Biopsy
- Computed tomography (CT) scan.
After a healthcare provider makes the diagnosis, he or she will need to identify the stomach cancer stage in order to plan the best treatment. Staging is an attempt to find out the size of the tumor, whether the disease has spread, and if so, to what parts of the body.
Specific stages of stomach cancer include:
- Stage 0
- Stage I
- Stage II
- Stage III
- Stage IV
- Recurrent.
- The size and location of the tumor
- The stage of the cancer
- The patient's general health.
In general, treatment may include:
- Surgery
- Chemotherapy
- Radiation therapy.
Patients should work with their doctor to develop a treatment plan that meets their medical needs and personal values. Choosing the most appropriate treatment for stomach cancer is a decision that ideally involves the patient, the family, and the healthcare team.
A person's prognosis will depend on factors such as the stage of the cancer and on the patient's general health. Patients whose stomach cancer is found very early will have a greater chance of recovery. Stomach cancer that is diagnosed in the later stages can usually be treated but can rarely be cured.
Statistics on Stomach Cancer
The American Cancer Society estimated that 22,280 Americans (13,400 men and 8,880 women) would be diagnosed with stomach cancer in 2006 and that 11,430 American men and women would die as a result of the disease during the year. During 1995-2001, the survival rate for stomach cancer was 23.2 percent.
Key information about stomach cancer includes the following:
- Stomach cancer is a disease in which cancer cells form in the stomach.
- Age, diet, and stomach disease can affect a person's risk of developing stomach cancer.
- Possible signs of stomach cancer include indigestion, stomach discomfort, or pain.
- Tests that examine the stomach and esophagus are used to find and diagnose stomach cancer.
- Factors that will affect a person's prognosis and treatment options include such things as the stage of the cancer, the location of the tumor, and the patient's general health.
