At a Glance
- Risk factors for stomach cancer include Helicobacter pylori infection, long-term inflammation of the stomach, smoking, family history of stomach cancer, poor diet, lack of physical activity, or obesity.
- The most common symptoms are discomfort or pain in the stomach area, difficulty swallowing, nausea and vomiting, weight loss, feeling full or bloated after a small meal, vomiting blood or having blood in the stool.
- Until the late 1930s, stomach cancer was the leading cause of cancer deaths in the United States. Now, stomach cancer ranks 14th among the major types of cancer malignancies.
What Is Gastric Cancer?
Cancer that forms in tissues lining the stomach is called gastric or stomach cancer. Gastric cancer is much more common worldwide, particularly in less developed countries. In the United States, gastric cancer ranks 14th among the major types of cancer malignancies. Until the late 1930s, stomach cancer was the leading cause of cancer deaths in the United States. Now, stomach cancer is well down on this list.
The American Cancer Society’s most recent estimates for stomach cancer in the United States are for 2010:
- About 21,000 cases of stomach cancer will be diagnosed
- About 10,570 people will die from this type of cancer
The stomach is a hollow organ in the upper abdomen, under the ribs. It’s part of the digestive system. Food moves from the mouth through the esophagus to the stomach. In the stomach, the food becomes liquid. Muscles in the stomach wall push the liquid into the small intestine. The wall of the stomach has five layers:
- Inner layer or lining (mucosa): Juices made by glands in the inner layer help digest food. Most stomach cancers begin in this layer.
- Submucosa: This is the support tissue for the inner layer.
- Muscle layer: Muscles in this layer contract to mix and mash the food.
- Subserosa: This is the support tissue for the outer layer.
- Outer layer (serosa): The outer layer covers the stomach. It holds the stomach in place.
About Gastric Cancer
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old or get damaged, they die, and new cells take their place. Sometimes, this process goes wrong. New cells form when the body doesn’t need them, and old or damaged cells don’t die as they should. The buildup of extra cells often forms a mass of tissue called a growth, polyp, or tumor.
Tumors in the stomach can be benign or malignant. Benign tumors are not as harmful as malignant tumors. They can be removed and don’t spread to other parts of the body. Malignant tumors, however, may be a threat to life, may grow again after removal and may also spread to other parts of the body.
Stomach cancer usually begins in cells in the inner layer of the stomach. Over time, the cancer may invade more deeply into the stomach wall. A stomach tumor can grow through the stomach’s outer layer into nearby organs, such as the liver, pancreas, esophagus, or intestine. Stomach cancer cells can spread by breaking away from the original tumor. They enter blood vessels or lymph vessels, which branch into all the tissues of the body. The cancer cells may be found in lymph nodes near the stomach. The cancer cells may attach to other tissues and grow to form new tumors that may damage those tissues. The spread of cancer is called metastasis.
A risk factor is something that may increase the chance of getting a disease. People with certain risk factors are more likely than others to develop stomach cancer. Studies have found the following risk factors for stomach cancer:
- Helicobacter pylori infection: H. pylori is a bacterium that commonly infects the inner lining of the stomach. Infection with H. pylori can cause stomach inflammation and peptic ulcers.
- Long-term inflammation of the stomach: People who have conditions associated with long-term stomach inflammation (such as the blood disease pernicious anemia) are at increased risk of stomach cancer. People who had part of their stomach removed may have long-term stomach inflammation and increased risk of stomach cancer.
- Smoking: Smokers are more likely than nonsmokers to develop stomach cancer. Heavy smokers are at most risk.
- Family history: Close relatives of a person with a history of stomach cancer are somewhat more likely to develop the disease themselves. If many close relatives have a history of stomach cancer, the risk is even greater.
- Poor diet, lack of physical activity, or obesity:
- Studies suggest that people who eat a diet high in foods that are smoked, salted, or pickled have an increased risk for stomach cancer. On the other hand, people who eat a diet high in fresh fruits and vegetables may have a lower risk of this disease.
- A lack of physical activity may increase the risk of stomach cancer.
- Also, people who are obese may have an increased risk of cancer developing in the upper part of the stomach.