Cancer of the stomach, also called gastric cancer, is a disease in which malignant cells arise from the lining of the stomach.
Stomach cancers can develop in any part of the stomach and then may spread throughout the stomach and to other organs. They are classified by the type of tissue in which they originate.
Types of Stomach Cancer:
- Adenocarcinoma is the most common type of stomach cancer. This cancer starts in the glandular tissue of the stomach and accounts for 95 percent of all stomach cancers.
- Lymphomas involve the lymphatic system
- Sarcomas affect the connective tissue, such as muscle, fat or blood vessels
Stomach cancer can often be cured if it is found and treated at an early stage. Unfortunately, the outlook is poor if the cancer is already at an advanced stage.
The exact cause of stomach cancer is unknown, but a number of conditions can increase the risk of the disease. Helicobacter pylori (H. pylori) infection of the stomach increases the risk of stomach cancer. H. pylori is a bacteria that infects the lining of the stomach and causes chronic inflammation and ulcers.
In the early stages of stomach cancer, a patient may have very few symptoms. Symptoms may include:
- Indigestion and stomach discomfort
- A bloated feeling after eating
- Mild nausea
- Loss of appetite
A gastric tumor can grow very large before it causes any other symptoms. Since these symptoms resemble those caused by a hiatal hernia or peptic ulcer, patients may not recognize the need to consult a doctor for a long time.
In more advanced stages, a patient may have the following symptoms:
- Discomfort in the upper or middle part of the abdomen
- Blood in the stool (which appears as black, tarry stools)
- Vomiting or vomiting blood
- Weight loss
- Pain or bloating in the stomach after eating
- Weakness or fatigue associated with mild anemia
There has been a significant decrease in stomach cancer cases in the past 60 years, but it is still the 7th leading cause of cancer deaths in the United States.
Various medical conditions can be associated with an increased risk of developing stomach cancer including:
- Pernicious anemia
- Gastric polyps
- Gastric (peptic) ulcer
Risk is also heightened in people who:
- Have been infected with H. pylori bacteria
- Use tobacco or drink alcoholic beverages regularly
- Work in certain industries, including coal mining, nickel refining, rubber and timber processing
- Have been exposed to asbestos fibers
Stomach cancer is found most often in people beyond age 55 and it more often affects men than women. The condition is more common in Japan, Korea, parts of Eastern Europe, and Latin America than it is in the United States and Canada. A diet of meat and fish preserved by drying, smoking, salting or pickling and foods that contain nitrates and salt may be connected to this finding. Eating fresh foods, especially fruits and vegetables, may offer some protection against the disease.
Some abnormalities may be found by a physician during a physical exam, but these findings generally indicate advanced stomach cancer. Some of these findings include enlarged lymph nodes, enlarged liver and increased fluid in the abdomen (ascites).
When a patient has some of the initial vague symptoms, such as indigestion, weight loss, nausea and loss of appetite, the doctor may order screening tests. These tests include:
- Upper GI series: These are X-rays of the esophagus and stomach (the upper gastrointestinal, or GI tract) after the patient drinks a barium solution. The barium outlines the stomach on the x-ray helping the doctor find tumors or other abnormal areas.
- Gastroscopy and biopsy: This test examines the esophagus and stomach using a thin, lighted tube called a gastroscope. It is passed through the mouth to the stomach and allows a doctor to look directly at the inside of the stomach. If an abnormal area is found, the doctor will remove some tissue to be biopsied. Gastroscopy and biopsy are the best methods of identifying stomach cancer because a biopsy is the only sure way to diagnose cancer.
Stomach cancer may be treated with the following, in combination or alone:
- Surgery, called gastrectomy, to remove all or part of the stomach, as well as some of the tissue surrounding the stomach
- Radiation therapy
- Biological therapy (natural substances are used to boost the body's immune system to fight certain illnesses)
During a gastrectomy, lymph nodes near the stomach are also removed and biopsied to check for cancer cells. Lymphoma of the stomach is more frequently treated by gastrectomy than adenocarcinoma of the stomach. Only about one-third of stomach cancer cases can be treated and cured surgically.
Cancer of the stomach is difficult to cure unless it is found at an early stage, before it has spread. Unfortunately, because early stomach cancer has few symptoms, the disease is usually advanced when the diagnosis is made. However, advanced stomach cancer can be treated and the symptoms can be relieved.