Digestive Diseases: Stomach (Gastric) Cancer

Cancer of the stomach, also called gastric cancer, is a malignant tumor arising from the lining of the stomach. According to the National Cancer Institute (NCI), the estimated numbers of new cases and deaths from gastric cancer in the United States in 2005 were:

• New cases: 21,860
• Deaths: 11,550

The NCI also reports that gastric cancer now ranks 14th in incidence among the major types of cancer malignancies in the US.

Stomach cancers are classified according to the type of tissue where they originate. The most common type of stomach cancer is adenocarcinoma, which starts in the glandular tissue of the stomach and accounts for 90 to 95% of all stomach cancers. Other forms of stomach cancer include lymphomas, which involve the lymphatic system, and sarcomas, which involve 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 when discovered

What Causes Stomach Cancer?

The exact cause of stomach cancer is unknown, but a number of conditions can increase the risk of the disease. These include:

• Helicobacter pylori (H. pylori) infection of the stomach. H. pylori is a bacterium that infects the lining of the stomach and causes chronic inflammation and ulcers.
• Advanced age.
• Male gender.
• A diet low in fruits and vegetables.
• A diet high in salted, smoked or preserved foods.
• Chronic gastritis.
• Pernicious anemia.
• Some gastric polyps.
• Family history of gastric cancer.
• Smoking.

What Are the Symptoms of Stomach Cancer?

In the early stages of stomach cancer, you may have very few symptoms. These may include:

• Indigestion and stomach discomfort
• A bloated feeling after eating
• Mild nausea
• Loss of appetite
• Heartburn

These symptoms are similar to those caused by a peptic ulcer. If you are experiencing any of these symptoms you should see a doctor so that a proper diagnosis can be made and timely treatment given. A stomach cancer can grow very large before it causes other symptoms.

In more advanced cancer, you may have:

• 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 (a deficiency in red blood cells).

How Is Stomach Cancer Diagnosed?

There has been a significant decrease in the number of people diagnosed with stomach cancer in the past 60 years, but it is still the seventh leading cause of cancer deaths in the U.S. Various medical conditions can be associated with an increased risk of developing stomach cancer, including gastritis, pernicious anemia (a deficiency of vitamin B12 in the blood), gastric polyps (growths of tissue in the stomach) and gastric (peptic) ulcer. In addition, a person's risk of developing stomach cancer has been found to be greater if he or she has been infected with H. pylori bacteria.

Other people who may be at an increased risk include:

• People who use tobacco or drink alcoholic beverages regularly
• Workers in certain industries, including those in the coal mining, nickel refining, and rubber and timber processing industries.
• Workers exposed to asbestos fibers