Gastric cancer is cancer that starts in the stomach.

Cancer - stomach; Stomach cancer; Gastric carcinoma; Adenocarcinoma of the stomach

• Abdominal fullness or pain, which may occur after eat a small meal
• Dark stools
• Difficulty swallowing, which becomes worse over time
• Excessive belching
• General decline in health
• Loss of appetite
• Nausea
• Vomiting, which may contain blood (See: Vomiting blood)
• Weakness or fatigue
• Weight loss

Several different types of cancer can occur in the stomach. The most common type is called adenocarcinoma, which starts from one of the common cell types found in the lining of the stomach.

This article focuses on adenocarcinoma of the stomach.

Adenocarcinoma of the stomach is a common cancer of the digestive tract worldwide, although it is uncommon in the United States. It occurs most often in men over age 40. This form of gastric cancer is very common in Japan, Chile, and Iceland.

The rate of most types of gastric adenocarcinoma in the United States has gone down over the years. Experts think the decrease may be because people are eating less salted, cured, and smoked foods.

You are more likely to get gastric cancer if you:

• Have a family history of gastric cancer
• Have an infection of the stomach by bacteria called Helicobacter pylori
• Had a polyp larger than 2 centimeters in your stomach
• Have inflammation and swelling of the stomach for a long time (chronic atrophic gastritis)
• Have pernicious anemia
• Smoke

Diagnosis is often delayed because symptoms may not occur in the early stages of the disease. Or, patients may self-treat symptoms that gastric cancer has in common with other, less serious gastrointestinal disorders (bloating, gas, heartburn, and a sense of fullness).

The following tests can help diagnose gastric cancer:

• Complete blood count (CBC) to check for anemia
• Esophagogastroduodenoscopy (EGD) with biopsy to examine the stomach tissue
• Stool test to check for blood in the stools

Surgery to remove the stomach (gastrectomy) is the only treatment that can cure the condition. Radiation therapy and chemotherapy may help. For many patients, chemotherapy and radiation therapy after surgery may improve the chance of a cure.

For patients who cannot have surgery, chemotherapy or radiation can improve symptoms and may prolong survival, but will likely not cure the cancer. For some patients, a surgical bypass procedure may relieve symptoms.

The outlook varies. Tumors in the lower stomach are cured more often than those in the higher stomach -- gastric cardia or gastroesophageal junction. How far the tumor invades the stomach wall and whether lymph nodes are involved when the patient is diagnosed affect the chances of a cure.

When the tumor has spread outside the stomach, a cure is not possible and  the goal of treatment is to improve symptoms.

Call your health care provider if symptoms of gastric cancer develop.

Mass screening programs have been successful at detecting disease in the early stages in Japan, where the risk of gastric cancer is much higher than in the United States. The value of screening in the United States and other countries with lower rates of gastric cancer is not clear.

The following may help reduce your risk of gastric cancer:

• Don't smoke
• Eat a healthy, balanced diet rich in fruits and vegetables
• Take a medication to treat reflux disease, if you have it

Rustgi AK. Neoplasms of the stomach. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 202.

Gunderson LL, Donohue JH, Alberts SR. Cancer of the stomach. In: Abeloff MD, et al., eds. Abeloff's Clinical Oncology. 4th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 79.

National Cancer Institute. Gastric cancer treatment PDQ. Updated July 8, 2010.