Yes, infection with Helicobacter pylori H. What is H. The infection is no longer common in the UK. How can H. What cancers are linked to H. Key references. International Agency for Research on Cancer. Last reviewed 6 September In addition, the helical shape of H. Although immune cells that normally recognize and attack invading bacteria accumulate near sites of H. In addition, H. Although H. More information about H. Since then, it has been increasingly accepted that colonization of the stomach with H.
Infection with H. In most populations, the bacterium is first acquired during childhood. Infection is more likely in children living in poverty, in crowded conditions, and in areas with poor sanitation. Gastric cancer, or cancer of the stomach, was once considered a single entity. Now, scientists divide this cancer into two main classes: gastric cardia cancer cancer of the top inch of the stomach, where it meets the esophagus and non-cardia gastric cancer cancer in all other areas of the stomach.
Gastric cancer is the second most common cause of cancer-related deaths in the world, killing approximately , people in 3. Gastric cancer is less common in the United States and other Western countries than in countries in Asia and South America.
Overall gastric cancer incidence is decreasing. However, this decline is mainly in the rates of non-cardia gastric cancer 4. Gastric cardia cancer, which was once very uncommon, has risen in incidence in recent decades 5. Other risk factors for gastric cancer include chronic gastritis ; older age; male sex; a diet high in salted, smoked, or poorly preserved foods and low in fruits and vegetables; tobacco smoking; pernicious anemia ; a history of stomach surgery for benign conditions; and a family history of stomach cancer 6 , 7.
Whereas people infected with H. Epidemiologic studies have shown that individuals infected with H. The risk increase appears to be restricted to non-cardia gastric cancer. For example, a combined analysis of 12 case—control studies of H. Additional evidence for an association between H. Comparing subjects who developed non-cardia gastric cancer with cancer-free control subjects, the researchers found that H. Several studies have detected an inverse relationship between H. The possibility of an inverse relationship between the bacterium and gastric cardia cancer is supported by the corresponding decrease in H.
Similar epidemiologic evidence suggests that H. For example, a large case—control study in Sweden showed that the risk of esophageal adenocarcinoma in H. A meta-analysis of 13 studies, including the Swedish study, found a 45 percent reduction in risk of esophageal adenocarcinoma with H.
Moreover, as with gastric cardia cancer, dramatic increases in esophageal adenocarcinoma rates in several Western countries parallel the declines in H.
Although it is not known for certain how H. This idea is supported by the finding that increased expression of a single cytokine interleukinbeta in the stomach of transgenic mice causes sporadic gastric inflammation and cancer The increased cell turnover resulting from ongoing cellular damage could increase the likelihood that cells will develop harmful mutations.
One hypothesis that may explain reduced risks of gastric cardia cancer and esophageal adenocarcinoma in H. This decline would reduce acid reflux into the esophagus, a major risk factor for adenocarcinomas affecting the upper stomach and esophagus.
Some H. This toxin known as CagA alters the structure of stomach cells and allows the bacteria to attach to them more easily.
Long-term exposure to the toxin causes chronic inflammation. However, not all strains of H. Epidemiologic evidence suggests that infection with cagA -positive strains is especially associated with an increased risk of non-cardia gastric cancer and with reduced risks of gastric cardia cancer and esophageal adenocarcinoma.
For example, a meta-analysis of 16 case—control studies conducted around the world showed that individuals infected with cagA -positive H. Conversely, a case—control study conducted in Sweden found that people infected with cagA -positive H. Similarly, another case—control study conducted in the United States found that infection with cagA -positive H. Recent research has suggested a potential mechanism by which CagA could contribute to gastric carcinogenesis.
In three studies, infection with CagA-positive H. Gastric MALT lymphoma is a rare type of non-Hodgkin lymphoma that is characterized by the slow multiplication of B lymphocytes , a type of immune cell, in the stomach lining. This cancer represents approximately 12 percent of the extranodal outside of lymph nodes non-Hodgkin lymphoma that occurs among men and approximately 18 percent of extranodal non-Hodgkin lymphoma among women If your child has been diagnosed with an ulcer or H.
Sudden, sharp abdominal pain. Blood in the stool or black feces. If you are infected with the bacteria you can get a painful sore called a peptic ulcer. These sores form in your upper digestive tract. But having good health habits hygiene can help keep you safe. These habits include:. Washing your hands with soap and water. It is very important to do this after using the bathroom and before eating. Once you know for sure that you have H. He or she will do some tests to make sure the bacteria has been removed.
Call your healthcare provider if your symptoms get worse or you have new symptoms. Call right away if you have symptoms such as bloody vomit, blood in your stools, or black, tarry-looking stools. It attacks your stomach and the first part of your small intestine duodenum. This can cause redness and swelling inflammation.
It may be passed or spread from person to person by mouth, such as by kissing. It may also be passed by direct contact with vomit or stool. At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you. Health Home Conditions and Diseases. What causes H. It may also be passed by having contact with vomit or stool. This may happen if you: Eat food that was not cleaned or cooked in a safe way Drink water that is infected with the bacteria Who is at risk for H.
You may be at greater risk for H. Most people first get the bacteria when they are children, but adults can get it too. It's not clear why this is, but some people may be born with more resistance to the harmful effects of H.
When signs or symptoms do occur with H. Make an appointment with your doctor if you notice any persistent signs and symptoms that worry you. Seek immediate medical help if you experience:. The exact way H. Risk factors for H. A peptic ulcer is a sore on the lining of your stomach, small intestine or esophagus. A peptic ulcer in the stomach is called a gastric ulcer. A duodenal ulcer is a peptic ulcer that develops in the first part of the small intestine duodenum.
An esophageal ulcer occurs in the lower part of your esophagus. Complications associated with H. In areas of the world where H. Whether there is a benefit to testing for H.
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