Stomach Ulcers and Lymphoma

In a small number of people, H. pylori infection contributes to more serious illness.

Stomach ulcers affect millions of Americans. While they can be serious and even life threatening in some cases, most are managed effectively and without issue.

Most Stomach Ulcers are Not Cancerous

Ulcers are breaks or erosions in the lining of the stomach. Most stomach ulcers, or gastric ulcers, are not gastric cancer. There's an important link between Helicobacter Pylori, or H. pylori -- a bacterium associated with stomach ulcers -- and several stomach illnesses, including gastric cancer and primary stomach lymphoma.

Stomach Ulcers

In the 1990s, a stomach condition called atrophic gastritis, caused by the bacterium H. pylori, was proposed as a likely cause for both gastric ulcers and gastric cancer. Atrophic gastritis may have other causes as well.

A study from that time was done in a Swedish population, with 29,287 people who had gastric ulcers. They were followed for an average of 8.3 years, and stomach cancer, or gastric cancer, developed in 782 of them -- a higher proportion than would be expected.

Researchers calculated that the risk of developing gastric cancer over 3 years of follow up was 10 times higher in those with stomach ulcers than in the general population.

Stomach ulcers, stomach cancer and primary stomach lymphoma are all believed to have certain causative factors in common. The presence of H. pylori in the stomach is one of them, but that is certainly not the end of the story.

H. Pylori

H.

pylori are bacteria that circumvent the highly acidic environment of the stomach using their flagella to burrow into the mucus lining. H. pylori is thought to spread through contaminated food and water and through direct mouth-to-mouth contact. Present and growing in about half of the human population, these bacteria are introduced into the stomach and make themselves at home there early in life -- almost always before the age of 10 years.

They generally stay there for a lifetime, unless eliminated by an exposure such as antibiotic therapy.

Although H. pylori can persist for years without seeming to cause any problems, almost all people infected with this organism are believed to have some at least some degree of continuous inflammation in their stomachs. Not everyone responds to H. pylori or its inflammatory chemical signals in the same way, however.

According to the May 2013 issue of “Gastroenterology,” H. pylori typically typically is associated with an increased risk of gastric ulcers, gastric cancer and a type of gastric lymphoma. Individuals infected with H. pylori have a 10 to 20 percent lifetime risk of developing peptic ulcers and a 1 to 2 percent risk of acquiring stomach cancer.

Stomach Lymphoma – Gastric MALT

The official name is “marginal zone lymphoma of mucosa-associated lymphoid tissue.” A kind of stomach lymphoma, primary gastric MALT lymphoma is a rare type of non-Hodgkin lymphoma. It accounts for fewer than 1 in 20 cancers that start in the stomach.

Gastric MALT lymphoma involves B-lymphocytes, a type of immune cell, in the stomach lining.

Lymphomas usually arise in the lymph nodes, but sometimes they originate elsewhere in the body, outside the lymph nodes, and this is referred to as extranodal lymphoma. Gastric MALT lymphoma makes up about 12 percent of all extranodal non-Hodgkin lymphomas that occur in men and about 18 percent in women, according to the National Cancer Institute.

Normally, the lining of the stomach lacks lymphoid, or immune-functioning tissue, but H. pylori can stimulate the development of such tissue, and this is a normal response. It is very rare for this tissue to transform into MALT lymphoma. However, nearly all patients with gastric MALT lymphoma show signs of H. pylori infection. The risk of developing this tumor is more than 6 times higher in infected people than in uninfected people.

H. Pylori in Gastric MALT Lymphoma

Some 72 to 98 percent of patients with gastric MALT lymphoma are infected with H. pylori. A successful treatment of H. Pylori with antibiotics, causes the gastric lymphoma to regress in 70 to 80 percent of cases. The time between eradication of the H. pylori infection and disappearance of the lymphoma can vary quite a bit, depending on the individual and the lymphoma. If the H. pylori treatment is successful, no other treatment may be required.

Some people don’t respond to the elimination of H. pylori, alone. In these cases, they need to have more conventional therapies such as chemotherapy or radiotherapy, which are very effective for gastric MALT lymphoma.

Most of the patients whose lymphomas do respond to eliminating H. pylori stay in remission for several years. Long-term experience in people treated with antibiotics alone is still limited, though.

Sources and Background on Stomach Ulcers and Lymphoma:

For more background on H. pylori, stomach ulcers, gastric cancer and gastric lymphoma, explore the following sources:

National Cancer Institute. Helicobacter pylori and Cancer.

Lymphoma Association (UK). Gastric MALT lymphoma.

Hansson LE, Nyrén O, Hsing AW, et al. The risk of stomach cancer in patients with gastric or duodenal ulcer disease. N Engl J Med. 2006; 335:242-249.

Cover TL, Blaser MJ. Helicobacter pylori in health and disease. Gastroenterology. 2009;136(6):1863-1873.

Suerbaum S, Michetti P. Helicobacter pylori infection. N Engl J Med. 2002;347:1175–1186.

Sagaert X, Van Cutsem E, De Hertogh G, et al. Gastric MALT lymphoma: A model of chronic inflammation-induced tumor development. Nature Reviews Gastroenterology & Hepatology. 2010; 7(6):336–346.

Atherton JC. The pathogenesis of Helicobacter pylori-induced gastro-duodenal diseases. Annu Rev Pathol. 2006;1:63–96.

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