H. Pylori and Gastric Cancer

H. Pylori and Gastric Cancer

Published: October, 2001

Studies have linked Helicobacter pylori (H. pylori) infection with the development of gastric (stomach) cancer. H. pylori is a spiral-shaped bacterium that lives in the stomach and duodenum (the section of intestine just below the stomach). It has the ability to adjust to the harsh conditions in the stomach. H. pylori is believed to be transmitted orally.

Recently, researchers in Japan sought to clarify this association and explore which, if any, gastrointestinal conditions increase a person's risk of developing gastric cancer. The results of this study appeared in the September 13, 2001, issue of the New England Journal of Medicine.

The participants had duodenal (in the duodenum) ulcers, gastric ulcers, gastric hyperplasia (abnormal cell growth), or nonulcer dyspepsia (stomach pain). They underwent endoscopy — for the early detection of cancer — at enrollment and again during the next three years. Of the 1,526 who took part in the study, 1,246 had H. pylori infection and 280 did not.

Thirty-six of the H. pylori-infected patients developed gastric cancer versus none of the uninfected patients. Patients with H. pylori and significant gastric disorders had a significantly higher risk of developing gastric cancer. However, no gastric cancer was found in people with duodenal ulcers — despite being H. pylori-positive. This supports the notion that duodenal ulcers are related to a low risk of gastric cancer.

Results of the study — supported by a 1998 study in which 98% of patients with gastric cancer were H. pylori-positive — suggests gastric cancer develops almost exclusively in people infected with the bacterium.
October 2001 Update

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H. pylori Infection May Aggravate GI Injury in Patients Taking Low-dose Aspirin

Doctors commonly prescribe low-dose aspirin for the prevention of heart disease, but it may also be responsible for some potentially serious side effects when taken frequently. Among the most common of these are gastrointestinal erosions and ulcers.

A recent study in The American Journal of Gastroenterology sought to determine whether certain people taking low-dose aspirin — specifically, people infected with Helicobacter pylori, a common bacterium that can cause ulcers — are more susceptible to gastrointestinal erosions and ulcers than people who are not infected with H. pylori.

Researchers from the University of Texas Southwestern Medical School and Baylor College of Medicine recruited 61 healthy volunteers between the ages of 18 and 61. Of these, 29 volunteers were infected with H. pylori. Forty-six of the volunteers were then randomly selected to receive low-dose aspirin (either 81 mg daily or 325 mg every three days), while 15 received a placebo.

After 46 days of treatment, an upper GI endoscopy was performed on each subject to determine the extent of gastrointestinal injury. The researchers did not detect any injury in the stomach or duodenum (upper intestine) of the patients taking placebo. In the subjects taking aspirin, those patients who were infected with H. pylori were significantly more likely to have gastrointestinal injury than those who were not infected (50% vs. 16%).

However, there was no difference between the groups in complaints of pain, nausea, vomiting, indigestion, or heartburn. In addition, the difference in outcomes between patients taking 81 mg of aspirin daily and 325 mg every three days was not statistically significant.
The researchers caution that the results of this study may not hold for older people or those with gastrointestinal diseases such as peptic ulcer disease, because the volunteers were healthy and aged 61 or younger. However, this study does suggest eradicating H. pylori infection may help prevent gastrointestinal erosions and ulcers in patients taking low-dose aspirin on a long-term basis.
October 2001 Update

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Surgery for GERD

In recent years, people suffering from severe, chronic heartburn that can’t be controlled with medications have turned to surgery with hopes for permanent relief and the prevention of esophageal cancer. But the results of a recent study that assessed the well being of patients a decade after they had surgery question its benefits.

Heartburn, also known as gastroesophageal reflux disease (GERD), occurs when the opening between the esophagus and stomach relaxes spontaneously, allowing acidic gastric juices to flow into the esophagus and cause irritation. Medications for GERD include antacids, proton pump inhibitors that decrease the amount of acid produced, and drugs that increase the tightness of the esophageal. Surgery, an option usually reserved for hard-to-treat GERD, involves folding the top of the stomach around the end of the esophagus to create a tighter opening. This procedure has become more popular with the development of minimally invasive techniques.

A study from the late 1980s of 247 heartburn patients found surgery was better than medication at controlling symptoms. However, ten years later a follow-up study of 239 of the original patients found many of the patients who underwent surgery still suffered from heartburn. Though their symptoms were less intense than those who received medication in the original study, 62% of the surgical patients still took antireflux medication regularly (compared to 92% of the medical patients).

The study also found that surgery failed to significantly decrease the risk for esophageal cancer compared to treatment with medication. Chronic heartburn is a risk factor for this cancer. However, the small size of the study combined with the low incidence of esophageal cancer did not rule out the possibility of a difference. A more surprising result of the study showed surgical patients were more likely to die than patients on medication. These deaths were not related to the surgery, but close to half (48%) were related to heart disease. The researchers were unprepared for this result and therefore have no data to explain this finding.

The results of this study suggest that while surgery may do a better job at controlling the symptoms of heartburn, it doesn’t eliminate the need for medication or decrease cancer risk. In general, surgery should be seen as an option of last resort for those patients whose symptoms are hard to treat with medication.
June 2001 Update

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Killing H. Pylori Helps Prevent Gastrointestinal Bleeding in Patients Taking Low-Dose Aspirin

Many people take low-dose aspirin on a daily basis to help prevent heart attacks. Others take larger doses of stronger nonsteroidal antiinflammatory drugs (NSAIDs), such as naproxen (Anaprox, Aleve, others), to relieve musculoskeletal pain such as that caused by arthritis. When taken on a regular basis, however, NSAIDs often cause ulcers and gastrointestinal (GI) bleeding. Ulcers, which are raw, crater-like breaks in the mucosal lining of the digestive tract, may also be caused by excess acid production and a bacterium known as Helicobacter pylori (H. pylori).

In a study published in the New England Journal of Medicine, researchers enrolled 400 patients with a history of GI bleeding who were taking aspirin or other NSAIDs to prevent heart disease or to control musculoskeletal pain. They set out to find whether eradicating H. pylori infection reduces the risk of recurrent GI bleeding in these patients. For six months, 250 patients were given an 80 mg "baby" aspirin once per day, while the remaining 150 patients received 500 mg of naproxen twice per day. Within each of the two groups, patients were randomly assigned to take either a daily dose of omeprazole (Prilosec), an acid-suppressing medication, or a one-week antibiotic treatment to eradicate H. pylori infection, followed by placebo for the remainder of the trial.

The researchers found that in patients taking aspirin, those who were treated for H. pylori had a 1.9% risk of GI bleeding while the risk for those taking omeprazole was 0.9%. In other words, for patients on low-dose aspirin, the treatments were almost equal.

The results were very different for patients taking naproxen. 19% of the naproxen patients who had H. pylori treatment suffered from recurrent bleeding. In contrast, only 4% of the omeprazole group did.

The study suggests that patients with a history of GI bleeding who take low-dose aspirin to prevent heart attacks should be tested for H. pylori infection and treated if the infection is found to be present. Patients taking non-aspirin NSAIDs and who have experienced GI bleeding are more likely to benefit from acid-suppressing therapy.
April 2001 Update

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