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H. Pylori and Gastric Cancer
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
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
cant 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 doesnt 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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