In China, the cancer risk for foreigners and locals alike is increased due to the presence of the Helicobacter pylori (H. pylori) bacterial infection.
“Almost 100% of tissue with stomach cancer contains Helicobacter pylori bacteria,” said Dr Ji Kai Yu, chair of the department of internal medicine at Beijing United Family Hospital and Clinics (BJU). “This [bacterium] is linked to chronic gastritis, peptic ulcer disease, and stomach cancer.”
Ji has over 12 years of experience in the fields of internal medicine, gastroenterology and hepatology. With this comes a deep understanding of the threat H. pylori poses to those who make China their home.
H. pylori is transmitted through contaminated food and water, causing inflammation in the inner lining of the stomach known as gastritis – a risk factor for stomach cancer. Over 80% of people infected with the bacterium show no symptoms, which increases the need for periodic screening, especially for those over the age of 50.
While things like family history and diet also contribute to stomach cancer risk, H. pylori is acknowledged as a special concern for those at-risk individuals living in China. Due to generally lower hygiene standards, 50% of China’s population is infected with the bacterium, Ji said. This compares to only 5% in the US and other Western nations.
Once infected, it is nearly impossible for the body to rid itself of H. pylori. The bacterium colonizes in the stomach and secretes enzymes that neutralize the stomach acid which would otherwise destroy it. From there, H. pylori begins to produce chemical toxins that damage the lining of the stomach directly, often triggering an immune system response that can lead to further damage.
While many people who have H. pylori in their stomach never actually get cancer, some fall victim to the condition without ever having been considered at risk. The cancer generally develops over a long period of time and is characterized by noticeable symptoms such as chronic discomfort.
A minimally-invasive procedure known as endoscopy is used to screen for digestive system disorders including stomach cancer. There are two types of endoscopy: gastroscopy and colonoscopy. A gastroscopy is used to screen the esophagus, stomach, and the first part of the small intestine. A colonoscopy is used to screen the colon for disorders like colorectal cancer.
Endoscopy involves a thin, tube-like instrument called an endoscope, which is used to examine the inside of the digestive tract. Specially designed surgical tools that allow for biopsies or other procedures can also be used if necessary.
In addition, there are accurate and simple tests available for the detection of H. pylori, including blood antibody tests, urea breath tests (UBT), and endoscopic biopsies.
While blood tests for H. pylori antibodies are easy to perform, their accuracy is questionable as these antibodies can persist for years after H. pylori has been eradicated by antibiotic treatment.
The best way to test for the bacteria is through a combination of UBT and endoscopy.
UBT is a safe and simple test that reveals the presence of H. pylori in the stomach. The test relies on using H. pylori to break down the chemical urea into carbon dioxide which is then absorbed into the stomach and eliminated from the body on one’s breath. Endoscopic biopsy takes a sample of tissue from the stomach to test for the presence of H. pylori in a lab.
If detected, H. pylori can be treated with a regimen of antibiotic drugs.
“The key is what stage the cancer is in,” Ji said. “The only way to cure cancer nowadays is through early diagnosis. [In these cases,] the prognosis is much, much better from the screening group, and is the most curable. Quality of life is much improved.”