(a)
Recently, the top New England Journal of Medicine published a heavyweight study from South Korea:Proving that people with a family history of stomach cancer who carry H. pylori have up to a 73% reduced risk of getting stomach cancer if the infection is eradicated!
To my knowledge, this is the strongest evidence to date to support the eradication of H. pylori in this group of people at high risk for gastric cancer.
This study is important for the Chinese because China has one of the highest rates of stomach cancer in the world!
China has 20% of the world’s population, but 44% of the incidence of stomach cancer and 50% of the deaths!
The two major risk factors for gastric cancer are H. pylori infection and family history.
The two major risk factors for gastric cancer are H. pylori infection and family history.
The World Health Organization has long designated H. pylori as a class I carcinogen, as numerous studies have shown that infected individuals are 3 to 6 times more likely to get stomach cancer than the general population. Long-term H. pylori infection may lead to chronic gastritis, which stimulates cellular mutation and growth. Over time, this increases the risk of cancer.
It is estimated that half of all adults in China are carriers of H. pylori. In contrast, developed countries in Europe and the United States have far fewer infections and far less stomach cancer.
Family history, another important risk factor for gastric cancer.
If a person has an immediate family member (parent, brother, child) who has stomach cancer, he/she has 2 to 3 times the risk of getting stomach cancer than the average person!
Why are people with a family history of stomach cancer more likely to get it?
Because people share a number of risk factors, both endogenous and exogenous. The endogenous factors are mainly genetic, for example, the family may carry genes that make them more likely to get stomach cancer. And exogenous factors are mainly environmental and lifestyle factors, including unhealthy eating habits, but also H. pylori infection.
(ii)
It should be noted that although H. pylori is a class I carcinogen, it remains somewhat controversial whether every infected person needs to have the bacteria killed.
Particularly for the general population without symptoms, some experts would recommend no rush to eradicate, observation-based, and timely screening.
The reason for this is that these people are already at low risk for gastric cancer and therefore have limited benefit, and some studies have found that using high-dose antibiotics to eradicate H. pylori can potentially cause other risks in an otherwise healthy population, resulting in more harm than good.
But for people at high risk of gastric cancer, almost all official organizations recommend eradication because the benefits outweigh the harms!
Who are the high-risk groups? These include the following four major groups:
- Have a family history of gastric cancer
- Have peptic ulcers
- Has chronic gastritis
- Has had a stomach-related tumor
So what are the results after eradication? How much benefit is there?
To answer these questions, the Korean researchers designed a rigorous double-blind trial. This is one of the rarer large-scale double-blind trials of cancer prevention.
A total of 1,676 middle-aged adults (40 to 65 years old) with a history of gastric cancer in their families who also had H. pylori infection were enrolled in the trial, with more than 800 receiving antibiotic eradication and more than 800 receiving placebo.
The researchers then watched this group for an average of more than 9 years, checking every 2 years for the development of gastric cancer.
And the results?
Of the more than 800 people treated, 10 got stomach cancer, or 1.2%, and the people on the placebo? 23 people got stomach cancer, or 2.7%.
So, treating H. pylori has reduced the incidence of stomach cancer by 55% overall!
A 55% drop seems good enough, but researchers soon found out: that figure is still an underestimate!
The reason is that follow-up tests revealed that medication was not 100% efficient at eradicating H. pylori. Of the 10 people who were treated but still had gastric cancer, 5 did not actually succeed in eradicating it! They were still positive for H. pylori.
Overall, of the more than 800 people treated, only about 600 were actually cured. Five of them had stomach cancer, so the incidence was only 0.8%.
According to this, after successful eradication of H. pylori, the risk of gastric cancer in these people is actually reduced not by 55%, but by 73%!
This prevention effect is very significant!
While there are some short-term side effects associated with treatment with antibiotics, this trial did not find that eradicating H. pylori posed an additional risk of fatalities. Therefore, for people at high risk with a family history, eradication treatment is significantly more beneficial than harmful.
If there were reservations about eradicating H. pylori in the general population, this data proves that for people with a family history of gastric cancer and H. pylori infection, there is no hesitation, just two words: eradicate!
(iii)
How can H. pylori be eradicated?
It’s not that hard. It’s a triple or quadruple therapy based on antibiotics, which usually takes 7 to 14 days.
Triple therapy is with two antibiotics + (for example, amoxicillin + clarithromycin) + a proton pump inhibitor. The improved version of quadruple therapy adds another drug: bismuth.
Treatment is good in either triple or quadruple combination. Quadruple therapy has a somewhat higher eradication rate than triple therapy, reaching over 90%.
But as I said earlier, it is not 100% effective anyway, so you should go back a month after the treatment is finished to check if the eradication is successful.
(Photo from station cooler Helo)
What if the treatment fails?
For people who have incomplete eradication, there are options to adjust the medication, such as choosing other antibiotics for treatment.
Also, the treatment process is likely to have side effects such as imbalance of intestinal flora because of the heavy use of antibiotics, and sometimes doctors will recommend using some probiotics in combination to relieve symptoms such as diarrhea.
If you are a high-risk group and H. pylori has never been eradicated, are you dead?
Of course not.
Another statistic in this article that is of interest is that in the entire trial, although 33 people were found to have stomach cancer, none of them died from it, even those who did not receive H. pylori treatment. Why?
Because all the ones detected were early-stage (stage I/II) gastric cancer, and none of them were advanced!
Why were they all early stage?
So the trial was designed so that all participants in the trial were required to have a gastroscopy every 2 years!
This again proves that in addition to eradicating H. pylori, regular gastroscopy screening is valuable and necessary for people at high risk for gastric cancer.
Gastric cancer prevention can be divided into two levels, with H. pylori eradication as primary prevention and gastroscopy screening as secondary prevention.
Even if H. pylori is not cleared, there is no need to panic, just make sure you do your own screening for gastric cancer, especially gastroscopy. As long as it doesn’t drag on to an advanced stage, gastric cancer is still very treatable and doesn’t amount to a terminal disease!
Japan has a high incidence of gastric cancer, but the mortality rate is much lower than ours, and it is important that both primary and secondary prevention are done better.
I believe that as the economy, medical care and education improve, the situation in China will slowly improve as well. In the near future, stomach cancer can become a rare disease that can be prevented and controlled!