The factor inflating H. pylori’s gastric cancer risk by 45%

About half the world’s population harbors a nasty bacterium in their gut known as H. pylori, short for Helicobacter Pylori.

In most individuals, it doesn’t usually cause any symptoms, but when it does, H. pylori is behind all sorts of gastric problems, like heartburn, indigestion, and gastritis (inflammation of the stomach).

Left untreated, H. pylori can also lead to more serious problems like peptic ulcers and gastric (stomach) cancer.

Until now, prevention of gastric cancer was limited to testing for and treatment of H. pylori infections.

But a breakthrough study has found that genetics plays a much larger role in stomach cancer than we thought — and that this opens up brand new avenues for prevention.

H. pylori: a high-level carcinogen

In 2005, two Australian scientists shared the Nobel prize for their discovery that H. pylori was the cause of most stomach ulcers, shattering the notion that ulcers were mainly due to stress.

Because of this discovery, H. pylori was soon linked with gastric cancer in a big way. It was classified as a “high-level” carcinogen, along with smoking for lung cancer and overexposure to sunlight for skin cancer.

Genetics was never thought to play a part in gastric cancer. But a breakthrough study has proven that, when combined with the presence of H. pylori, the presence of certain genetic factors sends your chances of getting gastric cancer through the roof.

Double whammy: bacteria plus genetic variants

After analyzing DNA samples from 12,000 patients with gastric cancer and more than 44,000 people without cancer, scientists from Japan’s RIKEN Center for Integrative Medical Science have identified nine high-risk gastric cancer genes.

These include the BRCA1 and BRCA2 genes, also linked to breast, ovarian, prostate and pancreatic cancer, and the MLH1, MSH2 and MSH6 genes that increase the risk of colorectal cancer.

“I suspected there might be an interaction between the gene variants and H. pylori on gastric cancer risk,” says Yoshiaki Usui, one of the study’s lead researchers. “But the actual impact was much larger than I had imagined.”

Here’s what they found…

• The probability of someone getting gastric cancer was less than five percent regardless of genetics if they did not carry the H. Pylori bacterium.
• This risk increased to 14 percent for those who did carry the bacterium, but not one of the rare, high-risk genetic variants.
• But the real surprise was that, for those who had both H. pylori, plus one of those genetic variants, the risk of gastric cancer in their lifetime jumped to 45 percent!

Clear the infection to lower cancer risk

There is some good news in all of this.

Knowing that there are two different factors at play in gastric cancer risk — bacteria and genetics — gives us another opportunity for prevention.

If you are carrying one of the nine gene variants, you can be tested for H, pylori infection and can eliminate the bacterium, thus dramatically reducing your risk of developing gastric cancer. H. pylori can be easily treated with antibiotics.

This really pleases geneticist Yukihide Momozawa.

“As a geneticist, a lot of my work involves identifying genetic risk, and sometimes we can provide only an assessment of risk to carriers, which isn’t very satisfying,” he says. “But this time we can provide genetic risk and an effective treatment. That’s a key point of this study.”

Maybe you don’t have a genetic variant but would still like to rid yourself of H. pylori without antibiotics. A report in the World Journal of Gastroenterology lists some natural remedies that diminish this bad bacteria including probiotics, broccoli sprouts, green tea, licorice, red wine (in moderation) and honey.

Also, common sense precautions like hand washing, drinking filtered water, and washing fruits and vegetables couldn’t hurt.

Sources:

Beware the Horrifying Double Whammy That Inflates Gastric Cancer Risk by 45% — SciTech Daily

Helicobacter pylori, Homologous-Recombination Genes, and Gastric Cancer — The New England Journal of Medicine