East Asian people are more likely to develop a more aggressive form of stomach cancer because of their greater likelihood of alcohol intolerance, according to a new study led by researchers in Japan.
The researchers’ findings, published this week in the scientific journal Nature Genetics, associate lower alcohol tolerance with a higher risk of diffuse gastric cancer, a rarer form of stomach cancer that affects more than one part of the stomach.
Dr. William Dahut, chief scientific officer of the American Cancer Society, said the study – which collected cells from nearly 1,500 stomach cancer patients in Japan, China, South Korea, Singapore and the US – is the first comprehensive genomic analysis of stomach cancer.
“There is an interesting combination between the development of mutations and a specific genotype in East Asians, which disrupts alcohol metabolism,” said Dahut, who was not involved in the study. “It seems like they have that genotype. They’re more likely to develop a tumor specific mutation.”
Populations in East Asia have long been disproportionately affected by stomach cancer compared to those of Western countries. Half of all stomach cancers worldwide occur in China, and it is the most common cancer in men in Japan. But in the United States, stomach cancer accounts for only about 1.5% of all new cancers diagnosed each year.
People of East Asian descent are much more likely to inherit a genetic mutation that is uncommon in other ethnic groups that compromises the ability to metabolize alcohol. This is the same mutation responsible for facial redness after drinking, often referred to as “Asian glow,” according to study co-author Tatsuhiro Shibata.
Shibata, chief of the Cancer Genomics division at Japan’s National Cancer Center Research Institute, said he hopes these findings make it easier for researchers to spot patterns in gastric cancer onset.
“We can develop a specific way to detect areas and maybe prevent certain cancers,” he said.
The inability of many East Asians to process alcohol properly causes it to sit in the stomach for a long time, making frequent drinkers more likely to develop chronic gastritis, said Ajay Goel, who studies the detection of gastrointestinal cancer at the City of Hope Medical Center in California and was not involved in the new study.
“That essentially leads to chronic inflammation in the stomach,” Goel said. “And eventually, after years and years of repeated exposure, these patients tend to get more stomach cancer.”
Stomach cancer cases are also statistically much more common in men than in women. But this makes sense from a behavioral perspective, Goel said, rather than being due to inherent genetic factors. Data shows that East Asian men consume significantly more alcohol than their female counterparts.
As with any cancer, early detection is crucial for gastric cancer treatment. But because of its relative rarity in the West compared to other types, such as breast, cervical, and colon cancer, the United States does not routinely screen for stomach cancer.
“It’s increasingly important information about the power of knowing one’s own genomics,” Dahut said.