Study looks into specific site gastric cancer risks among ethnic populations

Reviewed by Emily Henderson, B.Sc.Aug 6 2020

Non-white Americans, especially Asian Americans, are at disproportionately higher risk for gastric cancer compared to non-Hispanic white Americans. A new study breaks down this risk according to specific ethnicities and locations within the stomach.

The study published Aug. 6 in Gastroenterology analyzed California Cancer Registry data for the seven largest Asian American populations (Chinese, Japanese, Korean, Filipino, Vietnamese, South Asian and Southeast Asian) as well as for non-Hispanic whites, non-Hispanic blacks and Hispanic populations.

The population-based study revealed that non-white race and ethnic groups had a several-fold higher risk of developing stomach cancer in the main area of the stomach (noncardia gastric cancer) compared to the non-Hispanic white population. This risk was most striking among Korean Americans age 50 and older, who demonstrated a 12-fold to 14.5-fold higher risk compared to non-Hispanic whites. This is the most common location for stomach cancer to develop. However, Asian Americans -- with the exception of Japanese American men -- had a lower risk than non-Hispanic whites of developing gastric cancer in the upper portion of the stomach where it joins the esophagus (cardia gastric cancer).

We specifically chose to analyze individuals age 50 years and older since this is the age group for whom average-risk colorectal cancer screening and high-risk esophageal cancer screening is recommended. Unfortunately, even though certain ethnic groups have rates of gastric cancer that even exceed colorectal cancer, and even though gastric cancer is more common than esophageal cancer, screening for gastric cancer does not yet occur in the United States among high-risk groups. We are hopeful that the findings of this study will break the inertia surrounding gastric cancer screening."

Shailja Shah, MD, MPH, Assistant Professor of Medicine, study's lead author and corresponding author

The research sets the stage for developing targeted risk reduction programs for gastric cancer in the United States. Shah and colleagues recently published two studies demonstrating that gastric cancer screening starting at age 50 old in non-white race and ethnic groups is cost-effective. Shah was also one of the lead members of the American Gastroenterology Association's Technical Review team on gastric intestinal metaplasia (gastric precancer) surveillance for early gastric cancer detection. Shah's research is set on developing a strong foundation of evidence to establish screening guidelines for gastric cancer in the United States, where the number of people at risk for the cancer is increasing as the nation's population becomes more diverse.

Worldwide, gastric cancer is the fifth most common cancer and third leading cause of cancer-related death. In the United States, gastric cancer ranks 15th among cancers, but it afflicts population groups disproportionately.

The study in Gastroenterology revealed that for gastric cancer in the main area of the stomach, the incidence rate for Korean Americans was 49 cases per 100,000 people, 23.9 for Vietnamese Americans, 21.1 for Southeast Asian Americans (Cambodian, Laotian, Hmong and Thai), 19.2 for Japanese Americans, 17.6 for Chinese Americans, 14.0 for Hispanic Americans, 11.2 for non-Hispanic black Americans, 7.75 for South Asian Americans, 6.69 for Filipino Americans and 3.7 for non-Hispanic white Americans.

Men had significantly higher rates of gastric cancer compared to women. For instance, the rate for gastric cancer in the main area of the stomach was 70.0 per 100,000 for Korean American men compared to 33.5 for Korean American women.

"The immediate need for gastric cancer prevention and early detection efforts in the U.S. is amplified when considering that the pool of at-risk individuals is only expected to grow, with non-Hispanic whites now considered the minority population in 35 of the 50 largest cities and projections that non-Hispanic whites will no longer be the overall majority population by 2065," Shah said.