An Investigation into the Recent Increase in Gastric Cancer in the USA.

Background: The USA has among the lowest gastric cancer incidence rates worldwide.

Aim: To investigate whether increasing immigration from high cancer incidence countries has altered the GC incidence in a large US metropolitan area.

Methods: This was a retrospective cohort study among an underprivileged, multiethnic population in Texas. Gastric cancer cases diagnosed during 2005-2015 were identified using the cancer registry of the public medical care system for Harris County. All cases were histologically confirmed; demographic and clinical data were obtained from review of electronic medical records. Census data were used to determine the distribution of the adult county population by race/ethnicity and age. Two time periods (2005-2009 and 2010-2015) were studied to correspond with census reporting intervals.

Results: In total, 299 cases were included: average age 55 years, 59% males and 63% Hispanics (predominantly recent immigrants of Central-American origin). The gastric cancer incidence remained stable among non-Hispanic Whites and Blacks but increased significantly among Hispanics (from 10 to 17 cases/100,000 persons/year, RR = 2.0, 95% CI 1.4-2.5, p = 0.001). Among Hispanics, gastric cancer incidence rose significantly among persons aged 40-59 years and ≥ 60 years and was likely to be at advanced stage at the time of diagnosis even in the younger age population.

Conclusion: Gastric cancer incidence significantly increased among Hispanics residing in Houston resulting in changes in gastric cancer incidence becoming more unevenly experienced across the US population. Consideration should be given to gastric cancer preventive efforts, especially among immigrant populations from high gastric cancer risk countries.