We read with great interest the retrospective cross-sectional study on multiethnic population in the United States (1). Tan and colleagues found that ethnicity and birthplace would be associated with the increased risk of gastric intestinal metaplasia (GIM). GIM is known as a precancerous lesion of noncardia gastric cancer and associated with Helicobacter pylori-related inflammatory injury. Hispanics born outside the United States were at increased risk of GIM, but it was independent of H. pylori infection status—namely, ever, current, or negative. Thus, the authors concluded that birthplace might be more informative than race/ethnicity to identify high-risk subpopulation of gastric cancer.
We quite agree that it should be a well-designed study and provided useful findings for a tailored massive screening and surveillance program to early detect gastric cancer. Identification of risk factors of gastric precancerous lesions and gastric cancer is meaningful to make the screening program efficient and cost-effective. Therefore, the cancer prevention and control plan can be improved and updated by focusing on subpopulation with high-risk features.
It was also the field in which we kept researching under the governmental outlines of the National Cancer Prevention and Control Programme (2004–10) (2). However, the population survival rate of cancers has not been dramatically improved, mainly because of the limited proportion of early diseases. Massive screening of cancers must be a great burden and challenge in China, currently for both organization and finance. Therefore, we recognized that the way to progress in cancer control is to identify, screen, and surveil the high-risk subpopulation in an organized and reasonable manner. The plan that outlines for a Healthy China 2030 was issued in 2016, with the expectation of 5-year nationwide survival of cancers improved by 15%, mainly based on this.
China is a multiethnicity country, along with differential conditions of public health and healthcare resources in the aspect of ethnicity and region. Therefore, under the vision of National Health for All, we aimed to investigate the risk factor of gastric cancer among Tibetans and suggest a tailored and strengthened prevention and screening protocol. As an example, our previous hospital-based cross-sectional study on cancer-free population found that the risk of H. pylori infection was significantly higher among Tibetan ethnicity than Han ethnicity (58.9% vs 40.8%, adjusted odds ratio = 2.10, 95% confidence interval 1.65–2.68) (3). Unpublished data of a meta-analysis also demonstrated the higher prevalence of H. pylori infection in Tibetans compared with Hans, especially higher in Tibet and Northwest China compared with the Sichuan province (4). Besides, the prevalence of H. pylori infection among gastric cancer Tibetans was up to 80.0% compared with 55.1% in gastric cancer Hans (5).
Therefore, our findings were consistent with the conclusion of birthplace as an important demographic factor for predicting gastric cancer risk. Moreover, the Tibetan ethnicity was susceptible to H. pylori infection, particularly in the less-developed regions. The potential explanation of higher H. pylori prevalence and gastric cancer risk would be different lifestyle and healthcare resources between ethnicities and regions. Our findings suggest promoting health education, organization and financial support in H. pylori screening and eradication among Tibetans, and endoscopic screening and surveillance among infected Tibetans under a precise and affordable budget.
CONFLICTS OF INTEREST
Guarantor of the article: Xin-Zu Chen, MD, PhD.
Specific author contributions: R.W.: for writing. R.W., D.B., and W.X.: for data and interpretation providing. X.-Z.C.: for academic inspection and proofreading.
Financial support: None to report.
Potential competing interests: None to report.
Sichuan Gastric Cancer Early Detection and Screening (SIGES) project.
1. Tan MC, Jamali T, Nguyen TH, et al. Race/ethnicity and birthplace as risk factors for gastric intestinal metaplasia in a multiethnic United States population. Am J Gastroenterol 2022;117:280–7.
2. Chen XZ, Liu Y, Wang R, et al. Improvement of cancer control in mainland China: Epidemiological profiles during the 2004–10 National Cancer Prevention and Control Program. Lancet 2016;388:S40.
3. Wang R, Zhang MG, Chen XZ, et al. Risk population of Helicobacter pylori infection among Han and Tibetan ethnicities in western China: A cross-sectional, longitudinal epidemiological study. Lancet 2016;388:S17.
4. Bai D, Wang AM, Liu K, et al. Prevalence difference of Helicobacter pylori infection between Tibetan and Han ethnics: The protocol of a meta-analysis on epidemiologic studies. Medicine (Baltimore) 2019;98:e18566.
5. Xiang W, Wang R, Bai D, et al. Helicobacter pylori related gastric cancer screening and cost-effectiveness analysis: A hospital-based cross-sectional study (SIGES). Nutr Cancer 2022. doi: 10.1080/01635581.2021.2022168