Updates on global epidemiology, risk and prognostic factors of gastric cancer

Abstract

Gastric cancer (GC) is defined as the primary epithelial malignancy derived from the stomach, and it is a complicated and heterogeneous disease with multiple risk factors. Despite its overall declining trend of incidence and mortality in various countries over the past few decades, GC remains the fifth most common malignancy and the fourth leading cause of cancer-related death globally. Although the global burden of GC has shown a significant downward trend, it remains severe in certain areas, such as Asia. GC ranks third in incidence and mortality among all cancer types in China, and it accounts for nearly 44.0% and 48.6% of new GC cases and GC-related deaths in the world, respectively. The regional differences in GC incidence and mortality are obvious, and annual new cases and deaths are increasing rapidly in some developing regions. Therefore, early preventive and screening strategies for GC are urgently needed. The clinical efficacies of conventional treatments for GC are limited, and the developing understanding of GC pathogenesis has increased the demand for new therapeutic regimens, including immune checkpoint inhibitors, cell immunotherapy and cancer vaccines. The present review describes the epidemiology of GC worldwide, especially in China, summarizes its risk and prognostic factors, and focuses on novel immunotherapies to develop therapeutic strategies for the management of GC patients.

Keywords: Epidemiology; Gastric cancer; Immunotherapy; Prognosis; Risk factors; Treatment.

Figure 1

The composition of incidences and mortalities of all cancer types in 2020 globally. A: The composition of incidences of all cancer types in 2020 globally; B: The composition of mortalities of all cancer types in 2020 globally. Bar plots show the composition of incidences or mortalities of all cancer types in both sexes, males and females, respectively. Citation: Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021; 71: 209-249. Copyright ©International Agency for Research on Cancer 2020. Published by International Agency for Research on Cancer[1].

Figure 2

Age-standardized incidence and mortality rates of gastric cancer in 2020 worldwide. A: Age-standardized incidence and mortality rates of gastric cancer (GC) in 2020 in the five continents; B: Age-standardized incidence and mortality rates of GC in countries classified by human development index in 2020 worldwide. ASIR: Age-standardized incidence rate (1/100000); ASMR: Age-standardized mortality rate (1/100000); HDI: Human development index. Citation: Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021; 71: 209-249. Copyright ©International Agency for Research on Cancer 2020. Published by International Agency for Research on Cancer[1].

Figure 3

Estimated age-standardized incidence and mortality rates of gastric cancer in 2020 in Asian countries. A: Estimated age-standardized incidence rates of gastric cancer (GC) in 2020 in Asian countries; B: Estimated age-standardized incidence rates of GC in males in 2020 in Asian countries; C: Estimated age-standardized incidence rates of GC in females in 2020 in Asian countries; D: Estimated age-standardized mortality rates of GC in 2020 in Asian countries; E: Estimated age-standardized mortality rates of GC in males in 2020 in Asian countries; F: Estimated age-standardized mortality rates of GC in females in 2020 in Asian countries. ASIR: Age-standardized incidence rate (1/100000); ASMR: Age-standardized mortality rate (1/100000). Citation: Sung H, Ferlay J, Siegel RL, Laversanne M, Soerjomataram I, Jemal A, Bray F. Global Cancer Statistics 2020: GLOBOCAN Estimates of Incidence and Mortality Worldwide for 36 Cancers in 185 Countries. CA Cancer J Clin 2021; 71: 209-249. Copyright ©International Agency for Research on Cancer 2020. Published by International Agency for Research on Cancer[1].

Figure 4

Trends in age-standardized incidence and mortality rates of gastric cancer according to the National Central Cancer Registry of China in 2012-2016[22-26]. A: Trends in age-standardized incidence rates of gastric cancer (GC) according to the National Central Cancer Registry (NCCR) of China in 2012-2016; B: Trends in age-standardized mortality rates of GC according to the NCCR of China in 2012-2016.

Figure 5

Summarization of risk factors of gastric cancer. H. pylori: Helicobacter pylori.