Forthcoming Step in Gastric Cancer Prevention: How Can Risk Stratification Be Combined with Endoscopic Screening for Gastric Cancer?

Abstract

Although the concern for gastric cancer prevention has increased, gastric cancer has remained a heavy burden worldwide and is not just a local issue in East Asian countries. However, as several screening programs (listed below) have shown some success, it is important to determine whether the situation is changing in some other countries and whether similar methods should be recommended. Endoscopic screening has been performed as a national program in South Korea and Japan, and the results have shown a reduction in gastric cancer mortality. Although the efficacy of Helicobacter pylori eradication has been established, the efficacy of the screen-and-treat strategy is presently being evaluated in randomized controlled trials. The serum pepsinogen test and endoscopic examination can divide high-risk subjects with severe gastric atrophy from average-risk subjects. Risk stratification is anticipated to contribute to an efficient method of prediction of gastric cancer development when combined with endoscopic screening. Countries with a high incidence rate should realize the immediate need to reduce gastric cancer death directly by endoscopic screening and should recognize screen-and-treat as a second option to reduce future risk. However, all forms of gastric cancer prevention programs have some harms and potential to increase unnecessary examinations. A balance of the benefits and harms should be always considered. Although further study is needed to obtain sufficient evidence for gastric cancer prevention, the best available method should be examined in the context of each country.

Keywords: Endoscopes; Helicobacter pylori antibodies; Mass screening; Serum pepsinogens; Stomach neoplasms.

Fig. 1

Maximizing real benefits of cancer screening. The benefit of cancer screening increases according to the increase of screening frequencies/intensities but becomes flattened beyond the optimal level. On the other hand, the harms directly increase according to the screening frequency. The real benefits lead to the difference between benefits and harms. To maximize the real benefits of screening, quality assurance and shared decision-making should be always considered. Increasing sensitivity and screening uptake lead to increased benefits until the optimal level is reached. Beyond this level, risk management, decrease in screening frequency and increase specificity could be helpful to reduce harms.

Fig. 2

Risk-stratified management for gastric cancer. The basic concept of risk-stratified management for gastric cancer is shown. The risk of gastric cancer is shown on the y-axis with intervention (management strategy) on the x-axis. Clinically relevant strata are shown from average risk to early cancer. On the population level, the risk of gastric cancer is basically low, and they are the main target population for cancer screening. However, gastric cancer screening is performed for subjects with various backgrounds. If the background risk is classified, the screening interval can be changed according to the background risk. Ideally, subjects with a high risk are screened at short intervals and subjects with low risk are screened at long intervals. However, the risk threshold of individuals for screening may vary between the healthcare systems and disease burden among countries. HP, Helicobacter pylori; ESD, endoscopic mucosal resection.