Epidemiology of Barrett's Neoplasia in Japan.

[BACKGROUND] With a 50-year delay compared to Europe and the USA, esophageal adenocarcinoma (EAC) began to increase in Japan around 2010, and it is expected to continue rising over the next few decades. This 50-year discrepancy is primarily attributable to variations in the timing of the decline in Helicobacter pylori infection rates across the two regions, with the extent of obesity in Japan also exerting an influence on the projected increase in EAC. Currently, the incidence of EAC in Japan is approximately one-tenth to one-twentieth that observed in Europe and the USA. However, ongoing monitoring is essential to assess the potential for escalation of this cancer. Accurate estimation of the incidence of EAC in Barrett's esophagus (BE), a precancerous condition of EAC, is imperative for the establishment of appropriate endoscopic surveillance for early cancer detection.

[SUMMARY] The incidence of EAC in BE is largely determined by its length. In the Japanese population, BE with a length greater than 3 centimeters exhibits a high incidence of EAC and necessitates surveillance, while BE with a length less than 1 centimeter exhibits an exceptionally low incidence of EAC and is considered to require no surveillance. The challenge lies in determining the optimal approach for addressing BE with a length of 1-3 cm, which is observed in 5-15 percent of endoscopic examinees, necessitating careful consideration due to its significance.

[KEY MESSAGE] Since the EAC risk of BE varies greatly depending on its length, the need for surveillance and inspection intervals for BE in Japan should be defined by its length.