Time trends in the incidence of esophageal adenocarcinoma, gastric adenocarcinoma, and superficial esophagogastric junction adenocarcinoma.

BACKGROUND: In Japan, the incidence of esophageal adenocarcinoma (EAC) and esophagogastric junction (EGJ) adenocarcinoma is expected to increase and that of gastric adenocarcinoma (GAC) is expected to decrease due to Westernization of the diet and the decreasing prevalence of Helicobacter pylori infection. However, few reports about these trends have included the latest data, and no reports about the time trend in the incidence of EGJ adenocarcinoma have focused on the etiologies (gastric cardia adenocarcinoma or EAC, including Barrett's adenocarcinoma). We therefore investigated the time trends in the incidence of these cancers by including the latest data.

METHODS: First, we investigated the time trends in EAC and GAC using population-based cancer registry data in Osaka Prefecture (1985-2014). We then investigated the time trend in superficial EGJ adenocarcinoma with clinicopathological features at Osaka International Cancer Institute (2006-2017).

RESULTS: From 1985 to 2014 in Osaka Prefecture, the incidence of EAC gradually increased in both sexes, while that of GAC in men did not significantly change and that in women decreased. The ratio of the EAC/GAC incidence increased 3.5 times in men and 1.8 times in women. In the secondary time trend survey for EGJ adenocarcinoma, the numbers of patients with endoscopic Barrett's esophagus and those without gastric mucosal atrophy increased, and the number of patients with lesions located above the EGJ line and histologically diagnosed as Barrett's adenocarcinoma increased.

CONCLUSIONS: The incidence of EAC and superficial EGJ adenocarcinoma with characteristics similar to those of EAC, including Barrett's adenocarcinoma, might be increasing.