Clinical characteristics and associated factors of Japanese patients with adenocarcinoma of the esophagogastric junction: a multicenter clinicoepidemiological study.

Gastroesophageal reflux disease-related diseases, such as Barrett's esophagus and adenocarcinoma of the esophagogastric junction (AEGJ), are believed to occur less frequently in Asia than in Western countries. However, the number of reported cases is increasing, yet little is known regarding the epidemiology of AEGJ in Japan. The primary study aim is to investigate the clinicoepidemiological characteristics of AEGJ. The secondary aim is to identify factors associated with it. In the 6.5 years between January 2008 and June 2014, we reviewed 88,199 esophagogastroduodenoscopy (EGD) reports and associated medical records (Study 1). We conducted a case-control study to identify factors associated with AEGJ (Study 2). Control subjects were randomly selected and age and sex matched from among subjects who underwent EGD during medical evaluations. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using an unconditional logistic regression method. During the study period, 83 patients with AEGJ (72 men and 11 women; mean age 68 years) were diagnosed. Six cases were Siewert type I and 77 were type II. The incidence rate of AEGJ was 0.6-1.7/100,000 person-years. Compared with the 101 control subjects, obesity (body mass index ≧ 25 kg/m2; [OR = 2.82; 95% CI: 1.13-7.01]) was associated with AEGJ. The incidence rate of AEGJ is lower in Japan than in Western countries, but associated factors similar to those in Western patients were detected, including obesity, a hiatal hernia, smoking, and the male sex.