Changing trends in the proportion of adenocarcinoma of the esophagogastric junction in a large tertiary referral center in Japan

Abstract Introduction: A dramatic increase in incidence of adenocarcinoma of the esophagogastric junction (EGJ) over the past two decades has been reported in the West. However, epidemiological data from Asian countries have not shown a similar trend. The aim of this study was to determine the incidence of adenocarcinoma of the EGJ in a cohort of consecutive patients operated on for gastric adenocarcinoma at a major cancer referral center in Japan. Method: We reviewed pathological reports of all patients who underwent surgery for advanced gastric adenocarcinoma between 1962 and 2005 at the National Cancer Centre Hospital in Tokyo. Adenocarcinoma of the EGJ was defined from images recorded for each patient, in accordance with the classification of Siewert and Stein. The proportion of adenocarcinoma at the EGJ among operated gastric adenocarcinoma patients was compiled at five‐year intervals and serial comparison made. Results: A total of 6953 patients with advanced gastric adenocarcinoma were operated on; adenocarcinoma of EGJ was found in 520 patients. The overall proportion of adenocarcinoma of the EGJ increased from 2.3% (1962–1965) to 10.0% (2001–2005). The proportion of Siewert Type II rose from 28.5% (1962–1965) to 57.3% (2001–2005), while that of Type I remained at around 1%. Conclusion: An increasing trend of adenocarcinoma of EGJ is observed in this study of patients operated on for gastric adenocarcinoma from 1962 to 2005 in a large tertiary referral center in Japan.