Esophageal and gastric cardia cancers on 4238 Chinese patients residing in municipal and rural regions: A histopathological comparison during 24-year period

Background Nutrition deficiencies or poverty traditionally have been recognized to be related with increased risk for esophageal cancer (EC) in rural regions at junction of Henan, Hebei, and Shanxi provinces in northern China-the highest incidence area for esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA). Since the 1980s, economic and nutrition condition in these areas have been improved greatly. However, the histopathological types, staging pattern, and occurrence of ESCC and GCA, especially for esophageal adenocarcinoma (EAC), which have been rarely examined in the Chinese population during the past decades in these areas have not been well characterized to date. Methods Yearly diagnosed new esophageal cancer (ESCC and EAC) and GCA patients from Beijing Tongren Hospital (in municipal low-risk region) and Cixian People Hospital (in rural high-risk region) during 24-year period (1982-2005) were studied retrospectively. Only local resident patients with surgical resection were included. Age at diagnosis, tumor stage and site, and histopathological pattern were recorded for each patient from the tumor registry database in these hospitals. Results and Conclusions This study demonstrated that the common ESCC sites were different in municipal (chiefly in lower third of the esophagus) and in rural (chiefly in middle third of the esophagus) regions. The peak age of ESCC, EAC, and GCA patients in rural region was 10 years younger than in municipal region. Eighty-six percent of ESCC and 90% of GCA in municipal region were diagnosed at middle and advanced stage; similarly, more than 95% of ESCC and GCA in rural region were diagnosed at middle and advanced stage during the 24-year study period. An increasing tendency in number of yearly diagnosed new patients with ESCC and GCA was observed in municipal region, but not in rural region. However, an increasing tendency for EAC was observed both in municipal and rural regions during the past 24-year period. The present results demonstrate the difference in municipal and rural regions of ESCC, ECA, and GCA in histopathological types, and suggest that there may be different etiological factors involved in esophageal and gastric cardia carcinogenesis in these different areas.