Carcinoma of the gastro-esophageal junction: are there two types of adenocarcinoma in this region?

Aims In order to assess the origin of cardia adenocarcinoma we evaluated its morphological and phenotypical (i.e. CK pattern) characteristics compared with Barrett’s adenocarcinoma and distal gastric adenocarcinoma. Methods We studied 35 adenocarcinoma of the cardia (Siewert type II) consecutively operated upon. As control groups we studied 14 long Barrett’s adenocarcinomas (Siewert type I) and 10 distal gastric cancers. All surgical specimens were immunostained for CK7/20. The immunohistochemical staining was considered as positive if 50% or more of the tumor cells were stained. Results Among the 35 cardia adenocarcinomas, 13 had gastric intestinal metaplasia (GIM) with detectable cardial intestinal metaplasia (CIM) in 9/13, while 22 were negative for GIM and CIM. Hp infection was detected in 30/35 cases (86%). The 35 type II adenocarcinomas showed a CK20+/CK7– expression pattern (i.e. ‘gastric pattern’) in 9; a CK20-/CK7+ expression (i.e. ‘Barrett’s pattern’) in 12; a CK20+/CK7+ expression (i.e. ‘mixed pattern’) in 14. 100% type II shows CKs immunostaining correlation among GIM/CIM and adenocarcinoma. All type I adenocarcinomas showed the CKs Barrett’s pattern both in the tumor and intestinal metaplasia, without GIM and Hp infection. Distal gastric cancers showed CKs gastric pattern in 6/10 and CKs mixed pattern in 4/10, both in tumor and intestinal metaplasia. Conclusions Cancer of the cardia seems to have more often a gastric-like than Barrett’s-like biomorphological features. This information supports the differentiation between type I and type II tumors, the first one caused by GERD, the second one by the same carcinogenetic processes of gastric cancer. Different surgical approaches to type I and type II adenocarcinomas seems to be appropriate. Further investigation is needed.