IS BARRETTS-ESOPHAGUS THE PRECURSOR OF MOST ADENOCARCINOMAS OF THE ESOPHAGUS AND CARDIA - A BIOCHEMICAL-STUDY

Objective To obtain biochemical evidence that Barrett's esophagus (BE) is the precursor of most adenocarcinomas (Adc) of the esophagus and c ardia. Summary Background Data Based on morphologic data, BE was previ ously proposed as the precursor of most Ade of the esophagus. This hyp othesis would receive strong support if biochemical evidence were foun d to demonstrate a pattern common to BE and Adc of the esophagus and c ardia. Methods We studied the presence of intestinal-type proteins suc rase-isomaltase (SI) and crypt Cell Antigen (CCAg) in BE, Barrett's Ad c, and esophageal-cardial Adc without BE. In each case specimens were collected from normal esophagus, stomach, tumor, and BE mucosa when pr esent. To study related conditions, five specimens of peptic esophagit is and of squamous cell carcinoma were also analyzed. An indirect immu nofluorescence technique was employed and sections were analyzed with laser confocal microscopy imaging. Results Most Barrett's mucosa speci mens stained positively for SI (93%) and CCAg (89%). These proteins we re detected in BE independently of the type of metaplasia, the coexist ence of dysplasia, or the presence of associated Adc. SI and CCAg were present in 25 (96%) and 24 (92%) of the cases of Adc respectively. No statistical difference was detected in SI and CCAg expression between Adc samples with and without BE, between BE and Ade samples with or w ithout BE, and between tumors located in the esophagus Versus the card ia. No staining for these proteins was detected in stomach or esophage al mucosa, in submucosal glands of the esophagus, in peptic esophagiti s or squamous cell carcinoma. Conclusion These data show that BE and A dc of the esophagus and cardia have a similar phenotype and support th e hypothesis that most of these tumors probably originate from preexis ting BE.