Molecular and clinical differences between adenocarcinomas of the esophagus and of the gastric cardia

Adenocarcinoma of the esophagus (ADCE) with Barrett's mucosa and adenocarci noma of the cardia (ADCC) are often reported as a single pathological entit y, In this study we have used strict anatomical-pathological criteria to di stinguish between these two lesions and we have investigated their differen ces in TP53 mutations, MDM2 gene amplification, and cytokeratin expression. DNA was extracted from the tumor areas of formalin-fixed, paraffin-embedde d sections in 26 ADCC and 28 ADCE patients. TP53 mutations were detected by temporal temperature gradient electrophoresis and identified by sequencing . MDM2 amplification was assessed by differential polymerase chain reaction . The expression of cytokeratins 4, 7, and 13 was examined by immunohistoch emistry. In ADCC, the male to female ratio was 1.8:1, compared to 27:1 in A DCE. Five ADCC patients had a history of other neoplasms, compared to only one ADCE patient. The two types of tumor differed in the prevalence of TP53 mutations (31% in ADCC and 50% in ADCE) and of MDM2 gene amplification (19 % in ADCC and 4% in ADCE), and in the pattern of expression of cytokeratin 7 (positive in 100% of ADCE and in 41% of ADCC) and cytokeratin 13 (positiv e in 81% of ADCE and in 36.5% of ADCC). ADCE and ADCC differ in their clini cal characteristics, in the prevalence of TP53 mutations and MDM2 amplifica tions, and in the patterns of cytokeratin expression. These results support the notion that ADCC and ADCE are distinct pathological entities.