Carcinosarcoma of the esophagus: A report of 6 cases associated with zinc finger E-box-binding homeobox 1 expression

Esophageal carcinosarcoma (ECS) has been suggested to result from an epithelial mesenchymal transition (EMT) phenomenon. However, knowledge on its underlying molecular features is limited. The clinical and pathological features, and the prognosis of ECS require further investigation. In the present study, a total of 325 patients with esophageal tumors were observed between January 2004 and December 2014, of which 6 patients were diagnosed pathologically with ECS. The clinicopathological features were compared with those of corresponding cases with the identical pathological T stage (pT) of esophageal squamous cell carcinoma (ESCC). In terms of the clinical T stage (cT), the 6 cases were composed of cT1, cT2, cT3 and cT4 in 1, 1, 3 and 1 case, respectively. Nevertheless, pT was eventually diagnosed as pT1 in all cases. There was a large discrepancy between clinically diagnosed depth of tumor invasion prior to surgery and depth of tumor invasion following surgery. Zinc finger E-box-binding homeobox 1 (ZEB1), an EMT-associated transcription factor, was expressed only in the sarcoma component in all 6 cases of ECS. The ECS cases had a significantly poorer prognosis compared with the 115 pT1 ESCC cases. The present study suggests that the depth of invasion of ECS lesions does not correspond with their respective size, and the EMT of the carcinoma component may affect the prognosis by overexpression of the ZEB1 gene.