Chemoradiotherapy is effective for primary esophageal adenosquamous cell carcinoma but ineffective for the metastatic adenocarcinoma component

Abstract

A 62-year-old man was referred to our hospital with dysphagia. Blood examination revealed significantly elevated serum CA19-9 levels but normal CEA and SCC levels. Imaging uncovered thoracic esophageal cancer with lung and bone metastasis, and subsequent endoscopic biopsy specimens of the primary esophageal tumor showed poorly differentiated squamous cell carcinoma. The patient underwent palliative chemoradiotherapy, but died due to progression of multiple metastases and increasing serum CA19-9 levels. Autopsy revealed adenocarcinoma in multiple metastatic foci, although the squamous component had disappeared in the primary and metastatic lesions. Therefore, we concluded that the adenocarcinoma component of adenosquamous cell carcinoma was refractory to chemoradiotherapy.