Retrospective Study of Clinicopathologic Features and Prognosis of High-grade Neuroendocrine Carcinoma of the Esophagus

Clinicopathologic features of esophageal neuroendocrine carcinoma (NEC), apart from those of small-cell carcinoma, have not been characterized. We evaluated the clinicopathologic features and prognosis including overall survival of NEC of the esophagus. We identified 40 patients with esophageal NEC from our institutional database. All cancers had been clinically staged using endoscopic ultrasonography, computed tomography, and positron emission tomography. Neuroendocrine differentiation was confirmed by immunohistochemical staining. The NEC component was classified into small-cell and large-cell subtypes, and non-neuroendocrine components were evaluated. Patients with locoregional disease were treated with chemoradiation with or without surgery or with surgery only. Patients with distant metastasis were treated with systemic therapy. The extent of residual tumors was evaluated in esophagectomy specimens after preoperative chemoradiation. Twenty-seven patients had large-cell NEC, and 13 had small-cell neuroendocrine carcinoma. An adenocarcinoma component was present in 15 patients and squamous carcinoma component in 1 patient. Synaptophysin was positive in all cases, and chromogranin was positive in 31 cases. Seventeen patients had distant metastasis, and 21 had locoregional disease. Seventeen patients with locoregional disease received preoperative chemoradiation. Disease progressed in 7 patients, and 10 had residual tumor in resection specimens. Overall survival was better with locoregional disease than with distant metastasis (P=0.006). Overall survival was better in patients with non-neuroendocrine component than in patients with pure NEC (P=0.031). There was no difference in prognosis between patients with large-cell NEC and those with small-cell neuroendocrine carcinoma. Esophageal NEC is an aggressive tumor, and patients with mix NEC have better outcome.