Neuroendocrine carcinoma of the esophagus: clinicopathologic study of 10 cases and verification of the diagnostic utility of mASH1, NeuroD1, and PGP9.5

Clinical characteristics, prognostic factors, and survival trends in esophageal neuroendocrine carcinomas: A population-based study

BACKGROUND

Esophageal neuroendocrine carcinoma (ENEC) is an extremely rare type of malignancy. Clinical data of ENEC are limited to case reports and case series. More information is needed on its clinical feature, management, and prognosis.

METHODS

This study collected information of ENEC patients diagnosed pathologically from 2010 to 2018. Data including demographic information, clinical features, and survival trends were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Statistical analyses were performed with STATA/SE 15.1, SPSS 25.0, and GraphPad Prism 8.

RESULTS

A total of 283 ENEC patients were included in this study. The small-cell and large-cell subtypes of ENEC possess similar clinical features. The lower third of the esophagus (58%) was the most common location of ENEC. At the time of diagnosis, most ENEC patients were AJCC 7th stage IV (48.1%). Metastasis occurred in more than half of the ENEC patients (53.4%), and the most common metastatic site was the liver (37.1%). Compared with poorly differentiated esophageal squamous cell carcinoma (ESCC), another aggressive malignancy of the esophagus sometimes confused with ENEC because of similar histological features, our study showed differences in tumor location and metastatic rate, but similar poor survival rates. Multivariate survival analysis showed that ENEC located at the middle third of esophagus (p = 0.013), "Brain metastasis" (p = 0.019), and "Liver metastasis" (p < 0.001) were independent predictors of worse outcomes. "Surgery" (p = 0.003), and "Chemotherapy" (p < 0.001) were associated with better survival.

CONCLUSION

A significant proportion of patients with newly diagnosed ENEC presented with metastatic disease. Predictors of poor survival included tumor location, brain metastasis, and liver metastasis. ENEC and poorly differentiated ESCC share certain histological features, but differ in tumor location and metastatic rate. Yet, no standard treatment strategy has been established, but surgery and chemotherapy were related to better outcomes.

SOX2 and Rb1 in esophageal small-cell carcinoma: their possible involvement in pathogenesis

Clinicopathological features and pathogenesis of esophageal small-cell carcinoma remain unclear. We hypothesized common cellular origin and pathogenesis in small-cell carcinoma of esophagus and lung associated with SOX2 overexpression and loss of Rb1. Expression of squamous-basal markers (CK5/6 and p40), glandular markers (CK18 and CEA), SOX2, and Rb1 were evaluated in 15 esophageal small-cell carcinomas, 46 poorly differentiated squamous cell carcinomas, and 88 small-cell lung carcinoma, as well as 16 embryonic esophagus. Esophageal small-cell carcinoma expressed higher levels of glandular markers and lower levels of squamous-basal markers than poorly differentiated squamous cell carcinoma. No significant differences were observed in immunohistochemistry profiles between small-cell carcinoma of the esophagus and the lung. SOX2 expression was high in esophageal small-cell carcinoma (70%±33% of nuclei), small-cell lung carcinoma (70%±26%), and the embryonic esophagus (75%±4%), and it was significantly lower in poorly differentiated squamous cell carcinoma (29%±28%). Rb1 expression was significantly lower in esophageal small-cell carcinoma (0.3%±1%), small-cell lung carcinoma (2%±6%), and the embryonic esophagus (7%±5%), and it was significantly higher in poorly differentiated squamous cell carcinoma (51%±24%). The immunohistochemistry profiles of small-cell carcinoma of the esophagus and the lung are highly similar. The loss of Rb1 function is a key contributor to the pathogenesis of both neoplasms. In addition, SOX2 overexpression observed in esophageal and lung small-cell carcinoma as well as in the embryonic esophagus indicated that esophageal small-cell carcinoma may arise from embryonic-like stem cells in the esophageal epithelium. The two distinct differentiation patterns (neuroendocrine and glandular) of esophageal small-cell carcinoma further support the fact that SOX2 has a pivotal role in the differentiation of pluripotent stem cells into esophageal small-cell carcinoma cells.