A 10-year Population-based Study of the Differences between NECs and Carcinomas of the Esophagus in Terms of Clinicopathology and Survival.

Purpose: The prevalence of esophageal NECs is rising, but to date, no studies have compared its clinicopathological characteristics to those of esophageal ACs and SCCs from the same period. Patients and methods: A 10-year population-based retrospective cohort study was conducted with the Surveillance, Epidemiology, and End Results Program database. Statistical analyses were performed using Intercooled Stata 12.0 software. Results: A total of 17,196 eligible patients with esophageal tumors, including 246 NECs, 6,102 SCCs and 10,848 ACs, were analyzed. ACs showed an obviously higher prevalence than the other two tumor types, and the prevalence of NECs was increasing. NECs were associated with an obviously worse survival than ACs (log-rank test, P<0.01). Most NECs were poorly differentiated and had an obviously higher percentage of metastasis. NECs and ACs often metastasized to the liver (29.41% and 23.11%, respectively), while SCCs typically metastasized to the lung (15.84%) and distant lymph nodes (15.37%). We divided the patients into two groups for further analysis according to the metastasis status. For NECs, no benefit was obtained by surgery in metastatic disease. For SCCs and ACs, surgery of the primary sites produced survival benefits in both groups, but the benefits of lymphadenectomy and metastasis dissection need further study. Conclusion: NECs of the esophagus have the worst prognosis compared to SCCs and ACs from the same period. Radical surgery provides limited benefits to patients diagnosed with NECs, so systemic treatments should be considered instead of surgical procedures. A unique guideline with a new staging and grading system for esophageal NECs is urgently needed.