Characterizing esophageal mixed neuroendocrine-non-neuroendocrine neoplasms: insights from a retrospective multicenter study of clinical outcomes and prognostic indicators.

BACKGROUND

The esophageal mixed neuroendocrine-non-neuroendocrine neoplasm (MiNEN) is an extremely rare but poor prognosis tumor.

OBJECTIVES

This retrospective study aimed to analyze the clinical characteristics of MiNEN and to investigate postoperative survival and prognostic factors.

DESIGN

This retrospective study analyzed 69 patients diagnosed with esophageal MiNEN at two major esophageal cancer centers in China from January 2000 to December 2021.

METHODS

We assessed demographic data, tumor characteristics, treatment modalities, and survival outcomes. Statistical analyses included Kaplan-Meier survival curves and Cox regression models to evaluate prognostic factors.

RESULTS

The most common histological types were combinations of small-cell carcinoma and squamous carcinoma (91.3%). The correct diagnostic rate of preoperative pathologic biopsy was only 4.3%. The median overall survival (OS) was 24.0 months, and disease-free survival (DFS) was 16.6 months. The 1-, 3-, and 5-year survival rates were 84.1%, 34.8%, and 25.3%, respectively. A peak period of recurrence or metastasis occurs in the first year after surgery, and regional lymph node recurrence is the main route of postoperative recurrence or metastasis. Tumor size, T-stage, N-stage, and tumor, lymph node, metastasis (TNM) stage were significant prognostic factors. Subgroup analyses showed that in patients with limited-stage MiNEN in stages I-III, the postoperative adjuvant treatment modality failed to improve OS and DFS compared with surgery alone. Postoperative adjuvant therapy also failed to prolong OS and DFS in patients with lymph node-positive MiNEN. No significant survival benefits were observed with different surgical techniques or adjuvant chemotherapy regimens.

CONCLUSION

Esophageal MiNEN has aggressive behavior and a poor prognosis. In China, the pathologic type of esophageal MiNEN may be dominated by a combination of small-cell carcinoma and squamous carcinoma. Early-stage disease significantly correlated with improved survival outcomes. Current treatment protocols, similar to those for other esophageal cancers, show limited efficacy in improving patient survival.