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Primary small cell carcinoma of esophageal (PSCCE) is a rare malignancy with aggressive behavior associated with a perceived poor prognosis. Due to its rarity, the clinical characteristics and the optimal clinical management have not yet been defined, therefore, we designed a multicenter retrospective study to analyze the prognostic factors and the impact of treatment on the prognosis of PSCCE patients. We retrospectively evaluated 704 consecutive patients with PSCCE from five participating centers between April 2008 and July 2021. The PSCCE was diagnosed based on the World Health Organization classification. Treatment strategies included surgery, radiotherapy (RT), or chemotherapy only, and combination of 2-3 treatment modalities (surgery, RT and chemotherapy). The estimated hazard rates provide the trajectory of progression and death overtime. Univariate survival analysis was conducted by using Kaplan-Meier plots, and the log-rank test was used to compare survival differences. Cox regression analysis was used to determine the independent prognostic factors in multivariate analysis. Overall, 69.0% (486/704) of the patients were male, with a median age of 63 years (range 38-96). Most of the patients were regional lymph node positive (N+, 64.0%), and nearly half with advanced stage (M+, 47.2%). With a median follow-up time of 16 months, 472 patients (67.0%) exhibited disease progression and 429 patients (60.9%) died. Following initial treatment, 85.1% (402/472) of progression/death and 80.1% (344/429) of mortalities occurred within 24 months. Consistently, the maximum annual death and progression/death hazards are highest in the 15.6 months and 9.6 months. The overall survival (OS) rates at 1, 3 and 5 years for all patients were 65.1%, 26.5% and 18.3%, respectively. Univariate survival analysis showed that ECOG score, alcohol abuse, TNM stage, N stage, and M stage were correlated with OS (P <0.05). Multivariate analysis showed that the N stage (HR: 1.378, P = 0.018) and M stage (HR: 1.945, P <0.001) carried independent prognostic factors for OS. In the term of treatment, the OS rates for M- patients treated with combined modality therapy (CMT, surgery±radiotherapy/chemotherapy) were better than those treated with surgery alone or radiotherapy/chemotherapy (3-year OS: 36.7% VS 25.6% VS 32.2%; P = 0.045). The OS rates for M+ patients treated with chemotherapy alone, radiotherapy alone, or radiotherapy combined with chemotherapy were no significant differences (3-year OS: 12.2% VS 19.4% VS 11.1%; P = 0.400). PSCCE is characterized by a high degree of malignancy with high risks of lymphatic and distant metastasis, N and M stages are the most important prognostic factor. In terms of treatment, comprehensive treatment is most likely to benefit patients without distant metastasis. [ABSTRACT FROM AUTHOR]