Extensive-stage small cell esophageal carcinoma: a retrospective analysis of treatment modalities

This study aimed to investigate the clinicopathological features, treatment strategies and outcomes, failure patterns, and prognostic factors impacting progression-free survival (PFS) and overall survival (OS) in patients with extensive-stage primary small cell esophageal carcinoma (ES-SCEC).

This retrospective study included consecutive patients with ES-SCEC diagnosed and treated at Fudan University Shanghai Cancer Center from January 2006 to December 2024. Clinicopathological data related to diagnosis, staging, and follow-up were collected. In patients with available tumor specimens, immunohistochemistry (IHC) was performed to assess the expression of POU2F3 (POU class 2 homeobox 3), standard neuroendocrine markers, thyroid transcription factor-1 and Ki-67. Univariate and multivariate Cox proportional hazards models were used to identify prognostic factors, with statistical significance defined as a two-sided p value < 0.05.

Among the 112 patients with ES-SCEC, the median PFS was 5.0 months (95% CI: 4.4-5.6), and the median OS was 9.0 months (95% CI: 7.9-10.1). Liver metastasis was the most common metastatic site at initial diagnosis (58.9%). The use of immune checkpoint inhibitors (ICIs), the number of chemotherapy (CT) cycle and T stage were identified as independent prognostic factors for OS. Independent predictors of PFS included T stage, CT cycle, and thoracic radiotherapy (TRT). The overall response rate (RR) was 52.7%, and the disease control rate (DCR) was 90.2%. Patients receiving CT combined with ICIs (n = 33) achieved significantly longer median OS than those who not treated with ICIs (n = 72) (13.8 months vs. 8.8 months, p = 0.029). Patients treated with TRT (n = 36) demonstrated improved local control and longer median PFS compared with those not receiving TRT (n = 69) (7.9 months vs. 4.1 months, p < 0.001). The combination of CT, ICIs, and TRT was associated with favorable outcomes, with median PFS and OS of 10.1 and 16.9 months, respectively.

The addition of ICIs to CT may be associated with improved survival in patients with ES-SCEC. This findings warrant validation in larger cohorts and prospective randomized studies.