Chemoradiotherapy versus Chemotherapy Alone in Extensive-Stage Small Cell Esophageal Carcinoma: A Multicenter...

Small cell esophageal carcinoma (SCEC) is a rare and highly aggressive malignancy characterised by a poor prognosis, particularly in patients with extensive disease. The effectiveness of incorporating radiotherapy to chemotherapy remains ambiguous. This study aimed to evaluate the survival benefits of chemoradiotherapy (CRT) compared to chemotherapy (CT) alone in patients with extensive-stage small cell esophageal carcinoma (ES-SCEC).

In this multicenter, retrospective study, 191 ES-SCEC patients treated across 15 Chinese institutions between April 2002 and November 2021 were included. Patients were stratified into two groups: CT (n = 108) and CRT (n = 83). Propensity score matching (PSM) was employed to balance baseline characteristics. Kaplan-Meier analysis was conducted to assess overall survival (OS) and progression-free survival (PFS).

Among the 191 ES-SCEC patients (73.8% male), tumours were predominantly located in the lower thoracic esophagus (46.1%). Oligometastasis occurred more frequently in the CRT group (84.3% vs 69.4%). The majority of patients received etoposide-platinum chemotherapy (78%), whereas conventional radiation (50-66 Gy) was utilised in 97.2% of cases for CRT. In the overall cohort, median OS was 12.6 months. The 1-, 3-, and 5-year OS rates are 53.1% (95% CI: 46.4-60.9), 5.6% (95% CI: 2.8-11.1), and 3.0% (95% CI: 0.9-9.3), respectively. No significant difference between CRT and CT groups before (13.6 vs 11.5 months, P = .12) or after PSM (13.1 vs. 11.5 months, P = .25). However, T3-4N0-1M1 patients showed significantly improved OS (hazard ratio [HR = 0.47, 95% CI: 0.26-0.84, P = .011) and PFS (HR = 0.42, 95% CI: 0.23-0.77, P = .005) with CRT. CRT reduced locoregional recurrence (29.7% vs 58.2%) but increased grade ≥3 haematologic toxicity (leukopenia: 34.6% vs 15.4%). Multivariate analysis identified chemotherapy cycles (P < .01) and metastatic status (P = .002) as independent prognostic factors.

Compared to chemotherapy alone, chemoradiotherapy offers relatively minimal therapeutic benefit for ES-SCEC patients, while it exhibits significant efficacy in the T3-4N0-1M1 subgroup. Further research is necessary to develop more effective treatment strategies for SCEC.