Radiotherapy for small cell carcinoma of the esophagus: outcomes and prognostic factors from a retrospective study.

BACKGROUND: Small cell carcinoma of the esophagus (SCCE) is characterized by its progressive feature and poor prognosis. There is no consensus on a standard therapeutic modality for SCCE. In this study, we aimed to characterize the outcomes of primary SCCE patients treated by radiation therapy as part of treatment and investigate prognostic factors.

METHODS: We retrospectively analyzed the data of 42 SCCE patients who were treated by RT as part of treatment at the Sun Yat-sen University Cancer Center from 2001 to 2014. The Kaplan-Meier and log-rank method were used to analyze survival. Cox's hazard regression model was applied to determine prognostic factors.

RESULTS: Of the 42 enrolled patients, 25 had limited disease (LD) and 17 with extensive disease (ED). The overall response rate (CR + PR) was 60.0% (21/35). The median overall survival time (OS) for whole and LD group were 12.9 and 36.8 months. The 1-, 3- and 5-year OS rates of the whole cohort were 64.9, 31.3, and 13.9%, respectively. OS was significantly longer in patients with ECOG performance score (ECOG PS) < 2 (p = 0.001), lesion length ≤ 5 cm (p = 0.001), and LD (p = 0.049). In the patients with LD, multivariate analysis indicated that combined with chemotherapy (P = 0.046) and higher radiation dose (P = 0.027) predicted better prognosis in OS. The overall rate of grade 3-4 toxicities in the whole cohort was 37.5%. In total, 65% (17/26) patients with recurrent disease died with the metastasis with or without the primary recurrence.

CONCLUSION: RT was one of the effective and safe treatments for locoregional control of SCCE. Lower ECOG PS score, shorter lesion length, treated with chemotherapy, and a higher dose of RT were identified as favorable independent prognostic factors.