Clinical Effect of Radiotherapy Combined with Chemotherapy for Non-Surgical Treatment of the Esophageal Squamous Cell Carcinoma

BACKGROUND Chemoradiotherapy (CRT) is widely accepted and is considered a standard treatment, particularly for unresectable and inoperable esophageal squamous cell carcinoma (ESCC). However, the optimal use of the combined modalities of chemotherapy (CT) and radiotherapy (RT) remains controversial. In addition, no consensus has been reached regarding the exact efficacy of consolidation chemotherapy (CCT) and the most appropriate radiotherapy dose. MATERIAL AND METHODS Clinical data from 262 ESCC patients treated with CRT (n=165) or RT alone (n=97) were collected and reviewed. The long-term outcomes were analyzed, and treatment related acute toxicity reactions were compared. RESULTS The 1-year, 3-year, and 5-year overall survival (OS) rates were 75.3%, 35.6%, and 25.3%, respectively, for the CRT group and 61.5%, 26.7%, and 17.6% for the RT-alone group (P=0.015). The concurrent chemoradiotherapy (CCRT) and sequential chemoradiotherapy (SCRT) groups exhibited similar survival outcomes (for OS, P=0.568; for progression-free survival (PFS,) P=0.145). CCT after CCRT did not influence OS (P=0.236) but was associated with a more favorable PFS (P=0.020). In addition, high-dose of 60-65 Gy tended to prolong OS compared with low-dose (65 Gy). The incidence of adverse reactions, such as esophagitis and leukopenia, in the CRT group were significantly higher than in the RT-alone group (P=0.019, P=0.001, respectively), and no significant difference was observed between patients treated with CCRT and CCT after CCRT. CONCLUSIONS Treating non-surgical ESCC patients with CCRT conferred a significant survival benefit compared with RT alone. CCT after CCRT prolongs PFS but does not increase acute toxicity. High-dose (60-65 Gy) CCRT could generate more favorable survival outcomes.