Dose-response relationship between radiation dose and loco-regional control in patients with stage II-III esophageal cancer treated with definitive chemoradiotherapy

Abstract

Purpose: The correlation between radiation dose and loco-regional control (LRC) was evaluated in patients with stage II–III esophageal cancer treated with definitive concurrent chemoradiotherapy (CRT). Materials and Methods: Medical records of 236 stage II–III esophageal cancer patients treated with definitive CRT at Yonsei Cancer Center between 1994 and 2013 were retrospectively reviewed. Among these, 120 received a radiation dose of <60 Gy (standard-dose group), while 116 received ≥60 Gy (high-dose group). The median doses of radiation in the standard- and high-dose groups were 50.4 and 63 Gy, respectively. Concurrent 5-fluorouracil/cisplatin chemotherapy was administered to most patients. 2 Results: There were no differences in patient characteristics between the two groups except for high Karnofsky performance status and lower-thoracic lesions being more prevalent in the standard-dose group. The median progression-free survival (PFS) and overall survival (OS) times were 13.2 and 26.2 months, respectively. Patients in the high-dose group had significantly better 2-year LRC (69.1% vs. 50.3%, P = 0.002), median PFS (16.7 vs. 11.7 months, P = 0.029), and median OS (35.1 vs. 22.3 months, P = 0.043). Additionally, LRC exhibited a dose-response relationship and the complete response rate was significantly higher in the high-dose group (P = 0.006). There were no significant differences in treatment-related toxicities between the groups. Conclusion: A higher radiation dose (>60 Gy) is associated with increased LRC, PFS, and OS in patients with stage II–III esophageal cancer treated with definitive CRT.