Comparison of concurrent chemoradiotherapy with radiotherapy alone for locally advanced esophageal squamous cell cancer in elderly patients: A randomized, multicenter, phase II clinical trial

This randomized, multicenter, phase II clinical trial was performed to compare the safety and efficacy of concurrent chemoradiotherapy using S-1 (CCRT) with radiotherapy alone (RT) for elderly patients with locally advanced esophageal squamous cell carcinoma (ESCC). All eligible patients were randomly assigned to the CCRT group or the RT group at a 1:1 ratio. The CCRT group received 50.4 Gy radiotherapy concurrent with S-1 and the RT group received 59.4 Gy radiotherapy alone. The primary endpoints were toxicity and the overall response rate (ORR), and the secondary endpoints were overall survival (OS) and progression-free survival (PFS). In total, 157 elderly patients with ESCC were recruited from December 2016 to March 2020. By June 2021, the median follow-up duration had reached 38 months. No grade 5 toxicities occurred in either group and the overall rate of severe toxicities (>= grade 3) was higher in the CCRT group (19.2% vs 7.6%; P = .037), particularly neutropenia (7.7% vs 1.3%; P = .06). The CCRT group presented a significantly higher ORR (83.3% vs 68.4%; P = .009) and prolonged PFS (25.7 vs 13.9 months; P = .026) than the RT group. The median OS was 27.3 months in the CCRT group and 19.1 months in the RT group (P = .59). For patients older than 70 years with locally advanced ESCC, concurrent chemoradiotherapy with S-1 had tolerable adverse effects and improved ORR and PFS compared to radiotherapy alone.