Endostatin and Oxaliplatin‐Based Chemoradiotherapy for Inoperable Esophageal Squamous Cell Carcinoma: Results of a Phase II Study

LESSONS LEARNED. Definitive concurrent chemoradiotherapy based on oxaliplatin and endostatin was effective with the objective response rate exceeding 80%, and the treatment‐related toxicities were acceptable. The treatment compliance of the current combination was much higher, without significant reduction in survival outcomes, than historical reports. BACKGROUND. This phase II trial aimed at assessing the efficiency and safety of definitive concurrent chemoradiotherapy (dCRT) using oxaliplatin (OHP) and endostatin in patients with inoperable esophageal squamous cell carcinoma (ESCC). METHODS. Radiotherapy was delivered with a daily fraction of 2.0 Gy to a total dose of 60.0 Gy over 6 weeks. Endostatin and OHP were both intravenously administered at doses of 7.5 mg/m(2) daily for 2 weeks and 135 mg/m(2) on day 1, respectively, every 3 weeks. The primary endpoint was the objective response rate (ORR). RESULTS. The analysis included 37 patients. The median age was 63 years (range: 49–71 years), and all patients were stage III–IVA. Of these patients, 97.3% (36/37) completed the dCRT course with an ORR of 83.8%, including 10 (27.0%) patients with complete response and 21 (56.8%) patients with partial response. The median overall survival (OS) time was 18.5 months (95% confidence interval [CI]: 10.6–26.4) with a 2‐year OS rate of 39.6% (95% CI: 0.202–0.590). The median progression‐free survival (PFS) time was 11.5 months (95% CI: 7.6–15.4) with a 2‐year PFS rate of 20.2% (95% CI: 0.049–0.355). Grade 3 toxicities included esophagitis (five patients) and leukocytopenia (three patients). Grade 4 leukopenia was observed in one patient. Late toxicity was infrequent, and no treatment‐related death occurred. Posttreatment dysphagia scores were significantly improved when compared with baseline (p < .001). CONCLUSION. dCRT based on OHP and endostatin resulted in high treatment compliance with manageable toxicities. This combination resulted in encouraging ORR without compromising survival outcomes. It should be validated in future clinical studies.