Effectiveness and safety of combined nimotuzumab and S-1 chemotherapy with concurrent radiotherapy for locally advanced esophageal cancer in malnourished and elderly patients: A prospective phase II study.

Objective: Definitive chemoradiotherapy (dCRT) is the standard treatment for unresectable locally advanced esophageal cancer. However, this treatment is associated with substantial toxicity, and most malnourished or elderly patients are unable to complete this therapy. Therefore, there is a need for a more suitable radiotherapy combination regimen for this population. This study was aimed to evaluate the efficacy and safety of a combination regimen comprising chemotherapy with nimotuzumab and S-1 and concurrent radiotherapy for patients with fragile locally advanced esophageal cancer with a high Nutritional Risk Screening 2002 (NRS-2002) score.

Methods: Eligible patients with unresectable esophageal carcinoma who had an NRS-2002 score of 2 or higher were enrolled. They were treated with S-1 and nimotuzumab with concurrent radiotherapy, followed by surgery or definitive radiotherapy. The primary endpoint was the locoregional control (LRC) rate.

Results: A total of 55 patients who met the study criteria were enrolled. After completion of treatment, surgery was performed in 15 patients and radiotherapy was continued in 40 patients. The median follow-up period was 33.3 [95% confidence interval (95% CI), 31.4-35.1)] months. The LRC rate was 77.2% (95% CI, 66.6%-89.4%) at 1 year in the entire population. The overall survival (OS) rate and event-free survival (EFS) rate were 57.5% and 51.5% at 3 years, respectively. Surgery was associated with better LRC [hazard ratio (HR)=0.16; 95% CI, 0.04-0.70; P=0.015], OS (HR=0.19; 95% CI, 0.04-0.80; P=0.024), and EFS (HR=0.25; 95% CI, 0.08-0.75; P=0.013). Most adverse events were of grade 1 or 2, and no severe adverse events occurred.

Conclusions: For malnourished or elderly patients with locally advanced esophageal cancer, radiotherapy combined with nimotuzumab and S-1 is effective and has a good safety profile.