[Show abstract][Hide abstract] ABSTRACT: This study investigated cetuximab added to definitive concurrent chemoradiation for esophageal squamous cell carcinoma (ESCC). Previously untreated patients with stage II-IVa ESCC received cetuximab (400 mg/m(2) per week in week 1, then 250 mg/m(2) per week during weeks 2-8), paclitaxel (45 mg/m(2) per week) and cisplatin (20 mg/m(2) per week) in weeks 2-8 with 59.4 Gy radiotherapy. Epidermal growth factor receptor (EGFR) status in tumor specimens was assessed. Thirty-one patients were enrolled and evaluated for toxicity. Of the 29 patients assessable for a response, 20 (69.0%) had a clinical complete response (CR). Over a median follow up of 23.6 months, disease progression was observed in seven patients. The 1- and 2-year progression-free survival (PFS) rates were 85.5% and 75.1%, respectively. The PFS was shorter for patients with lymphatic metastatic disease than for those with locally confined tumor; the 1-year PFS rates were 78.7% and 92.3%, respectively (P = 0.038). Sixteen (55.2%) patients were immunohistochemically positive for EGFR. The patients with EGFR-expressing tumor had a CR rate of 75.0% compared with 61.5% in those with negative EGFR expression (P = 0.024). The PFS for patients with EGFR-expressing tumor was longer compared with the PFS of patients with negative EGFR (P = 0.133). The patients with prominent cetuximab-induced rash (≥grade 2) had a better CR rate and PFS than those with no or grade 1 rash (P < 0.05). The rates of grades 3/4 esophagitis, hematological and dermatological toxicities were 9.7%, 29.0% and 16.1%, respectively. The regimen of definitive chemoradiation plus cetuximab achieved good clinical response and has an acceptable safety profile in Chinese ESCC patients.