PURPOSE/OBJECTIVE(S):The esophageal cancer ranked 7th in the morbidity of malignant cancer and the 6th contributed to carcinoma deaths. Most patients are diagnosed of advanced stage at first visiting. The 5-year survival rate of unresectable esophageal cancer is about 20% after the standard treatment of concurrent chemo-radiotherapy. Nimotuzumab, a humanized anti-EGFR antibody, has shown good efficacy and low toxicity in epithelial tumors. This two-center, real-world study evaluated the efficacy and safety of nimotuzumab combined with concurrent chemoradiotherapy in unresectable esophageal squamous cell carcinoma (ESCC).
MATERIALS/METHODS:Totally 503 eligible unresectable ESCC patients from Jan 2014 to Dec 2020 were included. 1:2 nearest neighbor propensity score matching (PSM) was performed to match the Nimo group (nimotuzumab plus concurrent chemo-radiotherapy) and CRT group (concurrent chemo-radiotherapy), and the covariates included age, gender, tumor location, lesion length, TNM stage, clinical stage, and radiotherapy dose. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective response rate (ORR), and disease control rate (DCR).
RESULTS:A total of 61 patients were in Nimo group which received nimotuzumab (200 mg/w, 4-6 weeks) combined with concurrent chemo-radiotherapy (chemotherapy: S-1/FP/TP/DP for 2-4 cycles; radiotherapy: 2DRT,3D-CRT or IMRT, 50-70 Gy in 25-35 fractions) and 107 patients in CRT group only received concurrent chemo-radiotherapy. The baseline characteristics were well balanced between the two groups. The efficacy of Nimo group was better than that of CRT group. The ORR was 85.2% vs. 71.0%, (P=0.037), the DCR was 98.4% vs. 91.6%, (P>0.05). The median PFS was 28.07 months vs. 19.54 months, and the 1-, 3- and 5-year PFS rates were 78.2% vs. 72.9%, 37.5% vs. 28.3%, and 29.1% vs. 21.3%, respectively (HR: 0.6860, 95% CI: 0.4902-0.9600, P=0.034). The median OS was 34.93 months vs. 24.30 months and the 1-, 3- and 5-year OS rates were 88.5% vs. 81.3%, 46.8% vs. 35.2% and 37.4% vs. 28.0%, respectively (HR: 0.6701, 95% CI: 0.4792-0.9372, P=0.024). The adverse events including radiation esophagitis, radiation pneumonitis, bone marrow suppression, nausea, vomiting, and rash were no significantly different between the two groups (P>0.05).
CONCLUSION:Nimotuzumab combined with concurrent chemo-radiotherapy improved the ORR, and prolonged PFS and OS in unresectable ESCC patients with a good tolerance.