Comparative outcomes of induction chemotherapy followed by definitive chemoradiotherapy versus chemoradiotherapy alone in esophageal squamous cell carcinoma

Purpose: To compare the clinical outcomes of induction chemotherapy (IC) followed by chemoradiotherapy (CRT) versus chemoradiotherapy alone in patients with locally advanced esophageal squamous cell carcinoma (ESCC). Patients and methods: Between 2002 and 2015, 267 ESCC patients who received definitive CRT with docetaxel and cisplatin were enrolled in this study. Through a matched case-control study, 85 patients receiving IC before CRT were matched 1:1 to patients who received CRT alone, according to age, gender, performance status, tumor location, tumor length, and pretreatment TNM stage. Results: The median overall survival (OS) in the IC group was significantly better than that in the CRT group (26.0 vs. 22.0 months), with 3-year OS rates of 30.6% vs. 25.9%, respectively (P = 0.028). However, IC plus CRT was associated with a significantly higher rate of grade 3-4 leukopenia than CRT alone (P = 0.048). The overall clinical response rate was 50.6% after IC in the IC group. The IC responder group showed significantly more favorable OS (P=0.002) and progression-free survival (P=0.001) compared with the IC non-responder group and the CRT group. Multivariate analysis revealed that age ≥ 60 (P = 0.003) and the addition of IC (P=0.016) were independent prognostic factors that affected survival positively. Conclusions: The addition of IC before CRT yielded satisfactory clinical outcomes and manageable toxicities. The combination of IC with CRT might be a promising treatment strategy to further improve systemic control and survival in ESCC. Prospective randomized trials are required to confirm the role of IC.