Background and purpose: Distant metastasis (DM) after definitive chemoradiotherapy has not been a focus of research in esophageal carcinoma. At present, local-regional control is improving following advances in salvage treatments after definitive chemoradiotherapy. There is a need to focus on suppressing the development of DM. The aim of this study was to identify pre-treatment factors associated with DM after definitive chemoradiotherapy.
Materials and methods: This study included 144 patients with thoracic esophageal squamous cell carcinoma (Stage I/II/III/IV; 35/17/69/23) (TNM 7th) who underwent definitive chemoradiotherapy; >50 Gy was prescribed to all gross tumors with concurrent administration of 5-fluorouracil ± platinum. Pre-treatment factors included age, gender, performance status, tumor location, T/N/M status, tumor length, size of metastatic lymph nodes (LN size), and the presence of intramural metastasis or multiple primary tumors. The effects of pre-treatment factors on overall survival (OS) and DM were evaluated.
Results: The median follow-up period was 48 months. DM occurred as an initial progression in 21 % of patients, and LN size correlated with DM development (hazard ratio [HR] = 5.12; p = 0.0013) and poor OS (HR = 2.20; p = 0.0076) in univariate and multivariate analyses.
Conclusions: LN size is a quantitative pre-treatment prognostic factor that should be assessed prior to definitive chemoradiotherapy. Patients with large metastatic lymph nodes are at high risk of DM and should be monitored.
Keywords: Chemoradiotherapy; Esophageal carcinoma; Prognostic factor.