Autophagy-related proteins LC3 and Beclin-1 impact the efficacy of chemoradiation on esophageal squamous cell carcinoma.

Autophagy is a bulk protein and organelle degradation process essential for cellular maintenance, cell viability and development. This study investigated the prognostic role of LC3 and Beclin-1, two autophagy-related proteins, in patients with locally advanced esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiation. The data of 150 patients with stages II-IVa ESCC who had undergone definitive concurrent chemoradiation were studied; LC3 and Beclin-1 protein expression was evaluated by immunohistochemistry and western blot. The correlations between LC3 and Beclin-1 expression, the patients' clinicopathological features, and overall survival were analyzed. Eighty-three patients showed positive LC3 and 84 showed positive Beclin-1 protein expressions, but LC3 and Beclin-1 expression in ESCC was not significantly correlated (P=0.746). LC3 and Beclin-1 expression did not show any association with gender, age, tumor location, and treatment response. The median survival of patients with positive LC3 expression was 23.6 months, while the median survival was 32.0 months in patients with negative LC3 expression (P=0.049). The patients with LC3 and Beclin-1-positive tumors presented much poorer long-term survival. Multivariate analysis showed that clinical stage (P=0.019), treatment response (P=0.002), and LC3 expression level (P=0.021) were independent predictive factors of overall survival in patients with locally advanced ESCC receiving definitive chemoradiation. Patients with LC3 and Beclin-1-negative expression had a better overall survival than those with LC3 and Beclin-1-positive tumors. LC3 expression is an independent prognostic factor for overall survival in ESCC patients treated with definitive chemoradiation.