Plasma microRNAs to predict the response of radiotherapy in esophageal squamous cell carcinoma patients.

Although microRNAs (miRNAs) play an important role in esophageal squamous cell carcinoma (ESCC), their roles in radiotherapy response remain unexplored. Our study aims to investigate whether plasma miRNAs can be used as predictors of radiotherapy outcome in ESCC patients. We selected nine miRNAs, which were reported to be associated with carcinogenesis or radiobiology of ESCC, as the targets of our study. Plasma miRNA expression was investigated with 24 subjects (pre-, at the first week and post-radiotherapy). Tumor radiographic response and 3-year overall survival were used to evaluate the response. The results showed that the level of miR-16 in the patients with good outcome was significantly higher than that in the patients with poor outcome (P < 0.05, AUC: 0.762) at the post-radiotherapy. We also found that the variation tendency of miRNA expression were related to its radiotherapy response. Moreover, miR-16 levels increased by more than 2-fold following treatment, which were shown to be associated with longer OS (log-rank P = 0.009). In conclusion, miR-16 has considerable clinical value in predicting radiotherapy outcomes for ESCC patients.