Can miRNA profiling allow us to determine which patients with esophageal cancer will respond to chemoradiotherapy?

Evaluation of: Ko MA, Zehong G, Virtanen C et al. miRNA expression profiling of esophageal cancer before and after induction chemoradiotherapy. Ann. Thorac. Surg. 94(4), 1094-1103 (2012). Most patients undergoing surgery for esophageal cancer are treated before surgery with chemotherapy and radiotherapy. However, some tumors respond poorly to these treatments. The article under evaluation profiled miRNA levels in esophageal cancers from patients who did respond to chemoradiotherapy versus those who did not. A large number of miRNAs were differentially expressed between responders versus nonresponders, and patients with either decreased miR-135b or increased miR-145 expression in cancer tissue had improved disease-free survival. Although this study has several limitations, including a mixed cohort of patients with adenocarcinoma and squamous cell carcinoma, and the absence of a validation set of patients, the results do suggest that a miRNA profiling approach may be able to circumvent one of the primary challenges for biomarker development, molecular heterogeneity.