Total circulating microRNA level as an independent prognostic marker in breast cancer

Although breast cancer (BC) has a high survival rate, relapse events may occur which ultimately lead to aggressive disease. Circulating cell-free microRNAs (cf-miRNAs) are promising minimally invasive biomarkers with diagnostic and/or prognostic potential. A study at the German Cancer Research Center (Heidelberg) assessed total levels of cf-miRNAs in plasma samples of 250 BC patients. Baseline cf-miRNAs were prognostic for disease-free survival and overall survival. In a subset of 48 patients with serial plasma samples, levels of cf-miRNAs increased prior to clinical detection of progressive disease. The authors conclude that this is the first study to suggest that cf-miRNA level can be used as an independent prognostic marker in BC.