Urinary exosomal microRNAs as potential non-invasive biomarkers in breast cancer detection

Breast cancer (BC) is the most frequent malignant disease in women worldwide and the leading cause of cancer associated death as well. As especially advanced stages are challenging for the healthcare system, early BC detection is crucial striving for improved overall outcome and disease management. Established screening procedures show limited success in the early diagnosis of the disease and inherit several limitations. Aiming at a faster, easier and non-invasive BC screening, liquid biopsy biomarkers bear great potential to complete the current state-of-the-art diagnostics. This study explores the diagnostic potential of BC specific urinary microRNAs as a potential non-invasive BC screening method. Based on a case-control-study (69 BC patients vs. 40 healthy controls), expression level quantification and subsequent biostatistical computation of thirteen urine-derived microRNAs was performed to evaluate their diagnostic relevance in BC. Multilateral statistical assessment determined and repeatedly confirmed a specific panel of four urinary microRNAs (miR-424/miR-423/mir-660/let7-i) as highly specific combinatory biomarker tool. Herewith, it is possible to discriminate BC patients from healthy controls with 98.6 % sensitivity and 100 % specificity. Smaller feasibility studies have proven this method as highly potent already years ago. The given study finally provides large scale observations, sufficient statistic analysis, more refined methods and highly satisfying sensitivity and specificity. Therefore, it serves the implementation of urinary BC detection in the routine screening and offers a promising non-invasive alternative.