Systematic review of microRNAs as biomarkers and radiosensitivity modifiers in TNBC

Radiation therapy (RT) for triple-negative breast cancer (TNBC) treatment is currently delivered in the adjuvant setting and is under investigation as a booster of neoadjuvant treatments. However, TNBC radioresistance remains an obstacle, so new biomarkers are needed to select patients for any integration of RT in the TNBC therapy sequence. MicroRNAs (miRNAs) are important regulators of gene expression, involved in cancer response to ionizing radiation, and assessable by tumor tissue or liquid biopsy. Systematic review of the literature evaluated relationships between miRNAs and response to radiation in TNBC. Thirty-five miRNAs were identified to be TNBC related. Expression modulation of many of these miRNAs was radiosensitizing in experimental models. miRNA-21, -33a,-139-5p, and -210 were associated with TNBC patient outcome after RT. The authors conclude that dynamic assessment of circulating miRNAs could improve monitoring and TNBC RT efficacy, which is of particular interest in the neoadjuvant and the high-risk patients’ settings.