Abstract P4-07-03: MicroRNAs correlating with outcome in patients treated with first-line bevacizumab for metastatic breast cancer

Background: Biomarkers predicting response to bevacizumab containing therapy in breast cancer are of urgent need. MiRNAs, small non-coding RNAs, can be involved in tumor evolution including regulation of angiogenesis and development of treatment resistance. Therefore, miRNAs can provide both prognostic and predictive information in different cancer entities. Patients and methods: A genome-wide miRNA profiling using high-throughput TaqMan® Array Human MicroRNA Cards enabling quantification of 754 unique human miRNAs was performed. Formalin-fixed paraffin-embedded specimens from 60 patients treated with bevacizumab as first-line therapy at our institution were analyzed. Based on the median overall progression-free survival (PFS) patients were divided into a responder (G1) and a non-responder group (G2). Differentially expressed miRNAs were selected considering a more than two-fold change and a false discovery rate (FDR) Results: Overall median PFS was 9.3 months with a median PFS of 17.5 and 5.0 months in G1 and G2, respectively. Eight miRNAs (miR-19b-3p, miR-21-5p, miR-9-5p, miR-590-5p, miR-106b-5p, miR-20a-5p) were significantly differentially expressed between these groups (FDR Conclusion: Twelve miRNAs in breast cancer tissue could be identified showing promising predictive value for bevacizumab-based therapy. Although these data need to be confirmed, differences in miRNA expression could help identifying patients with greater benefit from anti-VEGF agents. Citation Format: Simon P Gampenrieder, Frank Hamacher, Gabriel Rinnerthaler, Clemens Hufnagl, Hubert Hackl, Franz Romeder, Claudia Mus, Cornelia Hauser-Kronbeger, Brigitte Mlineritsch, Richard Greil. MicroRNAs correlating with outcome in patients treated with first-line bevacizumab for metastatic breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-07-03.