Discovery of microRNAs in tumor tissue predictive of time to progression and overall survival in patients with colorectal cancer treated with first-line capecitabine, oxaliplatin, and bevacizumab.

461 Background: The aim was to identify predictive and prognostic microRNAs (miRNAs) in cancer tissue samples from patients with metastatic colorectal cancer (mCRC) treated with 1.-line capecitabine, oxaliplatin, and bevacizumab (CapOxBev). Methods: Patients with mCRC treated with 1.-line CapOxBev were identified from 7 hospital databases and clinical and pathological data was extracted retrospectively. Formalin-fixed paraffin-embedded (FFPE) tissue samples from primary tumors were collected and RNA was purified from 3 x 10 µm sections, without micro-dissection. MiRNA expression was measured using TaqMan® Array Human MicroRNA A and B cards (Applied Biosystems) profiling 754 miRNAs. Raw miRNA expression values were checked for outliers and data was corrected using spike-in values. In a univariate selection method, each miRNA was related to time-to-progression (TTP) and overall survival (OS) using Cox proportional hazards model (threshold p < 0.001). Candidate miRNAs were tested using Akaike’s Information C...