Training and validation of a novel 4-miRNA ratio model (MiCaP) for prediction of postoperative outcome in prostate cancer patients

• Published in: Annals of oncology Vol. 29; no. 9; pp. 2003 - 2009
• Main Authors: Schmidt, L., Fredsøe, J., Kristensen, H., Strand, S.H., Rasmussen, A., Høyer, S., Borre, M., Mouritzen, P., Ørntoft, T., Sørensen, K.D.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-09-2018; Oxford University Press
• Subjects: Aged; biomarkers; Biomarkers, Tumor - genetics; Disease-Free Survival; Follow-Up Studies; Gene Expression Profiling; Humans; Kaplan-Meier Estimate; Male; microRNA; MicroRNAs - genetics; Middle Aged; Neoplasm Recurrence, Local - diagnosis; Neoplasm Recurrence, Local - genetics; Neoplasm Recurrence, Local - prevention & control; Original; Postoperative Period; Predictive Value of Tests; Preoperative Period; Prognosis; prostate cancer; Prostate-Specific Antigen - blood; Prostatectomy; Prostatic Neoplasms - genetics; Prostatic Neoplasms - mortality; Prostatic Neoplasms - surgery; Risk Factors; risk stratification; microRNA; prostate cancer; risk stratification; prognosis; biomarkers
• ISSN: 0923-7534; 1569-8041
• DOI: 10.1093/annonc/mdy243

New molecular biomarkers for prostate cancer (PC) prognosis are urgently needed. Ratio-based models are attractive, as they require no additional normalization. Here, we train and independently validate a novel 4-miRNA prognostic ratio model for PC.
By genome-wide miRNA expression profiling of PC tissue samples from 123 men who underwent radical prostatectomy (RP) (PCA123, training cohort), we identified six top candidate prognostic miRNAs and systematically tested their ability to predict postoperative biochemical recurrence (BCR). The best miRNA-based prognostic ratio model (MiCaP) was validated in two independent cohorts (PCA352 and PCA476) including >800 RP patients in total. Clinical end points were BCR and prostate cancer-specific survival (CSS). The prognostic potential of MiCaP was assessed by univariate and multivariate Cox-regression analyses and Kaplan–Meier analyses.
We identified a 4-miRNA ratio model, MiCaP (miR-23a-3p×miR-10b-5p)/(miR-133a×miR-374b-5p), that predicted time to BCR independently of routine clinicopathologic variables in the training cohort (PCA123) and was successfully validated in two independent RP cohorts. In addition, MiCaP was a significant predictor of CSS in univariate analysis [HR 3.35 (95% CI 1.34−8.35), P=0.0096] and in multivariate analysis [HR 2.43 (95% CI 1.45–4.07), P=0.0210]. As proof-of-principle, we also analyzed MiCaP in plasma samples from 111 RP patients. A high MiCaP score in plasma was significantly associated with BCR (P=0.0036, Kaplan–Meier analysis). Limitations include low mortality rates (CSS: 5.4%).
We identified a novel 4-miRNA ratio model (MiCaP) with significant independent prognostic value in three RP cohorts, indicating promising potential to improve PC risk stratification.