High miR-449b expression in prostate cancer is associated with biochemical recurrence after radical prostatectomy

BACKGROUND: Prostate cancer is one of the leading causes of cancer death amongst men in economically advanced countries. The disease is characterized by a greatly varying clinical course, where some patients harbor non- or slowly-progressive disease, others highly aggressive disease. There is a great lack of markers to differentiate between aggressive and indolent disease. Markers that could help to identify patients needing curative treatment while sparing those who do not. METHODS: MicroRNA profiling of 672 microRNAs using multiplex RT-qPCR was performed using 36 prostate cancer samples to evaluate the association of microRNAs and biochemical recurrence after radical prostatectomy. RESULTS: Among 31 microRNAs associated with recurrence, we identified miR-449b, which was further validated in an independent cohort of 163 radical prostatectomy patients. Patients expressing miR-449b had a significantly higher risk of recurrence (HR = 1.57; p = 0.028), and miR-449b was shown to be an independent predictor of recurrence after prostatectomy (HR = 1.9; p = 0.003) when modeled with known risk factors of recurrent disease in multivariate analysis. CONCLUSION: High miR-449b expression was shown to be an independent predictor of biochemical recurrence after radical prostatectomy.