The present invention relates to methods and compositions for determining whether a subject having prostate cancer is at greater risk of developing progressive disease, and methods of treating the subjects. It is based, at least in part, on the discovery that approximately 90% of men carrying at least one of the following fusion genes: TRMT11-GRIK2, SLC45A2-AMACR, MTOR-TP53BP1, LRRC59-FLJ60017, TMEM135-CCDC67 and CCNH-05orf30 experienced prostate cancer recurrence, metastases and/or prostate cancer-specific death after radical prostatectomy (each examples of “progressive prostate cancer”), while these outcomes occurred in only 36% of men not carrying any of these fusion genes. It is also based, at least in part, on the discovery that no patient studied survived five years without recurrence if their primary prostate cancer contained a TRMT11-GRIK2 or MTOR-TP53BP1 fusion gene. It is also based, at least in part, on the discovery that the protein encoded by the MAN2A1-FER fusion gene exhibits kinase activity.