Fifteen studies investigated whether genetic or epigenetic variations in the IGF-I (n = 5), IGF-II (n = 7), IGFBP-2 (n = 2) or IGFBP-3 (n = 3) gene were associated with prostate cancer risk or outcomes such as Gleason score, TNM stage, PSA recurrence or survival. This evidence concerns the gene IGF2 and Familial prostate cancer.