Molecular profiling of ETS gene rearrangements in patients with prostate cancer registered in REDEEM clinical trial

Of the 146 patients, 99 (67.8%) (placebo, 51; dutasteride, 48) samples displayed the following Gleason patterns: 3+3 = 6 in 80 (54.8%) (placebo, 39; dutasteride, 41), 3+4 = 7 in 18 (12.3%) (placebo, 11; dutasteride, 7), and 4+4 = 8 in 1(0.68%) (placebo, 1). The remaining 47 samples showed atypical glands in 5 (3.4%) (placebo, 2; dutasteride, 3), HGPIN in 9 (6.1%) (placebo, 5; dutasteride, 4), and benign in 33 (22.6%) (placebo, 15; dutasteride, 18). Immunohistochemistry findings were positive for ERG and SPINK1 in 56 (56%) (placebo, 31; dutasteride, 25) and 9 (6.1%) (placebo, 5; dutasteride, 4) cases, respectively. ETV1 and ETV4 rearrangements were noted in 2 cases (1.4%) (placebo, 1; dutasteride, 1) and 1 (0.7%) (placebo, 1) case, respectively. No significant differences in the incidence of prostate cancer molecular aberrations between the groups were observed. There was no evidence that ETS fusion status was associated with disease progression.