Prostate cancer (PCa) exhibits significant differences in prevalence and mortality among different ethnic groups. The underlying genetics is not well understood. TMPRSS2–ERG fusion is a common recurrent chromosomal aberration in PCa and is however not studied among different ethnic groups. We examined the prevalence and class of TMPRSS2–ERG gene fusion in PCa from Caucasian, African‐American, and Japanese patients.

A tissue microarray of PCa from 42 Caucasians, 64 African‐Americans, and 44 Japanese patients who underwent radical prostatectomies (RP) was studied for TMPRSS2–ERG fusion using a multicolor interphase fluorescence in situ hybridization assay for ERG gene break‐apart.

TMPRSS2–ERG gene fusion was present in 50% (21/42) of Caucasians, 31.3% (20/64) of African‐Americans, and 15.9% (7/44) of Japanese (P = 0.003). The gene fusion through translocation, deletion, or both occurred in 61.9% (13/21), 38.1% (8/21), and 0% (0/21) in Caucasians, 20% (4/20), 60% (12/20), and 20% (4/20) in African‐Americans, and 71.4% (5/7), 28.6% (2/7), and 0% (0/7) in Japanese patients (P = 0.02). A multivariate analysis demonstrated that TMPRSS2–ERG gene fusion correlated with the ethnicity (P = 0.03), marginally correlated with the pathologic stage (P = 0.06), but not other clinicopathologic parameters, including age, preoperative PSA levels, and Gleason score.

The prevalence and class of TMPRSS2–ERG are significantly different in PCa of Caucasian, African‐American, and Japanese patients. Future studies of the molecular pathways implicated in TMPRSS2–ERG gene fusion may shed light on the disparity in prevalence and mortality of PCa among different ethnic groups and help design better prevention and treatment strategies. Prostate 77:489–497, 2011. © 2010 Wiley‐Liss, Inc.