TMPRSS2-ERG gene fusion and clinicopathologic characteristics of Korean prostate cancer patients.

OBJECTIVES

To survey the status of TMPRSS2-ERG fusion in Korean prostate cancer patients, we assessed the differences in clinicopathologic characteristics and biochemical recurrence according to TMPRSS2-ERG fusion status.

METHODS

The incidence of the TMPRSS2-ERG fusion gene was evaluated via fluorescence in situ hybridization (FISH) using ERG break-apart probes in 254 prostate cancer tissues resected by radical prostatectomy, and analyses of clinicopathologic parameters and biochemical recurrence were conducted.

RESULTS

The fusion rate of the TMPRSS2-ERG gene was 20.9% (53/254). TMPRSS2-ERG gene fusion was identified more frequently in patients with low Gleason grade (primary Gleason pattern ≤ 3 or sum of Gleason score ≤ 7, P = .015 and .027). Patients with large cribriform glands in Gleason pattern 4 harbored a rare TMPRSS2-ERG fusion gene compared with patients without large cribriform glands (P = .027). The incidence of biochemical recurrence did not differ according to TMPRSS2-ERG fusion gene status (P = .598).

CONCLUSIONS

ERG gene aberration did not correlate with biochemical recurrence of prostate cancers in Korean patients. Lower Gleason grade demonstrated higher rates of TMPRSS2-ERG fusion compared with high-grade tumors, including those demonstrating a large cribriform glands pattern. Prostate cancer with large cribriform glands revealed rare TMPRSS2-ERG gene fusion.