TMPRSS2:ERG fusion gene occurs less frequently in Chinese patients with prostate cancer.

Prostate cancer is the commonest male malignancy in the Western world, but its morbidity is much lower in China. The principal aim of this study was to evaluate the frequency of TMPRSS2:ERG fusion in Chinese prostate cancer patients using immunohistochemistry and reverse transcription polymerase chain (RT-PCR). In addition, we compared the ERG protein expression with TMPRSS2:ERG fusion gene. The relationship between ERG expression and clinicopathologic features was also examined. Samples from patients who underwent radical prostatectomies in Changhai Hospital (Shanghai, China) were collected and stored in ethically approved tissue banks. One hundred seventy-four prostate cancer tissue samples and 10 normal tissues were marked on standard hematoxylin-eosin (HE) sections, punched out of the paraffin blocks and inserted into a recipient block using tissue arrayer instruments. Immunohistochemistry and RT-PCR were employed to detect TMPRSS2:ERG fusion gene. ERG was highly expressed in the nuclei of endothelial cells of vessels and weak cytoplasmic staining was occasionally observed. ERG positive staining was present in 14.9 % (26/174) of the tumor samples in microarray. All benign prostate samples were found to be negative. RT-PCR results revealed that 11.1 % (15/135) were TMPRSS2:ERG fusion positive. Altogether, there was a good agreement of ERG immunostaining with the presence of TMPRSS2:ERG. However, no correlation was observed between ERG expression and age, Gleason score, stage, surgical margin, and seminal vesicle involvement in Chinese patients. In the present study, we identified a high correlation between ERG expression and ERG TMPRSS2:ERG, with 100 % sensitivity and 88.9 % specificity. The expression level of ERG was unrelated to the age, Gleason score, stage, surgical margin, and seminal vesicle involvement. Therefore, the association between ERG expression and prostate cancer based on Chinese population should be further investigated in the future.