Predictive significance of TMRPSS2 - ERG fusion in prostate cancer: a meta-analysis.

Background: Prostate cancer is a major malignancy in males. TMPRSS2 - ERG is a high-frequency fusion gene expressed in prostate cancer and plays a vital role in carcinogenesis. Recent studies showed that TMPRSS2 - ERG is a potential predictive biomarker for prostate cancer. However, the predictive value of TMPRSS2 - ERG fusion is yet unclear.

Methods: A total of 76 relevant articles, published from 2015 to 2017, were obtained from PubMed, Web of Science, EMBASE, Scopus, the Cochrane Library, and CNKI databases to investigate the predictive significance of TMPRSS2 - ERG fusion in prostate cancer. Pooled odds ratio (ORs) with 95% confidence intervals (CIs) were calculated to estimate the correlation between TMPRSS2 - ERG fusion gene and tumor features.

Results: The pooled or stratified analysis showed that the TMPRSS2 - ERG fusion gene had a highly predictive potential. First, TMPRSS2 - ERG fusion was associated with T-stage at diagnosis (T3-4 vs. T1-2 OR: 1.40; 95% CI 1.33-1.48) and metastasis (M1 vs. M0 OR: 1.35; 95% CI 1.02-1.78) but not with biochemical recurrence or prostate cancer-specific mortality. Furthermore, the subgroup analysis found that the TMPRSS2 - ERG fusion gene was correlated with Gleason (G) scores, and the fusion was common in prostate cancer with G ≤ 7. Additionally, the meta-analysis demonstrated that the fusion was likely to occur in young patients (> 65 vs. ≤ 65 OR: 0.68; 95% CI 0.52-0.89), in patients with high PSA levels (> 10 vs. ≤ 10 OR: 1.30; 95% CI 1.21-1.38), and in patients with peripheral involvement (positive vs. negative OR: 1.17; 95% CI 1.08-1.28), while not associated with tumor volume. Finally, the subgroup analysis of different fusion types demonstrated that the deletion-type fusion was significantly associated with the malignant degree of prostate cancer (pooled OR: 5.67; 95% CI 2.85-11.28). Moreover, the deletion-type was common in Africa patients, followed by Caucasian patients, and no significant difference was observed in the incidence of different fusion types in the Asian population.

Conclusions: The meta-analysis findings suggested that the TMPRSS2 - ERG fusion gene might be a predictive marker for prostate cancer patients, and might be valuable for assessing the characteristics of prostate cancer for individualized treatment and prognosis evaluation.