Association between androgen receptor gene polymorphisms and testicular germ cell tumor: A systematic review and meta-analysis

Objective: To estimate association between androgen receptor (AR) gene polymorphisms and testicular germ cell tumor (TGCT) susceptibility. Materials and Methods: Systematic search of studies on the association between AR gene polymorphisms and TGCT susceptibility was conducted. Odds ratios and 95% confidence intervals were used to pool effect size. Results: For CAG repeat, no evidence was found for association between (25 vs. %25), (25 vs. 21u25), (<21 vs. 21u25), (others vs. 21u25), (23 vs. %23), (<21 vs. >= 21), (<21 vs. >= 21)'s some subgroups and TGCT susceptibility, which showed stability. In (24 vs. %24), (24 vs. 21u24), (<21 vs. 21u24), and (others vs. 21u24) and almost all of their subgroups, increased TGCT risk was found without sensitivity analysis. For GGN, no statistical change of TGCT risk was found in (<23 vs. >= 23), (<23 vs. 23), which showed stability. For single nucleotide polymorphism (SNP) rs6152 G A, rs1204038 G A and rs2361634 A G, no statistical change was found without sensitivity analysis. Conclusions: GGN repeat number <23 may not be associated with TGCTs susceptibility. However, there was insufficient data to fully confirm association in GGN repeat number 23, CAG repeat number, SNP rs6152, rs1204038, and rs2361634.