Purpose: A single nucleotide polymorphism with adenine (A) to guanine (G) substitution is identified at position -158 in the androgen response elements region of the prostate specific antigen (PSA) gene. We evaluated the relationship between the PSA -158A/G polymorphism and the risk, tumor volume and pathological stage of prostate cancer.
Materials and methods: Peripheral venous blood samples were obtained from 122 patients with prostate cancer and 84 controls with benign prostatic hyperplasia. The diagnosis, tumor volume and pathological stage of prostate cancer were all determined according to the pathological reports of transrectal ultrasound guided prostate biopsy, transurethral prostate resection and radical prostatectomy. The PSA -158A/G polymorphism was determined by polymerase chain reaction based restriction fragment length polymorphism methods.
Results: Patients with prostate cancer had significantly greater frequencies of the G allele (87.3% vs 77.4%) and GG genotype (78.7% vs 61.9%) than the control group (p = 0.008 and 0.028, respectively). The OR of GG to AG and AA was 2.27 (p = 0.008). In the prostate cancer group the GG genotype was also associated with larger tumor volume (2.34 vs 0.82 ml) and higher pathological stage (organ confined cancer 68.2% vs 31.8% and extracapsular extension 100% vs 0%) than the GA and AA genotypes (p = 0.013 and 0.036, respectively).
Conclusions: The PSA -158A/G polymorphism is associated with prostate cancer. The G allele increases the risk of prostate cancer and the GG genotype is associated with larger tumor volume and higher pathological stage.