Androgen Receptor CAG Repeat Length is Not Associated with the Risk of Incident Symptomatic Benign Prostatic Hyperplasia: Results from the Prostate Cancer Prevention Trial

摘要

This study examined whether androgen receptor (AR) CAG repeat length was associated with the risk of incident benign prostatic hyperplasia (BPH), in a nested case-control study of 416 BPH cases and 527 controls drawn from Prostate Cancer Prevention Trial placebo-arm participants who were free of BPH at baseline. BPH was assessed over 7 years and was defined as receipt of medical or surgical treatment, two scores >14 on the International Prostate Symptom Score (IPSS), or two increases in IPSS ≥ 5 with at least one score ≥ 12. There were no associations of AR CAG repeat length and BPH risk. Compared to men with AR repeat length ≤19, the covariate-adjusted odds ratios [95% CI] were 1.07 [0.73, 1.57] and 0.90 [0.55, 1.45]) for repeat length 20–24 and ≥25, respectively. There was a weak association of AR repeat length with baseline serum testosterone (T) (Spearman r=0.09, p<0.02); however, control for or stratification by T did not change study results. Further, results did not differ when stratified by body mass index, baseline IPSS, or baseline concentration of 3α-diol glucoronide, and were similar for all BPH definitions. This study suggests that knowledge of AR CAG repeat length will have little clinical utility for the prevention of symptomatic BPH.