Can the intraprostatic concentration of epidermal growth factor influence the variance of serum prostate specific antigen levels in patients with benign prostatic hyperplasia?

Purpose: Except for prostate volume, little is known about the factors infl uencing serum prostate specific antigen (PSA) levels. Considering that dihy drotestosterone and epidermal growth factor are regulators of the prolifera tion and differentiation in the epithelial component of human prostate tiss ue and that PSA is produced only by the epithelial cells of the gland, stud ies were performed on patients with a histological diagnosis of benign pros tatic hyperplasia (BPH) to establish whether a significant association exis ts between the intraprostatic concentration of dihydrotestosterone or epide rmal growth factor and serum PSA levels. Materials and Methods: A total of 20 patients with BPH who had not been pre viously treated were part of a larger study on the correlation among PSA, p rostate volume and age, and were evaluated according to the algorithm in th e guidelines of the international consultation on BPH. All men underwent op en suprapubic prostatectomy to enucleate the entire adenoma and in each cas e sections were made in the periurethral, subcapsular and intermediate zone s of the BPH tissue. Dihydrotestosterone and epidermal growth factor concen trations were evaluated by radioimmunoassay in the periurethral zone and in total BPH tissue. Results: In these 20 patients with BPH serum PSA levels were significantly associated with epidermal growth factor but not with dihydrotestosterone co ncentrations in total BPH tissue (r = 0.7762, p = 0.00002836 and r = 0.3923 , p = 0.0956307, respectively). A stronger association was found between PS A levels and the periurethral concentration of epidermal growth factor and dihydrotestosterone (r = 0.8117, p = 0.000005 and r = 0.5656, p = 0.0098326 , respectively). On the contrary, epidermal growth factor and dihydrotestos terone were not significantly associated with prostate volume (p = 0.957415 and p = 0.531439, respectively). Conclusions: To our knowledge this study is the first report in the literat ure to demonstrate an association between serum PSA, and dihydrotestosteron e and epidermal growth factor levels, particularly in the periurethral zone of human BPH tissue. These data suggest the importance of epidermal growth factor and dihydrotestosterone in influencing serum PSA levels.