Correlation between serum prostate specific antigen and prostate volume in benign prostatic hyperplasia.

Thesis Report.

ABSTRACT: Benign prostatic hyperplasia (BPH) is one of the commonest diseases affecting the elderly men. By the age of 60 years, 50% of men have histologic evidence of BPH. Prostate specific antigen (PSA) is a serine protease secreted by the prostate epithelium. In the majority of men with elevation of serum PSA, the likely reason for the elevation is benign enlargement of the prostate, not the prostatic cancer because of the much higher prevalence of BPH in the population. Prostatic manipulation (prostatic massage, digital rectal examination and prostate biopsy) and prostatitis are other causes of raised serum PSA level. Studies have shown that in BPH, PSA level is much higher than that in tumor In prostatic carcinoma, PSA level is much higher than that in BPH and it is disproportionate to the volume of the tumor. The relationship between prostate volume and serum PSA level would, thus help in distinguishing between men with BPH and those with prostatic carcinoma. A prospective study of patients with BPH was conducted in Tribhuvan University Teaching Hospital (TUTH) over a period of one and a half- year. Fifty patients were included in the study. All the patients had serum PSA estimation which was followed by estimation of prostate volume by transrectal ultrasonography (TRUS) as well as by digital rectal examination (DRE). Prostatic carcinoma was ruled out by histopathological study of the prostatic specimen after prostatectomy. All the patients were >_ 50 years of age with men age 68.76 _+8.90 years. 78% of patients had predominantly obstructive symptoms and rest had predominantly irritative symptoms at presentation. Mean PSA level was 4.26 +_3.25 ng/ml with range 0.3-14.6ng/ml. Mean prostate volume measured by TRUS was 46.24+_ 19.04ml and that by DRE was 35.70_+ 10.54ml. There was a strong positive linear correlation between PSA level and prostate volume measured by TRUS with Pearson's correlation coefficient r=0.776 (p<0.0001). Regression coefficient of PSA on prostate volume was calculated as y=0.132x- 1.860 Where y =serum PSA in ng/ml and x + prostate volume in ml. Thus it was concluded that a linear positive correlation exists between serum PSA level and prostate volume in BPH. Key Words: PSA, TRUS, BPH, correlation.

Eng.