Value of Percentage of Free serum Prostatic Specific Antigen In Diagnosis of Prostate Cancer In Patients with PSA (4-10 ng/ml)

Our study aimed to assess the role of percentage free PSA in the detection of prostate cancer in patients lie within the grav zone (4-10ng/ml).The study included 50 patients with age range from 40-85 years presented to Urology Outpatient Clinic of Zagazig University Hospitals from December 2004 to May 2006.This study was performed to demonstrate the value of percentage free PSA in differentiating benign from malignant lesions and help in selection of cases for biopsy.The results were that percentage free PSA is one of the best tests used to increase specificity of PSA and maintain high sensitivity.In our study, we found that use of 25% of less as cutoff can score sensitivity about 93.5% and specificity about 80% and maker eduction in the unnecessary biopsies by 58%.In conclusion, methods other than measurement of percent free PSA have also been proposed to enhance the specificity of PSA screening, such as age-specific PSA reference ranges, PSA density, and PSA velocity. However, all of these methods have limitations .Age-specific PSA reference ranges have been shown to miss the cancer in a substantial percentage of cases. PSA density requires atransrectal ultra sonographic estimate of prostate volume, this is a more costly, inconvenient, and technique-dependent procedure than a blood test. PSA velocity requires at least three blood sample measurements over an 1S-month period to determine a clinical pattern. Thus, this approach may be invalidated if laboratories change their PSA methods or if samples are tested by different laboratories using different methods. In contrast, use of the percent free PSA maintains a high cancer detection rate, requires only a single blood sample, and is convenient and relatively inexpensive compared with other methods.