Iranian Red Crescent Medical Journal IRCMJ 2009; 11(2):170-175 ©Iranian Red Crescent Medical Journal ORIGINAL ARTICLE Diagnostic Value of Prostate Specific Antigen and Its Density in Iranian Men with Prostate Cancer

Background: The specific threshold for prostate-specific antigen and density (PSA, PSAD) to delineate which patients are at the highest risk has been controversial. The purpose of this study was to evaluate the diagnostic value of PSA and PSAD in Iranian patients with prostate cancer. Methods: Three hundred men with the serum PSA greater than 4.0 ng/ml, abnormal digital rectal examination and/or suspicious transrectal ultrasound underwent transrectal ultrasound-guided prostate biopsies. PSAD was calculated by dividing the serum PSA in ng/ml by the volume of the entire prostate in cm3. Correlation with Glea-son grade of the tumor was also made. The patients were divided into three groups according to their PSA val-ues. The receiver operator characteristic (ROC) curve was produced from the raw data on all patients. Results: One hundred and two patients showed a cancer rate of 34%. The mean PSA and PSAD of the cancer group were significantly higher than those of the non-cancer group with better performance of PSAD as con-firmed by ROC curve. In patients with PSA levels between 4 and 10 ng/ml, mean PSAD values in positive and negative biopsy groups showed a significant difference while mean PSA values between these biopsy groups revealed no significant difference. The PSAD cutoff of more than 0.1 had higher sensitivity than 0.15 at the ex-pense of increasing the number of unnecessary biopsies. Among those the patients with PSA levels abov