Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 44 11 2015 11 25 1466 1472 Xin LIU Jie TANG Xiang FEI Qiu-Yang LI 2015 11 25 2015 11 25 Background: We aimed to value the usefulness of free to total prostate-specific antigen and Prostate-specific antigen (PSA) density for prostate cancer in the patients with PSA levels of 4.0 ng/ml or less. Methods: A total of 343 subjects with PSA levels of 4.0 ng/ml or less were biopsied. All patients were divided into four groups according to the PSA levels: 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml. The reliability of cancer detection in relation to the f/t PSA ratio and PSAD were estimated. Results: Overall, 65 people were diagnosed with prostate cancer. The detection rate was 16.28%、17.17%, 21.82%, 25.00% in subjects with PSA levels of 0 to 1.0 ng/ml, 1.1 to 2.0 ng/ml, 2.1 to 3.0 ng/ml, and 3.1 to 4.0 ng/ml, respectively. The f/t PSA ratio was significantly lower in patients with prostate cancer and PSA levels of 2.1 to 4.0 ng/ml (P＜0.05). The PSAD had no statistical significance between the two groups. Conclusions: Routine prostate biopsy should be undertaken if the f/t PSA ratio less than 15% with /without abnormal DRE/TRUS findings.   Keywords: Biopsy, Prostate cancer, Prostate-specific antigen, PSA ratio, PSAD  https://ijph.tums.ac.ir/index.php/ijph/article/view/5302 https://ijph.tums.ac.ir/index.php/ijph/article/download/5302/4522