CUT-OFF VALUES OF PROSTATE SPECIFIC ANTIGEN DENSITY– AN EFFECTIVE SCREENING MARKER BEFORE PROSTATE BIOPSY

OBJECTIVE: To determine cut-off values for prostate specific antigen density (PSAD) in diagnosing prostate carcinoma in symptomatic patients. METHODS: This cross sectional, observational study conducted at Department of Chemical Pathology and Endocrinology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan from June 2020 to May 2021. Symptomatic patients (309) having prostatic enlargement on ultrasound were selected through consecutive sampling. All the patients underwent prostate biopsy for histopathological diagnosis. Prostate specific antigen density was calculated and compared between different age groups and different diseases. ROC curve was constructed and area under the curve was calculated to find out cut-off values value for PSAD. Sensitivity, specificity and accuracy were calculated at the cut-off values. RESULTS: Among 309 patients of median age was 68 years (IQR 43 – 75). There was a significant difference of PSAD in different age groups (p<0.001) and diseases like prostate carcinoma, benign prostatic hyperplasia and other prostatic disorders. PSAD had AUC of 0.878 at cut-off value of 0.135 ng/ml where sensitivity was 100%. A higher cut-off 0.20 ng/ml was suggested in younger age group as compared to the old age group where cut-off was found 0.135. CONCLUSION: Using PSAD as part of evaluation profile for prostate lesion, number of unnecessary biopsies can be significantly decreased. PSAD cut-off to aid in decision of invasive prostate biopsy is suggested to be 0.135 ng/ml with close biochemical follow up afterwards.