New indicator for prostate gland biopsy when malignancy is in question

The aim of our study was to find out a new indicator with a higher specificity level than prostate prostate-specific antigen (PSA) in order to achieve a better selection of patients who will undergo prostate biopsy. Trans-rectal ultrasound-guided prostate biopsy was performed in 135 patients who had elevated PSA level and/or palpable nodule on digital rectal examination. The PSA level was ≤10 ng/mL in 81 patients and >10 ng/mL in 54 patients. We designed a new formula consisting of prostate volume, patient′s age, and free prostate specific antigen. Its resultant was defined as prostate biopsy index and was compared with the most currently used parameters. Histology results yielded prostate gland malignancy in 40 (30%) patients. Our new index differed significantly between the malignant and the non-malignant patient categories (P = 0.01). The ROC curve analysis at different specificity and sensitivity levels (85%, 90% and 95%) and regarding the area under the curve (AUC), our new index was significantly better than the other studied parameters (P = 0.001). Additionally, the AUC in patients with a PSA level ≤10 ng/mL and bet-ween 10.1 and 20 ng/mL was 0.75 and 0.78, with a sensitivity of 91% and 83% and a specificity of 24% and 73%, respectively, at a cut-off point of 1.7. The overall sensitivity and specificity at the same point were 80% and 41%, respectively. In conclusion, the performance of our new index was superior to all other evaluated parameters. At 83% sensitivity with a cut-off point of 1.7, 63.5% of the performed biopsies could have been avoided in patients with a PSA level between 10.1 and 20 ng/mL

Utility of free prostate specific antigen serum level and its related parameters in the diagnosis of prostate cancer

We evaluated the role of free prostate specific antigen (f-PSA) serum level and its related parameters in detecting prostate cancer. This retrospective study was conducted between January 2006 and March 2008. Trans-rectal ultrasound guided prostate biopsy was performed for 107 patients who had total PSA (t-PSA) level of either >4 ng/mL with or without palpable nodule or ≤4 ng/mL with palpable nodule on digital rectal examination. The perfor-mance measurements for f-PSA, percent free PSA (%f-PSA) and free PSA density (f-PSAD) were determined and compared with those for t-PSA and total PSA density (t-PSAD). Descriptive statistics for all variables of interest were calculated, and receiver operating characteristic curves were generated. Nine patients (8.4%) had normal histology, 69 patients (64.4%) had benign disease and 29 patients (27.1%) had prostate cancer. The performance of f-PSA in PCa detection was better than other evaluated parameters. The largest area under the curve for patients in the gray area (t-PSA range 4.1-10 ng/mL) was for f-PSA, with a value of 0.64 and a sensitivity and specificity of 44% and 87%, respectively. For %f-PSA, these values were 0.59, 63% and 62%, respectively. For patients with a t-PSA level of 10.1-20 ng/mL, they were 0.68, 67%, and 81%, respectively, for f-PSA, and 0.64, 67%, and 76%, respectively, for %f-PSA. In conclusion, f-PSA serum levels performed better than free to total PSA ratio and t-PSA for prostate cancer screening. It is of clinical value which could affect the biopsy decision avoiding unnecessary interventions