2008, Number 4
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ABSTRACTBackground: Prostate antigen density defined as the relation of the antigen value with total prostate volume is argued to be one of the diagnostic elements for prostate cancer in patients presenting with negative rectal examination and prostate antigen ‹10 ng/ml. It has been shown that this density can help predict biopsy positivity, decrease the number of unnecessary biopsies and predict the aggressiveness of the disease.
Materials and methods: A retrospective, crosssectional study was carried out which took into account all patients who had had prostate biopsies within the last 5 years at our hospital and studies determining initial prostate antigen, transrectal ultrasound measuring prostate volume and antigen density, transitional zone volume and density, histopathological results and Gleason score in cases of adenocarcinoma, number of positive fragments and their percentages. Statistical analysis was carried out to evaluate sensitivity and specificity of different cut–off point values.
Results: From a total of 747 biopsies, 260 patients met with all established inclusion criteria. Mean age was 68 years with a range from 43 to 88 years. Mean prostate antigen was 23.26 with a range from 0.6 to 623 ng/dL. Prostate density varied from 0.01 to 5.08 ng/ml. When cut –off point value was 0.17 ng/mL/cc there was 77% sensitivity, a 60% specificity and 87% negative predictive value.
Conclusions: A cut-off point of 0.17 ng/mL/cc is helpful in adequately predicting the absence of cancer in prostate biopsies.
Morote. Comparison of percent free prostate specific antigen and prostate specific antigen density as methods to enhance prostate specific antigen specificity in early prostate cancer detection in men with normal rectal examination and prostate specific antigen between 4.1 and 10 ng/mL. J Urol 1994;158:502.