Introduction and Objectives
According to a secondary analysis on patients enrolled in PCPT, finasteride seems to improve accuracy of PSA in diagnosis of prostate cancer. However, PCPT was designed specifically to evaluate the efficacy of finasteride for chemoprevention of prostate cancer. Our aim is to evaluate, in a prospective study, the diagnostic accuracy of PSA in patients with prior negative prostate biopsy findings who were given finasteride for 6 months.
Material and Methods
We evaluated the diagnostic accuracy of PSA in detecting prostate cancer in rebiopsy series. The study cohort consisted of 91 men with prior negative biopsy findings, including HGPIN and excluding ASAP. All patients were instructed to take finasteride 5 mg daily for 6 months. Prostate biopsy was repeated at 6 months and the findings were compared to the initial results. PSA levels were measured at study onset and after 1, 3 and 6 months. We calculated the ROC curve of PSA under the effect of finasteride for detecting prostate cancer. All patients were evaluated at study onset and after 6 months by clinical examination, digital rectal exploration (DRE), International Prostate Symptom Score (IPSS) and National Institutes of Health Chronic Prostatitis Symptom Index (NHICPSI).
Results
The mean patient age was 68 years (66.7–69.4). The mean PSA level was 7.48 ng/ml (6.06–8.89). 84 patients completed the study with rebiopsy; 14 of these patients refused the rebiopsy. 7 were lost to follow-up due to poor compliance. Of the 70 patients, 13 were diagnosed with prostate adenocarcinoma. The median PSA level decreased similarly both in those with prostate cancer and in those without findings of cancer. There was no statistically significant difference between the two groups. The areas under ROC curve (AUC) of PSA at study onset and after 6 months of therapy with finasteride were, respectively, 0.484 (95% CI 0.363 to 0.606) and 0.543 (95% CI 0.420 to 0.663) (Figure 1). There was no statistically significant difference between the two areas.
Conclusions
The results of our study show that PSA itself has a low diagnostic accuracy for detecting prostate cancer in men with prior negative prostate biopsy findings. Finasteride does not improve the accuracy of PSA in this population of patients.
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© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.