Diagnostic accuracy of percent free prostate-specific antigen in prostatic pathology and its usefulness in monitoring prostatic cancer patients.

INTRODUCTION: The aim of our study was to evaluate the clinical usefulness of percent free prostate-specific antigen (PSA) [ratio of free PSA (fPSA) to total PSA (tPSA); f/tPSA] in prostatic pathology and its usefulness in monitoring prostatic cancer patients. PATIENTS AND METHODS: Our prospective study was carried out on 470 consecutive male patients referred to our outpatient urological clinic for observation. We looked for relationships between tPSA, fPSA and percent free PSA and the patient's age, prostatic volume and histologic diagnosis as assessed by prostatic biopsies or surgical specimens (benign prostatic hypertrophy, carcinoma, hypertrophy with inflammation). In all cases, we calculated the specificity, sensitivity and diagnostic accuracy of percent free PSA in the diagnosis of prostatic diseases, using cutoff values ranging from 14 to 20%. In prostatic cancer patients, we considered the relationships between the various PSA molecular forms and staging, grading and follow-up values. We also evaluated the effects of hormonosuppressive therapy on the serum markers and noted for which tPSA value percent free PSA possessed the greatest diagnostic accuracy. RESULTS: While tPSA and fPSA values appeared to be correlated with patient age and prostatic volume, percent free PSA did not show a relationship with these parameters. The specificity, sensitivity and overall diagnostic accuracy were better assuming a 16% cutoff value for percent free PSA than with other cutoff values. Prostatic inflammation associated with benign hypertrophy can cause false positives in both tPSA and f/tPSA measurements, since 60% of these patients have an f/tPSA ratio below 16%. In diagnosing carcinoma, the diagnostic accuracy of percent free PSA is 100% when tPSA is between 2.5 and 4.0 ng/ml. Percent free PSA is not linked with staging in prostatic cancer, but it does appear to be related to the Gleason score. In patients receiving hormonosuppressive treatment, f/tPSA decreased significantly, and more so in patients with a higher Gleason score. In patients with disease in rapid progression, percent free PSA was lower than in patients in a stable condition. CONCLUSIONS: Based on our experience, 16% as the f/tPSA cutoff value for discriminating between benign and malignant pathologies is the best possible choice, as it provides the highest overall values of sensitivity, specificity and diagnostic accuracy (80, 61.5 and 84.5%, respectively) in the diagnosis of prostatic cancer. We believe that f/tPSA is not a definitive test for diagnosing prostatic cancer. Our observations on the behavior of percent free PSA in relation to prostatic carcinoma grading and staging and in the follow-up of carcinoma patients are interesting; however, further studies are needed to define the appropriate role of f/tPSA in patients with an established diagnosis of prostatic carcinoma and in the follow-up of patients with prostatic cancer.

Pressure-flow studies in men with benign prostatic hypertrophy before and after treatment with transurethral needle ablation.

BACKGROUND/AIMS: In this study we wanted to examine the effects that transurethral needle ablation (TUNA) might have on the urodynamic characteristics of bladder outlet obstruction and to evaluate the clinical changes and the safety profile in patients undergoing the TUNA procedure, including the effects on erectile and ejaculatory function. MATERIALS AND METHODS: We evaluated 24 patients, aged between 66 and 81 (mean 73.4) years with a mean prostatic volume of 57 +/- 15 ml. Before treatment, the clinical history was collected, then prostate-specific antigen (PSA) analysis, digital rectal examinations, I-PSS and quality-of-life (QOL) tests, uroflowmetry with residual volume, and pressure-flow studies were performed in all patients. After treatment, all the patients were evaluated at 6, 12 and 24 months by the same parameters. RESULTS: After treatment, the I-PSS and QOL scores were considerably improved, and the mean flow rate and the residual volume were also improved. The serum PSA level remained unchanged. The prostatic volume was almost unchanged, and pressure-flow studies showed a reduction in the mean opening pressure and detrusor pressure at maximum flow after treatment. None of the patients complained of alterations in sexual activity nor retrograde ejaculation. CONCLUSIONS: Our study confirms that in patients with benign prostatic hyperplasia, the TUNA procedure results in no major complications and in significant clinical improvements. There was an improvement in the subjective and objective variables, such as symptom scores and frequency-volume charts and, in the majority of patients, subjective and objective improvements were sustained for the duration of this study, which included a 2-year follow-up with pressure-flow studies. From our experience we can say that the ideal candidate for TUNA treatment should be younger than 70 years, with a prostatic volume of <60 cm H(2)O, with a baseline detrusor pressure at maximum flow of <60 cm H(2)O, with a pretreatment residual volume of <100 ml and with a QOL score of <5.

[Diagnostic efficacy of free SPA/total PSA ratio in the diagnosis of prostatic carcinoma]. / Efficacia diagnostica del rapporto PSA-free/PSA totale nella diagnosi del carcinoma prostatico.

Prostate specific antigen, specific organ and tissue marker, is a glycoprotein present in serum in different molecular forms, i.e. not protein bound and bound to proteins (PSA-ACT and PSA-AMG). The total PSA is expressed by the sum of the non protein bound value (free-PSA) and PSA-ACT. The aim of our study was to evaluate the hypothesis that measurement of free/total PSA ratio may be helpful in the differential diagnosis of prostatic pathology. Our study was conducted on 350 patients, to whom the total-PSA, free-PSA and f/t PSA had been performed; 250 patients showed a total PSA between 2.5 and 10 ng/ml and 185 of them had symptoms of bladder out-flow obstruction. In all of the 250 patients digital rectal examination, transrectal ultrasound and prostatic biopsy were performed. 100 patients were controls. The cut-off to differentiate between benign and malignant prostatic disease was 16%. The pathologic diagnosis was related to the f/t PSA ratio, and in particular those patients with a f/t PSA lower than 16% were expected to be prostatic carcinoma, while those with a f/t PSA higher than 16% were expected to be benign prostatic hypertrophy. The diagnostic accuracy of the ratio was calculated, and it was observed that it was 88.65% in the diagnosis of benign prostatic hypertrophy, while in the diagnosis of prostatic carcinoma it was 84.5%. We can therefore assume that f/t PSA can add useful information on prostatic pathology, eventually sparing unnecessary prostatic biopsies.