Background: The percentage of free prostate-specific antigen (%fPSA) has been shown to improve specificity for the diagnosis of prostate cancer (PCa) over total PSA (tPSA). A multicenter study was performed to evaluate the diagnostic value of a %fPSA-based artificial neural network (ANN) in men with tPSA concentrations between 2 and 20 μg/L for detecting patients with increased risk of a positive prostate biopsy for cancer. Methods: We enrolled 1188 men from six different hospitals with PCa or benign prostates between 1996 and 2001. We used a newly developed ANN with input data of tPSA, %fPSA, patient age, prostate volume, and digital rectal examination (DRE) status to calculate the risk for the presence of PCa within different tPSA ranges (2–4, 4.1–10, 2–10, 10.1–20, and 2–20 μg/L) at the 90% and 95% specificity or sensitivity cutoffs, depending on the tPSA concentration. ROC analysis and cutoff calculations were used to estimate the diagnostic improvement of the ANN compared with %fPSA alone. Results: In the low tPSA range (2–4 μg/L), the ANN detected 72% and 65% of cancers at specificities of 90% or 95%, respectively. At 4–10 μg/L tPSA, the ANN detected 90% and 95% of cancers with specificities of 62% and 41%, respectively. Use of the ANN with 2–10 μg/L tPSA enhanced the specificity of %fPSA by 20–22%, thus reducing the number of unnecessary biopsies. Conclusions: Enhanced accuracy of PCa detection over that obtained using %fPSA alone can be achieved with a %fPSA-based ANN that also includes clinical information from DRE and prostate volume measurements.

Objective To evaluate the need for a bone scan as a routine staging procedure in patients with newly diagnosed prostate cancer in relation to serum prostate-speci®c antigen (PSA) and alkaline phosphatase (ALP) levels, and thus determine whether a reduction of the use of this staging method is possible in patients with a low probability of osseous metastasis. Patients and methodsThe results of bone scans were related retrospectively to levels of serum PSA and ALP in 363 patients with prostate cancer newly diagnosed between 1989 and 1997. Results Of 363 consecutive patients, 111 had a positive bone scan. In 19 of 144 (13%,`missed diagnosis') patients with a PSA level of <20 ng/mL the bone scan was positive. In 125 patients (49%,`false-positives') with a PSA level of >20 ng/mL the bone scan was negative. A threshold level of 100 U/L for ALP gave a better balance for the number of`false-positives' and missed diagnosis'. ALP values correlated better with an abnormal bone scan than did PSA levels; ALP levels of >90 U/L indicated a 60% chance for the presence of bone metastases. Conclusion Patients with newly diagnosed and untreated prostate cancer should undergo bone scintigraphy if there is bone pain or if ALP levels are >90 U/L. Recent reports discourage the routine use of a bone scan when the serum PSA level is <20 ng/mL. However, the present series suggests there is a greater chance of a positive bone scan in patients with low PSA levels; these ®ndings need further con®rmation.

Our results show the applicability of a TRAP assay to measure telomerase activity in small needle biopsied prostate samples. In poorly differentiated and metastatic cancer we observed that levels of telomerase activity were high. To establish accuracy and to distinguish the 'relative good from the ugly' further study is needed.

Objective To assess the predictive role of the bone markers alkaline phosphatase (ALP) and urinary deoxypyridinoline (DPD), as indicators of bone turnover, at baseline in patients with prostate cancer. Patients, subjects and methods Urinary DPD, serum ALP and prostate-speci®c antigen (PSA) were evaluated in 23 patients with benign prostatic hyperplasia (BPH), 115 with prostatic carcinoma, of whom 21 had bone metastasis, and in 16 age-matched control subjects. Results Patients with newly diagnosed prostate cancer and bone metastasis had a higher urinary excretion of DPD, and a higher serum PSA and ALP than had patients with BPH and those with prostate cancer but no metastasis. Receiver operating curve analysis for PSA, ALP and DPD showed a signi®cant discriminating ability for positive and negative bone scans (P=0.0684). However, from logistic regression of the combinations, only serum ALP was a signi®cant independent predictor of bone metastasis in patients with prostate cancer. Conclusion Serum ALP or urinary DPD are the best predictors of bone metastasis in patients with prostate cancer; further studies with more patients are required.