ObjectivesTo compare the predictive performance and potential clinical usefulness of risk calculators of the European Randomized Study of Screening for Prostate Cancer (ERSPC RC) with and without information on prostate volume.MethodsWe studied 6 cohorts (5 European and 1 US) with a total of 15,300 men, all biopsied and with pre-biopsy TRUS measurements of prostate volume. Volume was categorized into 3 categories (25, 40, and 60 cc), to reflect use of digital rectal examination (DRE) for volume assessment. Risks of prostate cancer were calculated according to a ERSPC DRE-based RC (including PSA, DRE, prior biopsy, and prostate volume) and a PSA + DRE model (including PSA, DRE, and prior biopsy). Missing data on prostate volume were completed by single imputation. Risk predictions were evaluated with respect to calibration (graphically), discrimination (AUC curve), and clinical usefulness (net benefit, graphically assessed in decision curves).ResultsThe AUCs of the ERSPC DRE-based RC ranged from 0.61 to 0.77 and were substantially larger than the AUCs of a model based on only PSA + DRE (ranging from 0.56 to 0.72) in each of the 6 cohorts. The ERSPC DRE-based RC provided net benefit over performing a prostate biopsy on the basis of PSA and DRE outcome in five of the six cohorts.ConclusionsIdentifying men at increased risk for having a biopsy detectable prostate cancer should consider multiple factors, including an estimate of prostate volume.

Purpose: The relationship between prostate-specific antigen (PSA) level and prostate cancer risk remains subject to fundamental disagreements. We hypothesized that the risk of prostate cancer on biopsy for a given PSA level is affected by identifiable characteristics of the cohort under study.Experimental Design: We used data from five European and three U.S. cohorts of men undergoing biopsy for prostate cancer; six were population-based studies and two were clinical cohorts. The association between PSA and prostate cancer was calculated separately for each cohort using locally weighted scatterplot smoothing.Results: The final data set included 25,772 biopsies and 8,503 cancers. There were gross disparities between cohorts with respect to both the prostate cancer risk at a given PSA level and the shape of the risk curve. These disparities were associated with identifiable differences between cohorts: for a given PSA level, a greater number of biopsy cores increased the risk of cancer (odds ratio for >6-versus 6-core biopsy, 1.35; 95% confidence interval, 1.18-1.54; P < 0.0005); recent screening led to a smaller increase in risk per unit change in PSA (P = 0.001 for interaction term) and U.S. cohorts had higher risk than the European cohorts (2.14; 95% confidence interval, 1.99-2.30; P < 0.0005).Conclusions: Our results suggest that the relationship between PSA and risk of a positive prostate biopsy varies, both in terms of the probability of prostate cancer at a given PSA value and the shape of the risk curve. This poses challenges to the use of PSA-driven algorithms to determine whether biopsy is indicated. Clin Cancer Res; 16(17); 4374-81. ©2010 AACR.

This paper won First Prize in the 2003 AUA -Ambrose/Reed Socioeconomics Essay Contest curves were generated and compared using log-rank tests. The Cox proportional hazards method was used for analyses involving adjustments for potential confounding factors. RESULTSThe surgical treatment rate was 17% for African-American and 28% for White patients ( P < 0.001). In those patients treated conservatively or by radiation therapy, both crude and cancer-specific survival rates were lower for African-Americans than for Whites ( P < 0.001). However, for patients undergoing surgery, differences in survival between African-Americans and Whites were not statistically significant. According to our models, SES explained 50% and surgical treatment rates ≈ 34% of the differences in survival between African-Americans and Whites. CONCLUSIONSThis analysis suggests that the lower prostate cancer survival rates for the AfricanAmericans in the present population can be largely explained by differences in SES and lower surgical treatment rates. Efforts to increase awareness of treatment options among African-American patients may be a way of improving survival in this group.