Two such tools are the Prostate Cancer Prevention Trial Risk Calculator (PCPT-RC) and the European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculator (ERSPC-RC). These prediction tools incorporate known risk variables such as age, PSA, DRE, family history of CaP, ethnicity, prior negative prostate biopsy, and 5-ARI usage among others to generate an assigned risk of CaP. In the British Journal of Urology International, Dr. Greg Trottier and colleagues from Toronto and Erasmus compared the PCPT-RC and ERSPC-RC in a cohort of 982 Canadian men. They found that the ERSPC-RC performed better.
Between 2008 and 2010, the 982 men were evaluated and underwent an 11-core prostate biopsy if it was a first time biopsy and a 15-core sampling to include the transition zone if it was a repeat biopsy. Men taking 5-ARIs had their PSA values doubled. The data was put into the online calculators and ROC curves generated for the prediction of CaP. The cohort was divided into 10 groups with 98 or 99 men, sorted by increasing predicted risk of CaP. The characteristics of the study cohort differed from the characteristics of either risk calculator cohort, primarily with respect to age, ethnicity, number of prostate biopsy cores and indications. What the investigators found was CaP in 46% and high-grade disease in 23% of those undergoing prostate biopsy. They found that a positive family history was associated with a diagnosis of CaP, but not high-grade disease. A greater odds of CaP or high-grade CaP was associated with increasing age, previous negative biopsy, abnormal DRE, TRUS nodule and increasing PSA. Increasing prostate volume and a prior negative biopsy were “protective” against having a positive biopsy. The area under the curves (AUCs) for prostate volume, TRUS nodule, and DRE nodule were all superior to PSA for predicting CaP. The ERSPC-RC performed best, followed by the PCPT-RC and then PSA. In the prediction range below 20%, there were only 31 patients with PCPT-RC compared with 480 for the ERSPC-RC. Regarding the avoidance of unnecessary biopsies, the ERSPC-RC was better in the under 30% risk range and similar to PCPT-RC in the above 30% risk range.
Trottier G, Roobol MJ, Lawrentschuk N, Boström PJ, Fernandes KA, Finelli A, Chadwick K, Evans A, van der Kwast TH, Toi A, Zlotta AR, Fleshner NE
BJU Int. 2011 Apr 20. Epub ahead of print.