The SRC estimates a man’s risk for any CaP and for high-grade CaP. They used a combination of age, ethnicity, family history of CaP, urinary voiding symptom score, DRE, PSA, and free:total PSA ratio. The study was a prospective, multi-institutional one that evaluated the performance of these two instruments with regard to their ability to predict the presence of CaP and aggressive, high-grade CaP.
Between 2007 and 2009, a total of 2,130 men were accrued who all had prostate biopsies at five Canadian centers. Patients with a PSA >2.6ng/ml or an abnormal DRE were offered a transrectal ultrasound-guided biopsy, but the risk calculators were not used at this point in the decision to biopsy. Biopsies were 10-12 cores. There was no central pathologic review of the biopsies. The significance between AUCs of the risk calculators was tested using 2,000 concordance indices for each model by using bootstrapping analysis and then calculating the differences between the paired concordance indices.
The median PSA level for the 2,130 men was 5.7ng/ml and the median age at biopsy was 63 years. A positive family history was noted in 22% and most men were Caucasian. CaP was found in 867 men (41%) - 1,263 men (59%) had no CaP. Among those with CaP, 54% had Gleason score 6, 27% had Gleason score 7, and 19% had Gleason score 8-10. The AUC for the SRC in predicting CaP was significantly higher (0.67) compared with the PRC (0.61). SRC was also higher for predicting aggressive CaP (0.72) compared with the PRC (0.67). For predicting any CaP, the calculators were comparable with regard to sensitivity, specificity, positive predictive value, and negative predictive value. The SRC was better for sensitivity and negative predictive value for predicting aggressive CaP in the low threshold range.
Nam RK, Kattan MW, Chin JL, Trachtenberg J, Singal R, Rendon R, Klotz LH, Sugar L, Sherman C, Izawa J, Bell D, Stanimirovic A, Venkateswaran V, Diamandis EP, Yu C, Loblaw DA, Narod SA
J Clin Oncol. 2011 Aug 1;29(22):2959-64
10.1200/JCO.2010.32.6371
PubMed Abstract
PMID: 21690464
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