New England Section of the American Urological Association

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4Kscore and mpMRI, in Combination, Safely Reduces Prostate Biopsy Rates
Stephen M. Zappala, MD1, Sanoj Punen, MD2, Badrinath Konety, MD3, Stefan Czarniecki, MD4, Ali Kasraeian, MD5, Eric Kim, MD6.
1Andover Urology, Andover, MA, 2U Miami, Miami, FL, 3Univ Minnesota, Minneapolis, MN, 4Univ Warsaw, Warsaw, Poland, 5Jacksonville Memorial Hospital, Jacksonville, FL, 6Washington University, St Louis, MO

Introduction and objective: mpMRI and biomarkers have emerged as popular alternatives prior to prostate biopsy (Bx). We investigate a combination of the 4Kscore Test and mpMRI to improve diagnostic performance, and potentially further reduce Bx rates compared to the individual tests alone.
Methods: A retrospective, five-center study of 407 men who underwent a 4Kscore, mpMRI, and Bx. mpMRI results were reported with PIRADS and categorized as low (PIRADS 1-2), intermediate (PIRADS 3) and high (PIRADS 4-5). The 4Kscore Test is reported as a continuous percent probability of diagnosing high-grade GG2 or higher cancer (HG): categorized into low (< 7%), intermediate (8 - 32%), and high (> 33%) risk. The primary endpoints evaluated potential Bx reduction, sensitivity, negative predictive value (NPV), and undetected HG cancers when utilizing Single Test or Combination Test strategies for Bx decision-making. Either test was evaluated independently, versus both tests in sequence. Single Test men were stratified with low risk results, avoiding Bx, and intermediate or high risk ,poceeding to Bx. Combination Test, high-risk patients by the first test would receive a Bx and low risk would not. Intermediate risk patients, the second test would be used for determining if a Bx would occur (Fig. 1).
Results: The study includes 407 men: 114 were discovered with HG cancer. Using 4Kscore or MRI alone, resulted in a 25 - 27% biopsy reduction, with 8 - 12 men having undetected HG. Combination strategies yielded higher specificities, leading to larger biopsy reductions in the range of 38 - 41%, while 11-15 men had an undetected HG. Sensitivity and NPV did not appreciably differ between strategies (Table 1). Similar results were observed in those with a total PSA of 2 - 10 ng/mL and 3 - 10 ng/mL.
Conclusions: 4Kscore Test and mpMRI, in conjunction, enhances prostate Bx decision making could further reduce Bx rates, while improving specificity for high-grade cancer, with minimal changes to NPV and sensitivity.

TestBx Reduction (%)Sensitivity (%)Specificity (%)PPV (%)NPV (%)Undetected GG2+ Ca (vs biopsy all)
4Kscore(Single Test)24.893.031.734.692.18
mpMRI(Single Test)27.089.533.434.389.112
4Kscore = Test 1 mpMRI = Test 2 (Combination Test)41.088.652.642.192.213
mpMRI = Test 1 4Kscore = Test 2 (Combination Test)37.686.847.139.090.215


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