AUA 2017 just wrapped up in Boston, MA. On Sunday May, 14, Dr. Karim Marzouk and colleagues from Memorial Sloan Kettering Cancer Center presented a poster titled “Combining 4Kscore and MRI for Prostate Biopsy Decision Making”. The session highlighted the findings from the recently published PROMIS MRI trial, utilizing the multiparameteric MRI (mpMRI) as a follow-up test to the 4Kscore. Please read the full article about the session and study below and see the original post on UroToday.
AUA 2017: Combining 4KScore and MRI for Prostate Biopsy Decision Making
Boston, MA (UroToday.com) At today’s 2017 AUA Annual meeting prostate cancer diagnosis and screening podium session, Dr. Marzouk and colleagues presented their work from Memorial Sloan Kettering Cancer Center assessing the utility of multiparameteric MRI (mpMRI) as a follow-up test to the 4Kscore. As the recently published PROMIS MRI trial demonstrated, 11% of men with a normal MRI will have high-grade disease . Since we have many biomarkers, including imaging modalities, available to clinicians in the pre-biopsy setting, studies delineating appropriate patient specific sequences of tests are important.
In this study, the 4Kscore results from the US prospective validation study were combined with mpMRI data available from the PROMIS study. The author used likelihood ratios for MRI detecting high grade disease from PROMIS (positive and negative likelihood ratio of 1.58 and 0.17, respectively) and applied these ratios to probabilities of 4Kscores. Four unique populations were identified based on a threshold for biopsy of 7.5% risk of high grade disease: (i) men with very low 4Kscore for whom risk would not be <7.5% even with positive MRI, (ii) men with 4Kscores <7.5% whose risk would be ≥7.5% if MRI were positive, (iii) men with 4Kscores ≥7.5% whose risk would be <7.5% if MRI were negative, and (iv) men with high 4Kscores whose risk would remain ≥7.5% even if MRI were negative. In the 4Kscore validation study, 1012 men underwent prostate biopsy 23% were diagnosed with ≥Gleason 7 disease. The range of 4Kscores that could be influenced by the results of MRI included 26% of the population with risk <5% (group 1), 10% with risk 5-7.4% (group 2), 45% with risk 7.5-32% (group 3), and 21% with risk > 32% (group 4). Importantly, the net benefit of using 4Kscores alone was 17.7%, mp-MRI 17.6%, and combined strategies was 18.2%.
In summary, this is an elegant study combining imaging and biomarkers to further delineate who should undergo a biopsy. Using mpMRI in the setting of low-intermediate 4Kscores results in a biopsy strategy with higher net benefit compared to using either modality alone.
See Original article at UroToday