Nonetheless, PSA has low specificity for prostate cancer and may be elevated in patients with benign conditions, which leads to unnecessary biopsies as well as the detection of low-grade cancers, resulting in an exacerbation of healthcare costs and some additional patient morbidity. Approximately 1% of patients require hospitalization following prostate biopsy.2
There exist numerous commercially approved biomarker tests (as well as those currently in development) in order to assist the ‘go or no go’ decision for biopsy patients with elevated PSA and a normal digital rectal exam. Such tests require high sensitivity and Negative Predictive Value for clinically significant cancers (Grade Group[GG] 2/Gleason 3+4 or higher) while at the same time minimizing detection of indolent cancers (Grade Group 1/Gleason 3+3), recognizing that GG 2 involves ongoing debate.
The MiCheck-01 clinical trial was conducted in 12 US centres and investigated the performance of biomarkers for PSA, %free PSA, and the Prostate Health Index (PHI) in a contemporary US cohort. This study indicated that while PHI was superior to the other tests in the detection of prostate cancer, these tests did not differentiate clinically significant cancers from indolent cancers.3 Therefore, there exists a need for evaluation of a biomarker test to detect clinically significant prostate cancer with high sensitivity.
Feedback from interviews with US Urologists indicated a preference for a blood based test rather than a urine based test. The urologists desired a test with high sensitivity (ideally >95%) for clinically significant prostate cancer, with minimal detection of low-grade cancers.
The MiCheck-01 clinical trial cohort was designed to evaluate its proprietary biomarker discovery while analysing a diverse US population. Central pathology of all biopsies was performed. Using this methodology, we used the Luminex analysis platform, to determine both analytes and clinical factors that could assist in differentiating GS3+4 or higher cancers (clinically significant or aggressive) from GS3+3 or no cancer. Our findings were successful in discovering a combination of analytes and clinical factors that differentiated clinically significant cancers from indolent or no cancer with high sensitivity and a very high AUC prediction, and this work was published in 2020.4
In our recent publication,5 we further developed and validated the test on the Roche Cobas clinical chemistry analyser. The test is now available in the US as a laboratory developed test (LDT) from Minomic Inc. and is being reimbursed by CMS.
The MiCheck® Prostate test is an algorithm that combines test results from three blood markers (PSA, free PSA, HE4) and the patient’s digital rectal exam result to give a risk score for the presence of clinically significant cancer. In the MiCheck-01 clinical trial population, the test performance was 95% sensitivity, 50% specificity, and 95.3% NPV in >GS 3+4.
In terms of use, sample collection and shipping kits are provided to the urologist’s practice by Minomic Inc. together with the test requisition form. A standard blood draw is performed, and samples are sent to Minomic Inc. via FedEx. The reported turnaround time is approximately 1 week.
Patient results are reported using a cut-off and a percentage risk score. If a patient is below 5% risk of aggressive prostate cancer, they are classified as “low risk” of clinically significant cancer. If a patient is at greater than or equal to 5% risk, they are classified as “increased risk” of clinically significant cancer. The percentage risk of cancer is provided to assist the patient and urologist in shared decision making regarding a decision to proceed to prostate biopsy. For ongoing research, MiCheck® Prostate is currently being evaluated for potential utility in active surveillance. MiCheck® Prostate has recently been implemented in Australia with a particular focus on utility in PI-RADS 1-3 cancers which can harbor between 18 and 20% of clinically significant cancers.6
Written by: Neal D. Shore,1 Dmitry M. Polikarpov,2 Christopher M. Pieczonka,3 R. Jonathan Henderson,1 James L. Bailen,1 Daniel R. Saltzstein,1 Raoul S. Concepcion,1 Jennifer L. Beebe-Dimmer,4 Julie J. Ruterbusch,4 Rachel A. Levin,5 Sandra Wissmueller,5 Thao Ho Le,5 David A. Gillatt,2 Daniel W. Chan,6 Niantao Deng,5 Jaya Siddireddy,7 Yanling Lu,5 Douglas H. Campbell,5 Bradley J. Walsh5
- CUSP LLC Research Consortium, Annandale, VA.
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia.
- Corporate Director of Research of US Urology Partners and Co-Director of Research of Associated Medical Professionals.
- Barbara Ann Karmanos Cancer Institute and Wayne State University School of Medicine Department of Oncology, Detroit, MI.
- Minomic International Ltd., Sydney, NSW, Australia.
- Center for Biomarker Discovery and Translation, Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD.
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia; Minomic International Ltd., Sydney, NSW, Australia.
- Carlsson, Sigrid V. “Screening and Prevention of Prostate Cancer 2021 (Part 1): Evidence for PSA Screening” May 2021. Accessed Sep 2021. https://grandroundsinurology.com/screening-and-prevention-of-prostate-cancer-2021-part-1-evidence-for-psa-screening/
- Fenton JJ, Weyrich MS, Durbin S, Liu Y, Bang H, Melnikow J. Prostate-Specific Antigen-Based Screening for Prostate Cancer: Evidence Report and Systematic Review for the US Preventive Services Task Force. JAMA. 2018 May 8;319(18):1914-1931. doi: 10.1001/jama.2018.3712. PMID: 29801018.
- Shore et al. 2020. A comparison of prostate health index, total PSA, %free PSA, and proPSA in a contemporary US population—The MiCheck-01 prospective trial. Urologic Oncology: Seminars and Original Investigations 38 (2020) 683.e1−683.e10. https://doi.org/10.1016/j.urolonc.2020.03.011
- Shore et al 2020. Development and evaluation of the MiCheck test for aggressive prostate cancer. Urologic Oncology: Seminars and Original Investigations 38 (2020) 683.e11−683.e18. https://doi.org/10.1016/j.urolonc.2020.03.010
- Shore et al 2023. Development and evaluation of the MiCheck® Prostate test for clinically significant prostate cancer. Urologic Oncology 2023 Sep 19:S1078-1439(23)00265-X. doi: 101016/j.urolonc.2023.08.005.Online ahead of print.
- Gillatt et al 2023. Validation of MiCheck® Prostate for significant prostate cancer in an Australian population. British Journal of Urology International, 131, S1 https://doi.org/10.1111/bju.15962