Which Patients Require Prostate Biopsy?
Introducing MiCheck® Prostate, a groundbreaking solution addressing the limitations of PSA testing. With an estimated 18% of individuals in the PSA 4-10 ng/mL range facing a positive biopsy, it becomes evident that PSA alone fails to distinguish between high-grade, aggressive cancers (Gleason score 3+4 or higher) and indolent cancers (Gleason score 3+3).
In a recent study conducted by Shore et al, it was discovered that 45% of patients who underwent biopsy due to elevated PSA levels did not have prostate cancer. Among those who did have prostate cancer, 19% were identified as having indolent cases, while a mere 36% were diagnosed with aggressive cancer.
Clearly, there is a pressing demand for a test that can accurately identify individuals with aggressive prostate cancer, allowing them to benefit from timely and targeted biopsies. MiCheck® Prostate is the answer, providing the necessary tools to precisely identify those patients who require further investigation.
Intended Purpose of MiCheck® Prostate
MiCheck® Prostate is indicated for male subjects being considered by physicians for a prostate biopsy. It is intended to supplement and not replace the significance of other clinical factors or test results which collectively assist the clinical judgement and experience of the urologist in the decision about whether or not to proceed to prostate biopsy. Prostate biopsy is required for the diagnosis of cancer.
MiCheck® Prostate is an algorithm that combines the testing results of three Roche Elecsys serum immunoassays (total prostate-specific antigen (PSA), free PSA and Human Epididymal Protein 4 (HE4)) with the patient’s digital rectal exam (DRE) result. The MiCheck® Prostate algorithm combines these results to calculate a MiCheck® Prostate Percentage Risk Score, provides an indication of the likelihood of the presence of aggressive (i.e. clinically significant) prostate cancer (AgCaP) (Gleason score ≥7) and is called the MiCheck® %Risk of AgCaP.
The test is intended for professional use only. The digital rectal examination (DRE) is performed routinely by a physician as part of the standard clinical practice. The three immunoassays are performed by a single site at the Minomic Inc. CLIA laboratory (Gaithersburg, Maryland) and then entered in combination with the DRE result into the algorithm to calculate MiCheck® Prostate % Risk Score. MiCheck® Prostate test is currently offered as a Laboratory Developed Test (LDT) to urologists and clinicians.
Value of MiCheck® Prostate
MiCheck® Prostate is designed to be used by the urologist to assist in making a joint decision with the patient on whether to proceed to biopsy after an elevated PSA and/or abnormal DRE result.
MiCheck® Prostate has 95% sensitivity and 50% Specificity for the detection of aggressive prostate cancers, with a negative predictive value of 95% for Gleason ≥3+4 and 99% for Gleason ≥4+3 prostate cancers.
An example of how MiCheck® Prostate can assist in clinical decision-making is provided below in Table 1.
Patients A, B and C all presented with equivalent clinical features: increased PSA and normal DRE. All patients underwent biopsy due to elevated PSA.
Prostate biopsy showed that patient A did not have prostate cancer, patient B had aggressive Gleason 4+3 cancer, while patient C had indolent Gleason 3+3 cancer.
Table 1. Clinical characteristics of three patients tested using MiCheck® Prostate
Figure 2. MiCheck® Prostate patient reports for patients A, B and C
The Unmet Need for a Biomarker to Support Imaging
Professor Mark Emberton OBE, University College London, on his study that aims to improve the current prostate specific antigen (PSA)/biopsy risk stratification for prostate cancer (PCa) and develop a new image-based method with biomarkers like the MiCheck® Prostate for determining high/low risk PCa in men.
Expert Opinion on Need for Biomarker Panels in Biopsy Decisions
Neal D. Shore, MD, FACS presented abstract 229 regarding the current need for a more accurate test to identify patients for prostate biopsy at the 2022 ASCO Genitourinary Cancers Symposium.
How to Use MiCheck® Prostate
MiCheck® Prostate is simple to order and similar to ordering a standard PSA test. It requires a standard serum sample and a DRE result. Serum samples can be shipped using standard couriers such as FedEx, and MiCheck® Prostate results are reported to the clinician electronically via Minomic Inc.
The illustration below outlines the process from ordering MiCheck® Prostate to the reporting of the risk score result:
- A patient presents with elevated PSA and the urologist recommends MiCheck® Prostate to assist in the decision to proceed to biopsy.
- A DRE is performed with the DRE result recorded on MiCheck® Prostate Requisition Form.
- Blood serum sample is collected, as per standard protocol for PSA test, see further details in IFU “Specimen Collection and Shipment to Test Site”.
- The serum sample together with MiCheck® Prostate Requisition Form (that includes the DRE result) are sent to the laboratory for measurement of the three biomarkers.
- Results of biomarkers and DRE are calculated using the MiCheck® algorithm to generate a MiCheck® Prostate %Risk Score and Risk Classification which are then incorporated into the Physician’s report.
- The report is sent to the urologist electronically via Minomic Inc.
