The long-standing method for prostate cancer screening, the Prostate-Specific Antigen (PSA) blood test, presents a significant challenge. While effective at detecting prostate abnormalities, an elevated PSA level is not specific to cancer, often leading to unnecessary anxiety and subsequent invasive procedures. PSA testing frequently results in the over-detection of slow-growing, low-risk tumors or the performance of biopsies on men who do not have cancer. This created an urgent need for a more accurate, non-invasive tool to better distinguish between men who require immediate follow-up and those who can safely avoid further intervention.
Context and Purpose of MyProstateScore
MyProstateScore (MPS) was developed as a sophisticated risk assessment tool to provide clarity after initial screening. The test is designed for men who have an elevated PSA result or a suspicious finding from a Digital Rectal Examination (DRE) but have not yet undergone a biopsy. It is also useful for men who have had a previous negative biopsy but remain at risk for a repeat procedure. MPS is a proprietary, validated approach, originally developed by researchers at the University of Michigan.
The primary objective of MPS is to move beyond the limitations of PSA alone by quantifying the personalized risk of finding high-grade prostate cancer upon biopsy. High-grade cancer, defined as Grade Group 2 or higher, typically necessitates treatment. By providing a more accurate risk estimate, MPS helps patients and providers make informed decisions about whether a prostate biopsy is warranted.
The Biomarkers and Methodology
The MyProstateScore test is an advanced molecular analysis combining information from a blood test and a urine sample to predict cancer risk. The initial version utilizes three distinct measurements: the patient’s serum PSA level and the expression levels of two specific genes found in the urine. The urine sample is collected shortly after a Digital Rectal Examination (DRE), which helps release prostate cells into the urinary tract for adequate analysis.
The analysis measures the amount of RNA for two biomarkers: Prostate Cancer Antigen 3 (PCA3) and the TMPRSS2:ERG gene fusion (T2:ERG). PCA3 is a non-coding RNA highly specific to prostate tissue, with expression significantly elevated in cancer cells. The T2:ERG gene fusion is a genetic rearrangement present in a large subset of prostate cancers and is strongly associated with aggressive disease.
The test model combines the quantitative results of these two urinary biomarkers with the serum PSA level to generate a single, integrated prediction of risk. This combination provides a more precise assessment than any single marker alone. More recently, the test evolved into MyProstateScore 2.0 (MPS2), which analyzes the expression of 18 different gene transcripts to enhance the accuracy of the risk calculation.
Understanding Your MPS Result
The output of the MyProstateScore test is a straightforward percentage score, typically ranging from 0% to 100%, which quantifies the patient’s personalized risk. This score represents the estimated probability that a subsequent biopsy would detect high-grade prostate cancer (Grade Group 2 or higher). The result focuses on the likelihood of finding a tumor that requires intervention, rather than just the presence of any cancer.
A score in the lower range, such as below 10%, suggests a very low likelihood of having a high-grade tumor. A low-risk result indicates a high negative predictive value, meaning the probability of not finding clinically significant cancer is very high (often 93% to 98%). Conversely, a higher percentage score signals an increased risk of finding a clinically significant tumor, prompting a stronger recommendation for a biopsy.
The interpretation of the score is discussed in the context of the patient’s individual clinical history, including age and family history. For instance, a score of 25% means that 25 out of 100 men with that result will be found to have high-grade cancer if they undergo a biopsy. This personalized risk assessment allows the patient to weigh the benefits and risks of a biopsy based on objective data.
How MPS Informs Biopsy Decisions
The most significant clinical utility of the MyProstateScore test lies in its ability to safely reduce the number of unnecessary prostate biopsies. Historically, many men with elevated PSA levels underwent an invasive biopsy only to find no cancer or only a low-grade, non-aggressive tumor. MPS addresses this by leveraging its high negative predictive value for high-grade disease.
For men whose MPS result falls into the low-risk category, the confidence that they do not harbor a high-grade tumor is high enough to safely defer a biopsy. Studies have shown that utilizing a low MPS threshold can prevent a significant percentage of biopsies that would otherwise have been negative or only found clinically insignificant cancer. Avoiding these procedures reduces the associated risks of infection, bleeding, and pain. By accurately identifying men at low risk, MPS ensures that the more invasive diagnostic step is reserved for those who stand to benefit most from early detection and treatment.