Urine Test Detects Aggressive Prostate Cancers

Prostate cancer stands as a significant contributor to cancer-related fatalities among men nationwide. Traditionally, screening for prostate cancer entails a blood test to gauge levels of prostate specific antigen (PSA), a substance generated by the prostate gland. Elevated PSA levels often indicate prostate cancer or certain benign conditions, such as prostate inflammation.

The escalation of PSA levels typically prompts further investigation, potentially including a biopsy. Biopsies involve extracting small tissue samples from various regions of the prostate gland to identify cancer cells. While generally safe, biopsies can induce discomfort and side effects like fever or urinary tract infections. Frequently, biopsies detect slow-progressing prostate cancers necessitating vigilant monitoring rather than immediate treatment.

In pursuit of evading unnecessary biopsies, researchers have been exploring noninvasive methods to differentiate between aggressive cancers requiring treatment and indolent ones not necessitating immediate intervention.

Approximately ten years ago, a research team led by Dr. Arul M. Chinnaiyan of the University of Michigan devised a urine-based test termed MyProstateScore (MPS), which persists in usage. This test relies on two genes often prevalent in the urine of men with prostate cancer, facilitating early detection. However, it fails to distinguish between low-grade and high-grade cancers.

In their recent study, led by Chinnaiyan and Dr. Jeffrey Tosoian of Vanderbilt University, the team endeavored to pinpoint urine-based genes capable of discerning aggressive prostate cancers. Their findings, unveiled on April 18, 2024, in JAMA Oncology, showcased a breakthrough.

The researchers initially scrutinized RNA sequencing data encompassing nearly 59,000 genes, identifying 54 potential markers linked to prostate cancer or specifically to high-grade cancers, all detectable in urine. Subsequent analyses and modeling in 761 patients culminated in a set of 17 genes, alongside a reference gene associated with general prostate tissue, comprising the optimal predictors of high-grade cancers. This amalgamation birthed MyProstateScore 2.0 (MPS2).

Validation ensued by analyzing urine samples from another cohort of 743 men, all subjected to biopsy due to elevated PSA levels. Of these, 20% were diagnosed with high-grade prostate cancer. MPS2 demonstrated an impressive 97% accuracy in ruling out high-grade cancer presence. Comparative analysis with other biomarker tests, including the original MPS, revealed MPS2's superior capability in identifying high-grade cancers. The team estimated that MPS2 could mitigate up to 51% of unnecessary biopsies.

Dr. Tosoian underscores the significance of this advancement, affirming, "In nearly 800 patients with elevated PSA levels, the new test aptly ruled out clinically significant prostate cancer, sparing patients from more invasive procedures like MRI and prostate biopsy, with utmost confidence in diagnostic accuracy."