Urine test better than MRI for monitoring low-risk prostate cancer in new study

A new urine test performed better than PSA-based testing and MRI for monitoring low-risk prostate cancers on active surveillance. Use of the test to determine the need for repeat “monitoring” biopsies would have avoided up to 64% of unnecessary biopsies while maintaining timely detection of higher-grade cancers that merit treatment, according to a study published in The Journal of Urology.

The test, called MyProstateScore 2.0 - Active Surveillance (MPS2-AS), was evaluated in over 300 patients on active surveillance for Grade Group (GG) 1 prostate cancer, according to lead author Jeffrey Tosoian, MD, MPH, assistant professor in the Department of Urology at Vanderbilt Health.

“For patients undergoing monitoring of low-grade prostate cancer, these findings suggest that use of the urine test can reduce the need for invasive biopsies without compromising prompt detection of higher-grade cancers that require treatment,” Tosoian said.

Active surveillance is widely used in men with low-risk prostate cancer to avoid unnecessary treatment of cancers unlikely to cause harm. Because some patients will later be found to “upgrade” to higher-risk cancers, however, surveillance entails careful monitoring. Due to the limitations of existing tools, the current approach to surveillance requires repeat prostate biopsies, usually every two to three years. The urine test offers a noninvasive option to determine which patients truly need to undergo a biopsy and which can avoid a potentially unnecessary and invasive procedure.

Other noninvasive tests have been studied in active surveillance, but none have had sufficient accuracy to rule out the need for repeat biopsies. Tosoian said the study team is optimistic that these findings reflect a significant step forward for the field, and, most importantly, for patients. 

Prostate cancer grading uses the Gleason score (6-10) and Grade Group (1-5) systems to estimate cancer aggressiveness based on how the cells look under a microscope. Higher numbers indicate faster-growing, more aggressive cancer.

In patients previously diagnosed with low-grade cancers (Gleason score 6, Grade Group 1) pursuing active surveillance, MPS2-AS correctly predicted the presence of high-grade (GG≥3) cancer in 97% of cases. The test was found to have a 99% negative predictive value for GG≥3 upgrading, meaning that patients with a negative test had only a 1% chance of having GG≥3 cancer detected on biopsy. For the vast majority of patients, that is low enough to confidently forgo the biopsy altogether, Tosoian said.

Tosoian, also the director of Translational Cancer Research in the Department of Urology, said next steps for the collaborative research team will include studying the use of this testing approach to improve other aspects of prostate cancer care, such as detecting recurrence after treatment.

The study was supported by the National Institutes of Health (grant U2CCA271854).