The urine test that could save more men from a prostate biopsy

Cancer screenings are important for catching specific cancers in their earliest stages — when it may be most treatable.

For men though, it’s a process fraught with anxiety. PSA screenings are often inaccurate and present false positives that lead to unnecessary and very uncomfortable biopsies.

For these reasons, experts began to weigh the benefits against the potential for harm, including long-term urinary incontinence that can occur when the biopsy requires multiple needle sticks.

But in the time since routine PSA testing fell out of favor as a widespread practice, the number of metastatic prostate cancer cases has risen, with diagnoses increasing from 4 percent to 8 percent between 2003 and 2017

The 5-year survival rate for metastatic prostate cancer is 31 percent, compared with the nearly 100 percent 5-year survival rate for prostate cancer caught in the early stages.

Investigators hope they’ve finally hit on just the right test to set these numbers back…

A new test to reduce the need for biopsy

Researchers at the University of Michigan have created MyProstateScore 2.0 (MPS2), a test that screens for prostate cancer in urine samples. MPS2 seeks out 18 different genes associated with high-grade prostate tumors.

“If you’re negative on this test, it’s almost certain that you don’t have aggressive prostate cancer,” says Dr. Arul Chinnaiyan, a professor at the University of Michigan.

The researchers started with a database of more than 58,000 prostate cancer-associated genes and narrowed it to 54 uniquely overexpressed in cancers classified as Grade Group 2 (GG2) or higher. Prostate cancers are ranked from least (GG1) to most (GG5) dangerous.

Then, they tested those 54 genes against urine samples from 761 men with elevated PSA who were scheduled for biopsy. The effort yielded 18 genes that consistently correlated with high-grade cancer in the biopsy specimens — the same genes MPS2 now tests for.

The MPS2 was validated against more than 800 urine samples and correctly identified 95 percent of GG2 prostate cancers and 99 percent of cancers that were GG3 or higher. When estimates of the prostate’s size (or volume) were incorporated, test accuracy was even higher.

How many of those men could have avoided a painful and unnecessary biopsy if the MPS2 had been used? 41 percent — if the prostate volume was included in the measure — and 37 percent if it wasn’t

With the standard PSA blood test, only 26 percent of biopsies would have been avoided.

They noted that even though MRI scans can also be used to predict whether a prostate tumor is likely to spread, ruling out high-grade cancer with a urine test offers some advantages over MRI.

“This research is very encouraging, since many men in rural areas may not have access to prostate MRI machines or the added sophistication that is needed in interpreting these MRI scans,” says Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center. “A widely available urine test may eventually help provide more precision in determining who should undergo a prostate biopsy, and may also help to assess the probability that a cancer is clinically significant and in need of treatment.”

When to get tested

If you are a Black man, the American Cancer Society’s current recommendation is to discuss prostate cancer testing with your doctor beginning at age 45. All other men should discuss prostate cancer testing with their doctor beginning at age 50.

The Prostate Cancer Foundation (PCF) has slightly different recommendations. They advise beginning testing at age 40 if you have a family history of prostate, breast, ovarian, pancreas or other cancers, are Black, or have known BRCA 1/2 mutations. All other men should begin testing at age 45.

Along with testing, lifestyle factors can cut down on prostate cancer risk…

The Mediterranean Diet is the best place to start according to experts who say men with higher levels of lycopene and selenium in their blood are less likely to be diagnosed with prostate cancer.

You also want to make every effort to maintain a healthy weight. Numerous studies have linked hormones secreted by excess fat cells with aggressive prostate cancer. And belly fat, in particular, has been associated with death from prostate cancer.

Last but not least is exercise — which, even in men diagnosed with prostate cancer, has been shown to act like a roadblock to cancer progression.

And don’t forget to check with your doctor on the availability of the MPS2 urine test.

Sources:

New urine test may help some men with elevated PSA avoid biopsy — Harvard Health Publishing

Development and Validation of an 18-Gene Urine Test for High-Grade Prostate Cancer — JAMA Oncology

Put your love into action. Get screened. — American Cancer Society

Should I Be Screened? — Prostate Cancer Foundation