"Most of the 200,000 prostate cancers diagnosed each year in the US are slow growing and will remain so, but the three-gene biomarker could take much of the guesswork out of the diagnostic process and ensure that patients are neither overtreated nor undertreated," said study leader Cory Abate-Shen.
"The problem with existing tests is that we cannot identify the small percentage of slow-growing tumors that will eventually become aggressive and spread beyond the prostate," said coauthor Mitchell C. Benson.
The three genes -- FGFR1, PMP22 and CDKN1A -- are particularly affected by cellular senescence, a process known for playing an essential role in tumor suppression and linked to benign prostate legions in mice and humans.
When these three genes are present, the researchers found, the prostate tumors are low risk. Prostate cancers that test negative for these genetic biomarkers are thus deemed potentially aggressive.
The researchers tested the accuracy of their diagnoses against biopsy specimens from 43 patients who were actively monitored over at least ten years.
Each had initially been diagnosed with a low-risk prostate cancer. Fourteen of them later developed advanced prostate cancer. The genetic biomarker test accurately identified each of them.
"The bottom line is that, at least in our preliminary trial, we were able to accurately predict which patients with low-risk prostate cancer would develop advanced prostate cancer and which ones would not," said Abate-Shen.
The researchers plan to evaluate the genetic test in a larger clinical trial.
About 2.5 million men are living with prostate cancer in the United States, and nearly 30,000 are expected to die from it this year.
Although one in six men will be diagnosed with prostate cancer in their lifetime, most do not die from it.