Urine Test May Help Predict Prostate Cancer
Gene Test May Help Eliminate Unnecessary Biopsies, Spot Aggressive Cancers in Men With High PSA Levels
Testing for Prostate Cancer Biomarkers continued...
To increase the accuracy of the test, researchers also looked for another gene, called prostate cancer antigen 3, or PCA3, which is also found in urine.
The two tests together appeared to generate both sensitive and specific results. Sensitive means it’s unlikely that the test would miss a case of cancer. Specific means that the test is unlikely to be positive if cancer isn’t really present.
Based on the levels of PCA3 and TMPRSS2:ERG detected, the men were given numerical scores that were classified as being high, medium, or low.
Those scores were then compared to the biopsy results.
“The men in the highest group have a risk of cancer on biopsy of about 70% and those in the lowest group have a risk of cancer of about 20%,” says Tomlins.
Researchers then narrowed their analysis to see how the urine test scores matched the men’s Gleason score, which helps doctors gauge how aggressive a cancer may be.
“What we’ve found is that your risk of having an aggressive cancer if you’re in the high group is about 40%, and if you’re in the low group, the risk of having an aggressive cancer is only about 7%,” Tomlins says.
The company that developed the test, Gen-Probe, helped to pay for the study, and several authors said they had a personal financial interest in the technology.
“This is great science,” says J. Stephen Jones, MD, chairman of the department of regional urology at the Cleveland Clinic in Ohio.
Now that the researchers have validated the test, further studies in larger, more diverse populations will be important to understand how it is best used.
“The real key is using this or any test to help drive decisions,” says Jones, who was not involved in the research, “If it helps me to know who to biopsy or not biopsy, that’s massively valuable information.”