PCA3 IMPROVES DETECTION OF PROSTATE CANCER

NEW YORK (Reuters Health) Aug 25 - Prostate cancer antigen 3 (PCA3) gene score contributes to the diagnosis of prostate cancer, especially in men with serious disease, researchers from the Netherlands report in the July 9th online European Urology.

But on its own, PCA3 testing is "definitely not the solution for the problems that coincide with prostate cancer screening," lead author Dr. Monique J. Roobol from Erasmus MC, University Medical Center, Rotterdam, told Reuters Health by email. "It most likely will be of value in combination with other markers."

Dr. Roobol and her colleagues compared the performance of a PCA3 test with a cut-off score of at least 10 to a PSA threshold of at least 3.0 ng/mL. Their subjects were 965 prescreened men enrolled in the European Randomized Study of Screening for Prostate Cancer study (ERSPC).]

Among the 721 men (74.7%) who had biopsy for one of these cut-off levels, 122 (16.9%) turned out to have prostate cancer.

Most of the biopsy indications were based on PCA3 alone (492 cases); few were based on PSA alone (32 cases).

The PSA cut-off of 3.0 ng/mL correctly identified 35.2% of all prostate cancer cases and 69% of men who did not have prostate cancer.

In comparison, a PCA3 score of at least 20 identified 18 of 19 serious prostate cancer cases and could have avoided 26.1% of biopsies. Raising the cutoff to at least 35 would have missed four serious prostate cancer cases but could have avoided 48.3% of all biopsies.

"Based on the ROC analyses," the researchers note, "PCA3 performs marginally better than PSA."

Where should this test fit in the screening of men for prostate cancer? Dr. Roobol suggested, "Most likely in men with persistent elevated PSA levels and benign biopsy results."

Eur Urol. Posted online July 9, 2010. Abstract