Necessity of repeat biopsy in suspected prostate cancer: Gen-Probe's PROGENSA PCA3 assay can help determine

Gen-Probe's (Nasdaq: GPRO) PROGENSA® PCA3 assay can help determine whether men suspected of having prostate cancer should undergo a repeat biopsy, according to data from the two largest studies to date of the molecular urine test.  The studies were presented last week at the American Society of Clinical Oncology's (ASCO) Genitourinary (GU) Cancers Symposium in San Francisco.

"These two studies, which involved more than 2,400 men, are the most significant conducted thus far of our PROGENSA PCA3 molecular urine test, and confirm the assay's ability to predict the outcome of a repeat prostate biopsy, thereby helping physicians provide more appropriate, personalized patient care," said Eric Lai, PhD, Gen-Probe's senior vice president of research and development.  

In the studies presented at the ASCO GU meeting, PCA3 was used to test urine samples from men enrolled in the REDUCE trial of GlaxoSmithKline's drug dutasteride.  PCA3 testing was done on urine samples from 1,140 men in the placebo arm of the REDUCE trial, and from 1,308 men in the dutasteride arm.  All men underwent prostate biopsies two and four years after enrollment.

The first PCA3 study presented at the meeting originated from the placebo arm of the REDUCE trial.  This study, which was highlighted in ASCO's official press program, showed that PCA3 scores were significantly correlated with a positive prostate biopsy result (P<0.0001), and that men who had higher PCA3 scores were more likely to have prostate cancer.  Specifically, cancer was diagnosed in only 6% of men with very low PCA3 scores, but in 57% of men with very high PCA3 scores.

PCA3 scores also correlated with cancer aggressiveness: median PCA3 scores were higher in men with high-grade cancers than in those with low-grade cancers>

The second PCA3 study presented at the ASCO GU meeting originated from the dutasteride arm of the REDUCE trial.  This study, which was selected for oral presentation at the meeting, showed that PCA3 also can be used to predict prostate biopsy outcomes in men taking dutasteride.  In contrast to serum PSA testing, median PCA3 scores were equivalent in the placebo and dutasteride groups, and PCA3 sensitivity and specificity were also similar between the two groups.

The second study also confirmed earlier research that showed PCA3 outperforms serum PSA testing for prostate cancer detection, and improves diagnostic accuracy when combined with serum PSA testing and other clinical information.

SOURCE Gen-Probe Incorporated