FDA Approves Urine Test for Repeat Prostate Biopsies
February 15, 2012 — The US Food and Drug Administration (FDA) has approved a urine-based molecular assay (Progensa, Gen-Probe) that helps determine the need for repeat prostate biopsies in men who have had a previous negative biopsy.
The test, which is already approved and marketed in Europe and Canada, detects levels of prostate cancer gene 3 (PCA3), which is overexpressed in "virtually all prostate carcinoma specimens," according to an independent review published last year (Nat Rev Urol. 2011;8:123-124).
The PCA3 assay is indicated for helping to decide whether men 50 years or older who have had 1 or more previous negative prostate biopsy, and "for whom a repeat biopsy would be recommended by a urologist based on the current standard of care," should undergo a repeat biopsy, according to the company.
Such men have been described as having a "PSA dilemma" — that is, an elevated PSA score but negative biopsies.
FDA approval of the PCA3 assay was based on a clinical study that enrolled 495 eligible men at 14 clinical sites. In the study, the PCA3 assay had a negative predictive value of 90%, meaning that a negative result predicted a negative prostate biopsy 90% of the time, according to the company.
The pivotal clinical study of the assay only looked at men who were recommended for repeat biopsy. The assay’s performance has not been established in men for whom a repeat biopsy is not already recommended.
"PCA3 provides direct detection of prostate cancer cells," explained Jack Groskopf, PhD, director of research and development in cancer diagnostics at Gen-Probe, at the 2010 Genitourinary Cancer Symposium.
Unlike PSA, it is not expressed in other prostate disorders, such as prostatitis or benign prostatic hyperplasia, he said at a press conference that covered a study of the assay presented at the meeting.
