Why is there a need for additional diagnostic tests in prostate cancer?
Currently, the early detection of prostate cancer (PCa) relies primarily on serum prostate specific antigen (PSA) level and digital rectal examination (DRE).1 The outcome of both tests can result in a prostate biopsy to confirm the diagnosis of PCa.1 However, each of these measures has shortfalls that may lead to unnecessary biopsies and potentially overdetection and overtreatment of clinically insignificant cancer.1
Serum PSA is a standard tool used in the diagnosis of PCa, but is not PCa specific.1 Elevated PSA levels can also be caused by other prostate conditions such as benign prostatic hyperplasia (BPH) and prostatitis.1 According to international guidelines, PSA testing can be offered to well-informed men with a good performance status and a life expectancy of at least 10-15 years.1,2
DRE is another standard procedure that has a poor positive predictive value (PPV), fair reproducibility and a high inter-examiner variability.1,3-4
A transrectal ultrasound (TRUS) of the prostate is sometimes used to guide a biopsy procedure, or to establish prostate volume and PSA density.2 It is no more accurate at predicting organ-confined disease than DRE.2 It is not recommended for the detection of early-stage prostate cancer.3
A prostate biopsy provides the diagnosis of PCa and is indicated based on risk stratification. However, due to the low PPVs of PSA and DRE, approximately 75% of men will have an unnecessary negative initial biopsy.5 The fear that cancer was missed often leads to repeat biopsies, most of which will also be negative.6 The high number of negative initial and repeat biopsies may increase healthcare costs and diminish patients’ quality of life.7-9 Biopsies can induce anxiety because of the fear of having PCa and they may cause discomfort, pain and complications (e.g., hematuria, hematospermia, rectal bleeding and rarely septicemia).7-9
Addressing Overdiagnosis and Overtreatment
Over the years, widespread PSA testing has led to overdetection and overtreatment of clinically insignificant cancer.1 Because PSA does not reliably distinguish between clinically insignificant and significant cancers, there is a demand for novel biomarkers to address clinical need.10
What is the Progensa® PCA3 assay?
The Progensa PCA3 assay detects PCA3, a prostate-specific mRNA biomarker.11 It uses a simple urine specimen collected after a DRE.11 The Progensa PCA3 assay detects the overexpression of the PCA3 gene, which is highly specific for PCa, urine samples.11 The information provided by the test (the PCA3 score) can be used in conjunction with other clinical information to decide whether a prostate biopsy is needed or can be delayed.11 The Progensa PCA3 assay is FDA approved and CE marked.
Intended Use for FDA approved assay11
The Progensa PCA3 assay is an in vitro nucleic acid amplification test.11 The assay measures the concentration of prostate cancer gene 3 (PCA3) and prostate-specific antigen (PSA) RNA molecules and calculates the ratio of PCA3 RNA molecules to PSA RNA molecules (PCA3 score) in post-DRE, first-catch male urine specimens.11 The Progensa PCA3 assay is indicated for use in conjunction with other patient information to aid in the decision for repeat biopsy in men 50 years of age or older who have had one or more previous negative prostate biopsies and for whom a repeat biopsy would be recommended by a urologist based on current standard of care, before consideration of Progensa PCA3 assay results.11 A PCA3 score < 25 is associated with a decreased likelihood of a positive biopsy.11 Prostatic biopsy is required for diagnosis of cancer.
Warning: The Clinical Study only included men who were recommended by urologists for repeat biopsy. Therefore, the performance of the Progensa PCA3 Assay has not been established in men for whom a repeat biopsy was not already recommended.11