PCA3 Materials & News

Henderson J, Ghani KR, Cook J, Fahey M, Schalken J, Thilagarajah R. J Endourol 2010;24:1821-4

• This small study in men undergoing photoselective vaporization of the prostate (PVP) for lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) suggests that the PCA3 Assay can provide valuable information to help decide which patients with elevated PSA levels after PVP need a prostate biopsy
• PVP is used for the treatment of patients with LUTS/BPH. Some patients present with elevated/rising PSA levels after PVP and it is often uncertain whether a prostate biopsy needs to be performed
• This small prospective pilot study included 50 patients who underwent PVP and had a 10-12 core prostate biopsy because of rising PSA levels (> 0.75 ng/mL/year if the PSA was 4.1-10.0 ng/mL or a doubling time < 2 years) after PVP. 54% of patients had a previous negative biopsy. PCA3 Scores were assessed by means of the Progensa^TM PCA3 Assay; a PCA3 Score ≥ 35 was considered a positive PCA3 Score
• Six (12%) of 50 men had a positive (repeat) biopsy. This low rate may be due to the type of patients included in the study and/or that the rise in PSA levels was due to inflammation of the prostate after PVP instead of prostate cancer
• The mean PCA3 Score was significantly higher in men with a positive biopsy (101.2) vs. those with a negative biopsy (50.8)
• Diagnostic accuracy calculations showed a high negative predictive value (NPV) but a low positive predictive value (PPV) for the PCA3 Assay (Table). The low PPV may be an artefact of the small sample size and/or a reflection of biopsy technique (missed cancers)
• Receiver operating characteristic (ROC) analysis showed a high area under the curve (AUC) of 0.773
• Of the 6 men with PCa, only 1 had a negative PCA3 test (i.e. PCA3 Score < 35, being 22). This man had a Gleason scor 6 cancer with cancer in only 7% of one core
• It was concluded that the initial results of this pilot study suggest that the PCA3 Assay is a valuable test to help decide which patients with elevated PSA levels after PVP need a prostate biopsy. A negative PCA3 Score (< 35) is a good predictor of a negative biopsy. Further large-scale studies are needed to confirm the role of the PCA3 Assay in patients with elevated PSA levels after (minimally invasive) surgery for LUTS/BPH

Editorial comment

This is the first study where the value of PCA3 is evaluated in a patient cohort that was treated by laser to reduce prostate size (BPH patients). The study indicates that PCA3 can reassure the urologist and patient in case PSA rises after the laser treatment.

More information: Article at PubMed