Please click here to submit your abstract to the EAU!

This abstract was presented during the past 22nd Annual EAU Congress, Berlin, 21-24 March 2007
Type:	Poster session
Session:	Prostate cancer: Diagnosis
Date:	Wednesday March 21, 2007 from 12:45 to 14:15
Room:	Room 15A

 

The value of the PCA3 Assay in guiding decision which men with a negative prostate biopsy need immediate repeat biopsy: preliminary European data

Haese, A.¹, Van Poppel, H.², Marberger, M.³, Mulders, P.⁴, Abbou, C.C.⁵, Boccon - Gibod, L.⁶, Stenzl, A.⁷, Huland, H.¹, De La Taille, A.⁵, Schalken, J.<sup>8

1</sup>University Medical Centre Eppendorf, Urology, Hamburg, Germany, ²University Hospital Gasthuisberg, Urology, Leuven, Belgium, ³Medical University of Vienna, Urology, Vienna, Austria, ⁴Radboud University Medical Centre, Urology, Nijmegen, Netherlands, The, ⁵CHU Henri Mondor, Urology, Creteil, France, ⁶Service du Prof. Boccon Gibod, Urology, Paris, France, ⁷Uniklinikum Tübingen, Urology, Tübingen, Germany, ⁸Radboud University Medical Centre, Experimental Urology, Nijmegen, Netherlands, The

Introduction & Objectives:

Early diagnosis of prostate cancer (PCa) relies on digital rectal examination (DRE) and prostate specific antigen (PSA) which can trigger prostate biopsy (PB). However, many men with a chronically elevated serum PSA and/or suspicious DRE have had one or more negative PBs. This group will increase in number as more PBs are done due to lowered serum PSA cut-off values, e.g. from 4.0 ng/mL to 2.5 ng/mL. Knowing that 10-25% of these men have a positive repeat PB, the dilemma is what to do next. PB is not only costly but also induces anxiety, discomfort, pain and complications. Therefore, we need additional tests to reduce the number of unnecessary PBs.
The PCA3 (Prostate Cancer Gene 3) Assay from Gen-Probe is the first gene-based highly PCa-specific test which received a CE Mark and is available now in Europe. Data from 226 American men with a serum PSA ≥ 2.5 ng/mL and ≥ 1 negative biopsy have shown that a PCA3 Score ≥ 35 can be used to select men who have a high probability of PCa upon subsequent PB (specificity 72%, sensitivity 58%). The question is whether this also applies to men managed in clinical practice in Europe.

Material & Methods:

In this prospective, multi-national, multi-centre study, men with a serum PSA ≥ 2.5 ng/mL and 1 or 2 negative PBs who were scheduled for repeat PB were enrolled by 7 centres throughout Europe. The PCA3 and PSA mRNA concentrations were measured in first catch urine collected after DRE (3 strokes per lobe) and the PCA3 Score ([mRNA PCA3] / [mRNA PSA] x 1000) was calculated. The PCA3 Scores were compared to the PB outcomes. To demonstrate a specificity of 75% and sensitivity of 50% within 10% confidence intervals (2-sided) at a P-value of 0.05, a sample size of 97 PB positive and 73 PB negative evaluable men was required. Assuming a positive PB rate of 15% and 10% of non-evaluable men, it was estimated that approximately 730 men have to be enrolled.

Results:

Preliminary data of 43 men were available in October, 2006. The mean serum PSA (± SD) was 8.4 (± 5.0) ng/mL and 6 patients (14%) turned out to have a positive repeat PB. The specificity of the PCA3 Assay (with a cut-off PCA3 Score of 35) was 78% (versus 8% for serum PSA with a cut-off of 4 ng/mL) and sensitivity 67%. Patients with a PCA3 Score ≥ 35 had a 33% probability of having a positive PB; those with a score < 35, only a 6% probability.

Conclusions:

Preliminary data confirm the reported positive PB rate of around 15% and the fact that the PCA3 Assay is highly PCa-specific compared to serum PSA in this patient population. A PCA3 Score cut-off of 35 also seems to be able to aid the decision on which men need immediate repeat PB when managed in clinical practice in Europe.

---

Prior to a congress, you need to log in as an EAU member or as press to access the full abstracts.

EAU members, who did not attend the 24^th Annual EAU Congress in Stockholm and wish to receive an Abstract Book can request a copy here.