Emerging from a differential proteomic study of sample pairs of prostate cancer and benign tissue, annexin A3 (ANXA3) was chosen as a potential novel biomarker for the early and non-invasive diagnosis of prostate cancer. We wanted to show or investigate, that:

• ANXA3 can be detected in urine after standard digital rectal examination.
• ANXA3 has better specificities than tPSA, in particular in the grey zone of PSA
• ANXA3 can help avoid unnecessary biopsies
• ANXA3 can in the long run replace PSA as a marker

The aim of this multi centre and double-blinded study was to investigate specificities and sensitivities of early detection of prostate cancer with a new protein biomarker, annexin A3, using urine after digital rectal examination/massage (exprimate urine) in direct comparison to the corresponding measurements of the gold standard, total PSA. The material obtained by this non-invasive procedure was moreover used to determine appropriate cut-off values and optimal fractions (e.g. after centrifugation) and calibrations for quantitative measurements of this novel marker.

Patients (500-750) were (and are) continuously recruited from four clinical centres in Germany (Berlin, Tübingen, Ludwigshafen) and Austria (Innsbruck). The major aspect was:

• Can annexin A3 provide a better specificity than tPSA, in particular in the grey zone of PSA (2-10 ng/ml) and can annexin A3 thus contribute to a significant reduction of invasive transrectal biopsies?

Inclusion Criteria:

• Patients with a histological confirmation of adenocarcinoma of the prostate
• Patients with benign prostatic hyperplasia (confirmed by histology of lance biopsies or TUR-P)

Exclusion Criteria:

• Patients with rectal extirpation
• Patients with renal or bladder tumors