PCA3 as a diagnostic marker for prostate cancer: a validation study on a Swedish patient population

Prostate cancer antigen 3 in urine (uPCA3) has been shown to perform better than total prostate-specific antigen in serum (tPSA) to predict prostate cancer (PCa) detection. The aim of this study was to validate the diagnostic precision of uPCA3 in a mixed set of patients with no previous history of PCa, including patients with previous negative biopsies.

The study included 62 men scheduled for prostate biopsy at Skåne University Hospital Malmö, Sweden. Urine samples were obtained according to the Progensa™ uPCA3 assay. Logistic regression and receiver operating characteristic curves were used to test associations between levels of biomarkers and prostate cancer.

According to pathological examination of core needle biopsies, PCa was found in 18 out of 62 patients. A one-step increase in uPCA3 was associated with an increase in the odds of cancer of 1.026 (p = 0.005). Differences in the odds ratio between uPCA3 and tPSA were not statistically significant. A model using both markers did not increase prediction of event. Areas under the curve for uPCA3, tPSA and a model combining uPCA3 and tPSA did not differ significantly. No significant correlation was found between uPCA3 and tPSA or prostate volume.

In this small set of mixed patients uPCA3 alone and tPSA performed equally well as diagnostic markers for PCa. A combination of the two markers did not improve the diagnostic performance. This study does not support a role for the uPCA3 urine test to replace or be added to tPSA in PCa detection.