PCA3 Materials & News

Auprich M, Chun FK-H, Ward JF, Pummer K, Babaian R, Augustin H, Luger F, Gutschi S, Budäus L, Fisch M, Huland H, Graefen M, Haese A. Eur Urol 2011;59:96-105

• This European/US study in 305 men who underwent radical prostatectomy shows that the PCA3 Score is predictive of low tumour volume and pathologically insignificant prostate cancer (PCa) and may as such be an additional tool to select men suitable for active surveillance or focal therapy
• This retrospective, multi-centre study evaluated the relationship between PCA3 and PCa significance in 305 men who had undergone a radical prostatectomy. Tumour volume data were available for 160 men. Pathological confirmed insignificant prostate cancer was defined according to the Epstein criteria: organ-confined disease, tumour volume < 0.5 mL and no Gleason pattern 4/5
• The median PCA3 Score was statistically significantly lower in men with a tumour volume < 0.5 mL vs. ≥ 0.5 mL: 17 vs. 47; P<0.001 (Figure 1)
• PCA3 was a significant predictor of tumour volume in univariate analysis
• The predictive accuracy of PCA3 for predicting tumour volume was high: Area Under the Receiver Operating Characteristic Curve (AUC ROC) was 0.71
• The inclusion of PCA3 in a multivariate model predicting tumour volume (including PSA, biopsy Gleason score and % positive cores) increased the predictive accuracy of the model by 2.4% to 5.5%, depending on the cut-off used
• The median PCA3 Score was statistically significantly lower in men with pathologically insignificant PCa vs. significant PCa: 16 vs. 45; P<0.001 (Figure 2)
• PCA3 was a significant predictor of pathologically insignificant PCa in univariate analysis
• The predictive accuracy of PCA3 for predicting insignificant PCa was high: AUC ROC was 0.75
• The inclusion of PCA3 in a multivariate model predicting insignificant PCa (including biopsy Gleason score and % positive cores) increased the predictive accuracy of the model by 3.0% to3.9%, depending on the cut-off used
• The median PCA3 score was statistically significantly higher in Gleason score ≥ 7 vs. < 7 cancers: 48 vs. 28, P<0.001
• The median PCA3 Score was not a significant predictor of extracapsular extension or seminal vesicle invasion
• It was concluded that this study, in the largest cohort of RP treated patients to date, confirms that the PCA3 Score represents a valuable predictor of low tumour volume and pathologically insignificant? PCa. Combining PCA3 with established risk factors improves the prediction of low volume disease and insignificant PCa. PCA3 could thus be used to guide the selection of men suitable for active surveillance or focal therapy

Figure 1: The median PCA3 Score is statistically significantly lower in men with a low tumour volume vs. high tumour volume

Figure 2: The median PCA3 Score is statistically significantly lower in men with a pathologically insignificant vs. significant PCa (insignificant PCa defined according to Epstein criteria: organ-confined disease, tumour volume < 0.5 mL and no Gleason pattern 4/5)

Editorial comment

This is another report on a large cohort of men that underwent radical surgery. The study underlines that PCA3 Score is significantly lower in indolent disease. Note, however, that one cannot extrapolate that to state that PCA3 is a pure prognostic marker. It is only so, in the sense that it does not lead to the diagnosis of indolent prostate cancer; a good characteristic of a prostate cancer biomarker. Within the group of significant cancers there seems to be no further value of PCA3 to further differentiate significant low risk from significant high risk. That poses the next challenge for the prostate cancer biomarker researchers.

More information: Article at Pubmed