PCA3 Materials & News

Whitman EJ, Groskopf J, Ali A, Chen Y, Blase A, Furusato B, Petrovics G, Ibrahim M, Elsamanoudi S, Cullen J, Sesterhenn IA, Brassell S, Rittenhouse H, Srivastava S, McLeod DG. J Urol 2008;180:1975-9

• This study in 72 men with prostate cancer (PCa) shows that the PCA3 Score is a predictor of extracapsular extension and tumour volume in radical prostatectomy specimens.
• This study confirmed that grade migration is common (in 44% of 72 men) and stresses that there is an urgent need for markers that better predict the pathological stage and significance of PCa.
• Patients with extracapsular extension had a statistically significantly higher median PCA3 Score than patients without extracapsular extension (P=0.02; Figure).
• The PCA3 Score was an independent predictor of extracapsular extension on uni-variate (P<0.01) and multi-variate analysis (including biopsy Gleason score and pre-operative prostate specific antigen (PSA) level; P=0.01).
• Receiver Operating Characteristic curve (ROC) analysis for predicting extracapsular extension showed that the area under the curve (AUC) for the PCA3 Score was 0.732. When the PCA3 Score was combined with biopsy Gleason score > 6 and pre-operative PSA level, the ROC AUC increased to 0.90.
• Patients with a prostatectomy tumour volume > 2.0 mL had a statistically significantly higher median PCA3 Score than patients with a tumour volume 0.5-2.0 mL and < 0.5 mL (P=0.01; Figure).
• The PCA3 Score correlated statistically significantly with prostatectomy tumour volume (Spearman correlation coefficient r=0.38; P<0.01).
• The PCA3 Score was an independent predictor of a prostatectomy tumour volume < 0.5 mL on uni-variate analysis (P=0.03) and multi-variate analysis (including clinical stage and pre-operative PSA level; P=0.04).
• It was concluded that the PCA3 Score may provide prognostic information regarding the pathological stage and significance of PCa. In this respect, the PCA3 Score, and specifically its combination with the biopsy Gleason score and pre-operative PSA level, may aid in treatment decisions, i.e. which patients can be managed with active surveillance and which patients need active therapy. However, the results of this study need to be confirmed in larger scale multi-centre studies.

Editorial comment

This study of PCA3 in men before radical prostatectomy showed a correlation of PCA3 with tumour volume and extracapsular extension. It remains noteworthy to see that radical prostatectomy candidates who proved to have intracapsular disease have a median PCA3 Score of 18.7; also those with tumours between 0.5 and 2.0 mL have median PCA3 Scores of 17.5.  Both these figures are far below the 35 cut off. In line with the remarks in the Editorial comments one could suggest that the PCA3 Score must not be seen in terms of positive or negative but rather as a gradation of risk.  The combination of PCA3 with preoperative PSA, biopsy Gleason Score, … will more adequately predict the risk.

More information: Article at PubMed