Natalia Rodón1, Isabel Trías1,2,3, Montse Verdú1,2, Ruth Román1, Arturo Domínguez4, Miquel Calvo5, Josep Mª Banus4, Beatriz García-Peláez1, Antonio M Ballesta6, Mª Luisa Maestro7 and Xavier Puig1,2,3.
1 BIOPAT. Biopatologia Molecular SL, Grup Assistència. Barcelona. 2 Histopat Laboratoris, S.L. Barcelona. 3 Hospital de Barcelona, SCIAS, Grup Assistència, Barcelona. 4 ICUN, Institut Català d’Urologia I Nefrologia, Barcelona. 5 Departamento de Estadística. Facultad de Biología, Universidad de Barcelona. 6 Analiza. S. Análisis Clínicos. Hospital Moncloa, Madrid. 7 Unidad de Genómica y Reproducción Asistida, Hospital Clínico Universitario San Carlos, Madrid.
Background: PCA3 gene is a molecular biomarker recently incorporated to clinical practice with specificity close to 80% for prostate cancer (PC) diagnosis. It is currently used as a new diagnostic tool in the clinical management of patients with elevated PSA. PCA3 study in urine collected after prostatic massage significantly reduces the number of prostate biopsies and increases diagnostic yield. Recently it has also granted predictive value of tumor grade and stage. The aim of this study was to analyze the relationship between urine PCA3 score (s-PCA3) with Gleason grade and tumor volume in a series of 131 biopsies performed in patients with elevated PSA and positive s-PCA3.
Desing: 750 urine samples collected after prostatic massage, corresponding to 658 patients with elevated PSA, were included. s-PCA3 (ARNmPCA3/ARNmPSAx1000) was determined using Progensa ™ kits. Biopsies were performed in patients with positive s-PCA3 (≥35). Histopathological and immunohistological studies (AMACR, p63 and 34β12) were conducted by two pathologists independently, on serial sections of paraffin embedded tissues. The average number of studied cylinders was 13 per patient, Gleason scores and percentage of affected cylinders were recorded.
Results:s-PCA3 was positive in 43,3% of studied samples. In this group 131 biopsies were performed, incidence of PC or atypical small acinar proliferation was 52,7%, reaching to 67,6% in s-PCA3≥100. There is a statistically significant relationship between s-PCA3 and tumor grade (p =,002). In cases where positive s-PCA3 was lower than 50, only 23% were high grade (Gleason ≥ 7), whereas with s-PCA3 higher than 50, high grade incidence rose to 75,6%. There was a statistically significant relationship between s-PCA3 and the percentage of affected cylinders (p =,023). None of the PC with positive s-PCA3 lower than 50 had more than 33% of the cylinders affected. Both relationships were confirmed by applying the log-linear model that included the three variables.
Conclusions: Including s-PCA3 studies to PC screening allows a significant reduction in the number of biopsies performed (55,1%) and an increase of positive biopsies (52,7%).
s-PCA3 is also an indicator of tumor aggressiveness and provides essential information when making treatment decisions (grade and tumor volume).
Abstract exhibited at the:
103RD ANNUAL MEETING OF THE UNITED STATES AND CANADIAN ACADEMY OF PATHOLOGY SAN DIEGO, MARCH 2014
Abstract in Modern Pathology 2014; 27: 255A.