Pathological findings of visible and non-visible tumors on multiparametric magnetic resonance imaging (MRI) prior to radical prostatectomy

• Published in: Progrès en urologie (Paris) Vol. 27; no. 10; p. 536
• Main Authors: Rivière, A, Cornud, F, Beuvon, F, Sibony, M, Legmann, P, Barry Delongchamps, N
• Format: Journal Article
• Language: French
• Published: France 01-09-2017
• Subjects: Humans; Image-Guided Biopsy - methods; Magnetic Resonance Imaging - methods; Male; Neoplasm Grading; Prostate - pathology; Prostatectomy - methods; Prostatic Neoplasms - pathology; Prostatic Neoplasms - surgery; Treatment Outcome; Tumeur significative; Cancer de la prostate; Significant tumor; IRM multiparamétrique; Targeted biopsies; Biopsies ciblées; Multiparametric MRI; Prostate cancer
• ISSN: 1166-7087
• DOI: 10.1016/j.purol.2017.07.004

As urologists are questioned about the overtreatment of localized prostate cancer, multiparametric MRI can diagnose significant prostate cancer thanks to targeted biopsies. However, some tumors cannot be detected by MRI. What are the pathological characteristics of those tumors?
We have selected 144 consecutive patients treated with radical prostatectomy for clinically localized prostate cancer diagnosed on systematic and targeted biopsies (Koelis
) according to multiparametric MRI findings. On MRI, each suspicious area was graded according to the PI-RADS score v1.0. On radical prostatectomy specimen, tumor foci with a Gleason score greater than 3+3 and/or a tumor volume greater than 0,5cm
were considered significant. The grade-four tumoral volume was calculated by multiplying the tumoral volume by grade 4 tumoral percentage.
Two hundred and seventy seven tumors were identified. A hundred and thirty nine were non-visible on MRI. They had a significantly lower volume (0.15cm
versus 1.45cm
, P<0.0001) and a Gleason score significantly lower (P<0.0001) than apparent tumors. 17.3% of non-apparent tumors were significant. Moreover, the grade-four tumoral volume of significant non-apparent tumors was significantly lower than that of significant apparent tumors (0.11cm
versus 0.66cm
, P<0.0001).
Non-apparent prostate tumors on multiparametric MRI have a Gleason score, a tumor volume - and consequently - a grade 4 tumor volume significantly lower than apparent tumors.
4.