Incorporating multiparametric MRI staging and the new histological Grade Group system improves risk-stratified detection of bone metastasis in prostate cancer.
BACKGROUND
There remains uncertainty on the need for bone staging in men with intermediate-risk prostate cancer. Current guidelines do not use mpMRI-staging information and rely on historic pathology grading.


METHODS
We investigated the ability of mpMRI and the new Grade Group system to better predict bone metastasis status in a retrospective cohort study of 438 men with prostate cancer undergoing baseline mpMRI and isotope bone scintigraphy (BS).


RESULTS
Including mpMRI-staging information significantly increased the specificity of bone metastasis detection from 3.0% to 24.2% (P<0.01) and sensitivity from 89.2% to 97.3%. The new Grade Group score demonstrated progressive increase in bone metastasis rates (P<0.001). A novel risk-stratification model combining Grade Groups, PSA and mpMRI staging shows promise in predicting bone metastasis and could potentially reduce BS usage by 22.4%-34.7%.


CONCLUSIONS
Incorporating the new Grade Group system and mpMRI staging more accurately identified bone metastatic risk and suggests men with Grade Group ⩽2 and/or without radiological T3 disease could safely avoid routine bone staging.
Academic Urology Group, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK.
David
D
Thurtle
Academic Urology Group, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK.
Ray C J
RC
Hsu
Cambridge University Clinical School, Cambridge CB2 0SP, UK.
Madhurima
M
Chetan
Institute of Population Health, University of Manchester, Manchester M13 9PL, UK.|Division of Health Sciences, Warwick Medical School, Coventry CV4 7AL, UK.
Artitaya
A
Lophatananon
Department of Urology, Cambridge University Hospitals NHS Trust, Cambridge CB2 0QQ, UK.
Rachel
R
Hubbard
Academic Urology Group, Addenbrooke's Hospital, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK.
Vincent J
VJ
Gnanapragasam
Department of Radiology, Cambridge University Hospitals NHS Trust, Cambridge CB2 0QQ, UK.
Tristan
T
Barrett
D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000473:pathology*; D012306:Risk; D012680:Sensitivity and Specificity