Incorporating multiparametric MRI staging and the new histological Grade Group system improves risk-stratified detection of bone metastasis in prostate cancer

• Published in: British journal of cancer Vol. 115; no. 11; pp. 1285 - 1288
• Main Authors: Thurtle, David, Hsu, Ray C J, Chetan, Madhurima, Lophatananon, Artitaya, Hubbard, Rachel, Gnanapragasam, Vincent J, Barrett, Tristan
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 22-11-2016; Nature Publishing Group
• Subjects: 692/699/67/322/803; 692/699/67/589/466; 692/700/139; 692/700/1421/1628; Biomedical and Life Sciences; Biomedicine; Bone Neoplasms - diagnostic imaging; Bone Neoplasms - secondary; Cancer Research; Contingency tables; Drug Resistance; Epidemiology; Humans; Investigations; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Metastasis; Molecular Medicine; Neoplasm Grading; Oncology; Prostate cancer; Prostatic Neoplasms - pathology; Risk; Scintigraphy; Sensitivity and Specificity; Short Communication; Urology; United Kingdom > UK; United States > US; prostate cancer; bone scintigraphy; risk stratification; MRI; osseous metastasis; tumour staging
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.2016.353

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.