Impact of prebiopsy MRI on prostate cancer staging: Results from the Norwegian Prostate Cancer Registry

Erik Skaaheim Haug; Tor Åge Myklebust; Patrick Juliebø-Jones; Lars Anders Rokne Reisæter; Kirsti Aas; Arne Stenrud Berg; Christoph Müller; Bjørn Hofmann; Øystein Størkersen; Kim L Nilsen; Tom Børge Johannesen; Christian Beisland

doi:10.1002/bco2.214

Impact of prebiopsy MRI on prostate cancer staging: Results from the Norwegian Prostate Cancer Registry

BJUI Compass. 2023 Jan 10;4(3):331-338. doi: 10.1002/bco2.214. eCollection 2023 May.

Authors

Erik Skaaheim Haug^{1

2

3}, Tor Åge Myklebust³, Patrick Juliebø-Jones^{4

5}, Lars Anders Rokne Reisæter⁶, Kirsti Aas⁷, Arne Stenrud Berg⁸, Christoph Müller⁹, Bjørn Hofmann^{10

11}, Øystein Størkersen¹², Kim L Nilsen³, Tom Børge Johannesen³, Christian Beisland^{4

5}

Affiliations

¹ Department of Urology Vestfold Hospital Trust Tønsberg Norway.
² Institute of Cancer Genomics and Informatics Oslo University Hospital Oslo Norway.
³ Cancer Registry of Norway Oslo Norway.
⁴ Department of Urology Haukeland University Hospital Bergen Norway.
⁵ Department of Clinical Medicine (K1) University of Bergen Bergen Norway.
⁶ Helse Bergen HF, Department of Radiology Haukeland University Hospital Bergen Norway.
⁷ Department of Urology Oslo University Hospital Oslo Norway.
⁸ Department of Oncology Drammen Hospital Drammen Norway.
⁹ Department of Oncology, Cancer Treatment Centre Sørlandet Hospital Kristiansand Norway.
¹⁰ Department of Health Sciences Norwegian University of Science and Technology Gjøvik Norway.
¹¹ Centre for Medical Ethics University of Oslo Oslo Norway.
¹² Department of Pathology, St. Olavs Hospital Trondheim University Hospital Trondheim Norway.

Abstract

Objectives: The aim of this study is to evaluate the 2015 introduction of prebiopsy magnetic resonance imaging of the prostate (MRI-P) as the standard of care for diagnosing prostate cancer (PCa) by the Norwegian public health care authorities. There were three specific objectives of this study: first, to evaluate the consequences of using different TNM manuals for clinical T-staging (cT-staging) in a national setting; second, to determine if the data reveals that MRI-P based cT-staging is superior to digital rectal examination (DRE)-based cT-staging compared with pathological T-stage (pT-stage) post radical prostatectomy; and third, to assess whether treatment allocations have changed over time.

Materials and methods: All patients registered in the Norwegian Prostate Cancer Registry between 2004 and 2021 were retrieved and 5538 were eligible for inclusion. Concordance between clinical T-stage (cT-stage) and pT-stage was assessed by percentage agreement, Cohen's kappa and Gwet's agreement.

Results: MR visualisation of lesions influences reporting of tumour extension beyond DRE findings. Agreement between cT-stage and pT-stage declined from 2004 to 2009, which coincided with an increase in the percentage being pT3. From 2010, agreement increased, which aligned with changes in cT-staging and the introduction of MRI-P. From 2017, regarding the reporting of cT-DRE and cT-Total (overall cT-stage), agreement diminished for cT-DRE but remained relatively stable (>60%) for cT-Total. Regarding treatment allocation, the study suggests that staging with MRI-P has shifted treatment towards radiotherapy in locally advanced high-risk disease.

Conclusion: Introduction of MRI-P has affected cT-stage reporting. Agreement between cT-stage and pT-stage appears to have improved. This study suggests that use of MRI-P influences treatment decisions in certain patient subgroups.

Keywords: MRI; TNM; diagnosis; outcome; population based; prostate cancer; risk groups; staging; treatment.