PRostate Evaluation for Clinically Important Disease: Sampling Using Image-guidance Or Not? (PRECISION)

Official Title

A Randomized Control Trial of Magnetic Resonance Imaging-targeted Biopsy Compared to Standard Trans-rectal Ultrasound Guided Biopsy for the Diagnosis of Prostate Cancer in Men Without Prior Biopsy


This evaluates the detection rates of prostate cancer by MRI-targeted prostate biopsy compared to standard 12-core trans-rectal ultrasound guided (TRUS) prostate biopsy. Each participant will be randomly allocated to one of the biopsy tests.

We hypothesise that MRI-targeted biopsy will detect no fewer clinically significant cancers than TRUS biopsy but will detect fewer clinically insignificant prostate cancers than TRUS biopsy.

Trial Description

Primary Outcome Measures:

  • Proportion of men with clinically significant detected

Secondary Outcome Measures:

  • Proportion of men in MRI arm who avoid biopsy
  • Proportion of men with MRI score 3, 4 or 5 who have no clinically significant cancer detected
  • Proportion of men who go on to definitive treatment for prostate cancer
  • Cancer core length of the most involved biopsy core (maximum cancer core length)
  • Proportion of men with post-biopsy adverse events
  • EQ-5D-5L Quality of Life scores
  • Proportion of men undergoing Radical prostatectomy who have Gleason grade upgrading
  • Cost per diagnosis of cancer
  • Proportion of men with clinically insignificant detected

The classical pathway for the diagnosis of prostate cancer is trans-rectal ultrasound guided (TRUS) biopsy of the prostate following a raised PSA. This is currently the mainstay for prostate cancer diagnosis in the majority of centres. It has many advantages and can be performed routinely under local anaesthetic in an outpatient setting. However it does have some limitations, including the over-diagnosis of insignificant cancer and the under-diagnosis of significant cancer.

An alternative pathway for the diagnosis of prostate cancer in men with raised prostate specific antigen (PSA) is to perform a multi-parametric MRI to localize cancer and to use this information to influence conduct of a subsequent biopsy, known as an MRI-targeted biopsy. MRI-targeted biopsy has been shown in preliminary studies to detect a similar amount of clinically significant cancer to TRUS-biopsy but may have several advantages, for example in reducing the number of men who require biopsy.

This randomized controlled trial aims to assess the detection rate of clinically significant and clinically insignificant cancer of MRI-targeted biopsy compared to standard 12-core TRUS biopsy in men referred with clinical suspicion of prostate cancer who have had no prior prostate biopsy.

A 'clinically insignificant cancer' is cancer which is unlikely to progress or affect a man's life expectancy and therefore does not warrant treatment. However when diagnosed with insignificant cancer a large proportion of patients request treatment in case a more significant cancer is present. A prostate cancer detection pathway that finds significant cancers while avoiding the diagnosis of insignificant cancer is a major unmet need.

The potential implications of this trial include:

  • A redefining of the prostate cancer diagnostic pathway
  • A reduction in the number of patients undergoing prostate biopsy
  • A reduction in the number of biopsy cores taken per patient
  • A reduction in biopsy-related sepsis, pain and other side effects
  • A reduction in the over-diagnosis of clinically insignificant prostate cancer
  • A reduction of the economic burden of diagnosing and treating prostate cancer

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Canadian Cancer Society

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