Prostate Cancer

Jan 2016

How To Get The Diagnosis Right
MRI Scan Before a Biopsy

Prostate Cancer (PCa) is the commonest male cancer in the UK and second commonest cause of death with 43,000 new cases and 11,000 deaths registered in 20121. Despite unequivocal evidence that PSA based screening programmes are now producing up to a 50% fall in PCa mortality2, no national screening programme exists in the UK on the grounds that the "harms" caused by screening, namely "over-diagnosis" and "over-treatment", outweigh the benefits of lives saved. Is this still true in 2016?

Quickly to deal with the "over-diagnosis" and "over-treatment" question: UK men diagnosed with early, curable PCa are discussed by a multi-disciplinary team (MDT) and offered 3 options - radical surgery, radical radiotherapy or active surveillance. This process is designed to achieve clinical consensus and avoid "over-treatment", now borne out by UK figures confirming the growth of active surveillance for non-aggressive cancer. But how does an MDT reach its decision?

Standard UK practice for men referred to a specialist with a consistently raised PSA is to proceed to a transrectal ultrasound scan and biopsy of the prostate (TRUSB) as an outpatient procedure under local anaesthetic. As well as a significant 2% serious complication risk3 the technique misses about 20% of new cancers and even if positive, may not obtain representative tissue from the most important area of cancer present. If the biopsy is positive, the patient is then referred for an MRI scan of the prostate to ensure that the PCa is confined within the prostate and is thus amenable to the option of radical curative treatment. MRI scans are far more accurate and discriminatory compared with ultrasound scans but can only be done after a six week delay to allow biopsy artefacts to settle down. The latest evidence, published in the British Journal of Urology International,5,6, demonstrates clear advantages to placing the MRI scan ahead of any biopsy (see Box).

Advantages of MRI Before TRUS Biopsy

With the benefits listed in the box the conclusion is clear. If a patient wants the best chance of finding or ruling out clinically significant PCa, he should have an MRI scan before a biopsy. Doing so doubles his chance of getting an accurate diagnosis first time.

With a constant stream of improved diagnostic techniques reported almost every month7,8, this latest MRI paper reports yet another significant enhancement of our diagnostic ability that supports the promotion of PSA based screening to detect prostate cancer at an early and curable stage.

Chris Booth

References

  1. Cancer Research UK, 2015
  2. Hugosson J et al, Lancet Oncol 2010; 11(8), 725-32.
  3. Lundstrom K J et al, J.Urol 2014; 192(4): 1116-22.
  4. Resnick M J, NEJM 2013; 368: 436-45.
  5. Emberton M, BJU Int 2015; 116(6): 837-8.
  6. Borkowetz A et al, BJU Int 2015; 116(6): 873-79.
  7. Boegemann M et al, BJU Int. 2016; 117(1): 72-79
  8. Gaziev G et al, BJU Int. 2016; 117(1): 80-86