We are delighted with the announcement of the long awaited PROMIS trial results. These results will lead to a paradigm shift in the way men with suspected prostate cancer are investigated.
Men suspected of having prostate cancer through either a raised PSA or abnormal digital rectal examination would previously have had transrectal ultrasound guided biopsies (TRUS) prior to an MRI examination. If the biopsies were positive then a staging MRI examination would be performed. If negative then further biopsies or an MRI would be performed. The problem with this method is that a raised PSA is not specific for cancer. Furthermore, ultrasound guided biopsy may miss significant tumour or conversely biopsy an area of insignificant tumour that could lead to overtreatment and unnecessary worry.
PROMIS set out to see if performing a multiparametric prostate MRI (MP-MRI) before prostate biopsy could safely exclude significant prostate cancer and avoid the need for biopsy. The study also aimed to find out how accurate prostate biopsy was compared with MRI to detect significant cancers. 561 men recruited from 11 hospitals had multiparametric prostate MRI followed by template prostate mapping biopsies then TRUS biopsies. The template prostate mapping biopsies were taken under general anaesthetic and are considered the gold standard as they give a complete overview of the gland.
The study found that MP-MRI is almost twice as sensitive as TRUS biopsy at detecting cancer and has a negative predictive value of 89%. The study also concluded that MP-MRI could be used as a triage to help decide which men should have a TRUS biopsy. This could reduce the number of men needing biopsy by 25% and almost double the number of significant cancers correctly diagnosed, at the same time as reducing false positive diagnoses by about a third.
Clearly, we need to change the diagnostic pathway to include MP-MRI prior to considering biopsy. To do this we will need more radiologists, more scanners capable of performing these high-quality scans and specialist training of radiologists so that they can interpret them. This will greatly improve prostate cancer diagnosis, avoid unnecessary biopsy and over treatment of tens of thousands of men each year.
Dr Phil Haslam
We are currently developing an online training programme in conjunction with the RCR and prostate cancer UK.
This will be available in the next few months.
Further to this you can attend our advanced MP-MRI course in Plymouth on the 15th March (BOOK HERE) and a further more basic MP-MRI course at the RCR in the autumn.