A large international multi-center study has shown that performing an MRI scan as the first step in suspected prostate cancer patients can cut down the need for prostate biopsies in a quarter of the men.
- An international study shows that using an initial MRI scan can reduce the number of prostate cancer patients who need to undergo biopsies by around twenty-eight percent.
- Among the patients who do go in for biopsies after an abnormal MRI, aggressive tumors are detected at curable stages than with the traditional biopsy alone procedure.
- Patients who show a normal MRI can delay or avoid biopsies thus cutting costs in cancer diagnosis.
Choosing the MRI method can also detect more harmful cancers that need treatment.
The study results have been published in the New England Journal of Medicine2.
‘An initial MRI scan to detect prostate cancer reduces the number of invasive prostate biopsies in a quarter of patients; the MRI scan can also detect aggressive tumors better than standard biopsies.’
Magnetic resonance imaging (MRI)
is a non-invasive medical imaging technique that uses strong magnetic fields and radio waves to look into structures inside the human body.
Current Diagnosis of Prostate Cancer
Prostate cancer is currently diagnosed by a method called TRUS (TRansduced UltraSound guided prostate biopsy)
where a probe with a special needle is inserted into the anus in men under local anesthesia. Biopsy samples, totaling 10 to 12 in number are removed from the prostate to be studied.
Although prostate biopsies are the standard diagnosis to identify suspected prostate cancer in men for the first time, the procedure has a lot of drawbacks - including being uncomfortable, costly, causing risk of infection and a chance of missing tumors.
To overcome these shortcomings, scientists investigated a method that involved using an MRI scan as a first step to see if they can avoid the need for biopsy in some patients, or give better diagnostic information where a biopsy is necessary.
PRECISION 1 Study
The study compared standard prostate biopsy to the use of MRI and offered targeted biopsies only to those men who had a suspicious MRI.
In particular, the study aimed to detect the proportion of men who had a clinically significant/harmful prostate cancer that was desirable to find and those who had a clinically insignificant disease that was desirable to avoid. The aggressiveness of the cancer was determined using a grading system known as the Gleason Score
that has a range of 1 to 5. If the biopsy tissue looks like healthy tissue, the score will be low. Most cancers show a score of 3 or higher.
Researchers from 23 centers randomly assigned 500 men into two groups
- Non-MRI group comprised of 248 men who underwent a standard 10-12 core TRUS biopsy
- MRI group consisted of 252 men who underwent an initial MRI scan followed by a targeted biopsy if the MRI showed an abnormality
Results of the study
- Seventy-one men (28%) in the MRI arm of the study avoided the need for a subsequent biopsy
- Of the remaining 72% of men in the MRI arm who needed a biopsy, the researchers detected clinically significant cancer in 95 (38%) of the 252 men. This was higher compared to the 26% of men (64 out of the 248 men) who received only the TRUS biopsy
The study implies that prostate biopsies can be avoided in 250000 men out of a million who commonly undergo the procedure every year in Europe.
Benefits of using initial MRI assessment followed by biopsy
1.Fewer side effects with MRI than with the standard TRUS biopsy
- Due to avoiding biopsy in men without MRI abnormality
- Due to a better indication of the specific area of the prostate that needs to be investigated
2.Cost-effective in the longer run
- Lesser patients undergo biopsies in the first place
- Early diagnosis of harmful cancers
- Avoiding diagnosing harmless cancers
Dr Veeru Kasivisvanathan of University College London and first author of the study said: "In men who need to have investigation for prostate cancer
for the first time, PRECISION shows that using an MRI to identify suspected cancer in the prostate and performing a prostate biopsy targeted to the MRI information, leads to more cancers being diagnosed than the standard way that we have been performing prostate biopsy for the last 25 years."
About Prostate cancer
Prostate cancer is the most common male cancer. There are around 400,000 new cases every year in Europe. The UK alone has 46,000 new cases of prostate cancer every year where the cancer can lead to death in one-fourth of the patients.
- Kasivisvanathan V , Rannikko A S,, Borghi M, Panebianco V, Mynderse L A, Vaarala H M, Briganti A, Budaus L, Hellawell G,Hindley R.G, Roobol, J.M, Eggener S Prostate MRI reveals more treatable cancers, reduces overdiagnosis than standard biopsy , New England Journal of Medicine (2018). DOI: 10.1056/NEJMoa1801993