ESOU18: Biopsy or Monitoring Patients with Negative MRI

Amsterdam, The Netherlands ( Dr. Hugosson presented the proposed significance of patients with a negative MRI.  The European Randomized Study of Screening for Prostate Cancer (ERSPC) study demonstrated that 30% of screen detected cancers never surfaced as clinical cancers. When adjusting for death from other causes, this number is even higher. In contrast, 29 men detected by screening had died from the disease in the ERSPC study. That means that 36% of the potentially lethal cancers detected in the screening program were detected too late, despite the intense screening protocol.

The problem with prostate biopsies, is the fact that they are blind, causing us to miss significant cancers and accidentally diagnose non-significant cancers. This is exactly where the prostate MRI can help us. MRI targeted biopsies can improve detection of clinically significant cancers (90% sensitivity), especially in the anterior aspect of the prostate. It can also decrease the detection rate of non-significant cancers.

There is a methodological dilemma in choosing the correct endpoint when using MRI guided biopsies.  Should we use negative predicted value?  Area under the curve? Sensitivity? All cancer or clinically significant cancers only? Also, choosing the best reference test is also problematic. Should we use systemic biopsies? template saturation biopsies? Or the final prostatectomy specimen. 

In summary, while MRI detects 80-90% of significant cancers, missed cancers are often small high grade cancers. We still have no data regarding the significance of delaying diagnosis in MRI negative cancers. Lastly, it is important to remember that most studies involve centers with experienced radiologists in reading prostate MRI, and this might be significantly different in the community, in non-academic hospitals.

Speaker: Jonas Hugosson, MD Professor and Chief Physician Department of Urology at Institute of Clinical Sciences, University of Gothenburg, Gothenburg, Sweden

Written By: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan at The 15th Meeting of the EAU Section of Oncological Urology ESOU18 - January 26-28, 2018 - Amsterdam, The Netherlands