Video: Prostate MRI: Do You Need a Random Biopsy? | Off The Cuff with Mark Moyad, MD

Off the Cuff with Mark Moyad, MD, MPH | Transcription

Dr. Moyad: You've got all this advancement in MRI. You have the PI-RADS rating scale. And that then begs the question: Why would anybody get a biopsy without an MRI? So why would somebody allow a biopsy to occur which is a little bit more guesswork. I know there's some obvious cases where you feel something, but why wouldn't you at least get a baseline or at least an MRI to see what's going on before you make the decision to have a biopsy?

Dr. Margolis: There was an article that was published in the New England Journal of Medicine Monday, so hot off the presses, that was organized by the University College London group. It was an international multi-site trial, prospective randomized control trial where men who enrolled had not had a biopsy before and either would get a standard 12 core biopsy with no imaging, so no targeting, or would get an MRI and would only get a biopsy and only of the target if there was a target on the MRI. 

Dr. Moyad: Hmm, this is a timely question! 

Dr. Margolis: And what they found is, the group of men that had the MRI found more significant cancer and less insignificant cancers with far fewer total biopsies than the other group. So, in fact, they ended enrolment early. So, we were one of the sites. They were kind enough to leave me on the article considering we didn't enroll anybody because we had everything set up and we were just about to enroll people—like, oh no. We're done. This is so popular, plus the data are so conclusive that we're done. 

Dr. Moyad: So this is going to take us there? This is a step?

Dr. Margolis: This is a step. 

There were a number of sites from the United States, so the FDA should recognize this as valid. The FDA has difficulty with studies performed only outside of the United States because they don't know if it's going to apply to an American population. But this was performed at many sites across the United States and in Europe and South America. 

Dr. Moyad: Are we moving potentially, again, I'm just here... I don't mind playing devil's advocate either, but are we moving potentially to the day where it'll be highly unusual to go stick a needle in a prostate without an MRI? I know it's still fairly common, but it just... It just seems intuitive. I know there's some catches, but are we moving toward that day? Because it's already reduced the number of biopsies significantly. 

Dr. Margolis: Yes.

Dr. Moyad: And what you're telling me about today and what I'm reading about isthe MRIs ability to tell you where there's significant cancer versus where there's non-significant, and that's great.

Dr. Margolis: Yeah. 

Dr. Moyad: Because we have to admit one thing in medicine that we are also in a generation where we are over-diagnosing cancers that won't kill us. And I could also argue we're under-treating cancers that could kill us. 

Dr. Margolis: Yeah. 

Dr. Moyad: But there's this Tale of Two Cities.

Dr. Margolis: Yep.

Dr. Moyad: So I'm looking for... It seems like we're moving toward that day, am I wrong? We're moving toward the day when you have to get an MRI before you get a biopsy. 

Dr. Margolis: We now know that getting the MRI and getting a targeting biopsy is significantly better than just getting the 12-core untargeted biopsy. So that's clear. That's what the New England Journal article showed us. What we need to refine is, well, are there men that do still need the 12-core biopsy? Is there a subset of men where we found significant cancer where we can say AHA, it's because of, you know, these clinical factors? So, you know, you have an MRI, it's negative (meaning there's no target), don't get any biopsy at all unless you fit this category of clinical factors, and that's where we are right now. So for a man not to consider getting a biopsy at all, that's a valid decision, but he is making it in the face of knowing that there's maybe a 5%, maybe even a 10% chance that we're going to miss significant cancer. Now, that doesn't mean that you just, you know, get lost to follow-up and you never get any imaging or PSA tests. The feeling is, most of the cancers that we're missing are small, and cancer grows slowly, and especially the ones that we don't see because they're more indolent and that this man would come back and get a repeat PSA and if it's getting worse then we repeat the MRI, and then even if we didn't see the cancer on the initial MRI we can see the change where it's getting worse on the new one. That is a new enough paradigm that we just don't have that. That most men will still get the systematic biopsies and will not get an MRI as the only diagnostic test, but Britain is moving towards that paradigm right now. So in Britain, if you have what they call raised PSA, you get an MRI, if there's a target you biopsy that and if there's not, you don't, and end of story. And so what we're going to see from Britain are a number of men that have a negative MRI and a raised PSA and follow-up, and we'll have a much better sense of how do we manage men that choose to go with the new treatment paradigm of MRI, no biopsy if it's negative.