“For the last 40 years the prostate’s been unusual in that we’ve been interrogating men who were at risk of prostate cancer with a random needle deployment of the organ, which we don’t do in any other organ systems in relation to cancer. I think we always knew it was unreliable, and that the diagnosis was uncertain, but I think we just didn’t realize to what degree it was.” Mark Emberton, MD, FRCS
Dr. Mark Emberton is a Professor of Interventional Oncology, Division of Surgery and Interventional Science at University College London. As a Fellow of the Royal College of Surgeons, he is well credentialed. As a leading expert and researcher in prostate cancer, it’s hard to imagine a more renowned and respected leader in his field. By the way, a personal trademark is the neon bright socks he typically wears with his conservative dark suit and tie—though he also often skips the tie.
When he speaks, his cultured British accent and calm academic delivery can be deceptive. If he issues an informed, well-evidenced critique, he is not about to pull punches. The above quote[i] from an interview during the 2018 Congress of the European Society for Medical Oncology (ESMO) is a perfect example. In an understated way, he is actually knocking a cherished idol – the TRUS-guided needle biopsy of the prostate – off its pedestal.
The use of a transrectal ultrasound (TRUS) biopsy has been the gold standard of prostate cancer diagnosis. It is meant to “interrogate” the gland, as he calls it, by systematically but randomly taking 12-14 needle samples from a mental map of gland segments. It is basically random because ultrasound can’t show the difference between normal prostate tissue and cancerous tumors. The doctor has no idea what he’s aiming at. Years ago, I heard one person liken it to sticking a straw in a loaf of rye bread and hoping you pull out a caraway seed.
Three main points
In the brief quote, Dr. Emberton makes three points:
- No other organ cancer is diagnosed by blindly and randomly sampling tissue. This is true for breast, liver, pancreas, brain, kidney, etc.
- TRUS biopsy is unreliable. It may or may not hit cancer. If it does hit cancer, there’s no way to know how much of it there is (tumors can be all shapes, including some rather pancake-shaped while others are more like a ball), or whether you found the most dangerous cells.
- TRUS diagnosis is uncertain. If you don’t know if you missed aggressive cancer, or missed cancer altogether, how can you be sure the diagnosis is accurate?
mpMRI – the game changer
Dr. Emberton is among the researchers who have published evidence that the prostate cancer diagnostic pathway has been revolutionized. As he points out, for the first time in 100 years, we have the imaging ability to identify suspected tumors before we insert a single needle. Multiparametric MRI has “exposed the historical deficiencies in localized prostate cancer diagnosis.”[ii]
There are three “deficiencies” of TRUS biopsy that are concerning, says Emberton. The worst is missing cancer completely, and telling a patient he is cancer-free when he isn’t. The next is missing dangerously aggressive disease (under-diagnosis) and telling a patient he is low-risk when he isn’t. The third is diagnosing insignificant cancer that may never threaten life, and telling a man that he needs immediate radical treatment when he doesn’t.
Multiparametric MRI offers an “ideal pathway” that resolves these three errors by providing “…a vast amount of information that we did not have before. This includes location, volume, multiplicity, and probability.”[iii] In other words, with mpMRI we know where the tumor is, its extent/size, whether there is more than one (multifocal disease), and the likelihood that it is a threat to survival (aggressiveness).
Dr. Emberton presented data from several studies to illustrate the superiority of diagnostic mpMRI-guided biopsy that targets the visible tumor vs. standard TRUS biopsy. In a 2016 prospective study of 233 biopsy-naïve patients randomly assigned to MRI-guided or TRUS biopsy, the detection rates were:
|Overall detection rate||Significant cancer detection rate|
In addition, Dr. Emberton addressed the growing belief that a negative or “clean” mpMRI indicates no need for a biopsy, and the advances in image-guided focal therapy for qualified patients who desire cancer control with minimal-to-no risks of side effects.
Dr. Emberton deserves the respect and gratitude he continues to earn by paving the way for accurate diagnosis and treatment planning through the use of mpMRI.
NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.
[ii] Ibid. “Dr. Emberton Addresses Issues in Diagnosing Localized Prostate Cancer.”
[iii] ESMO 2018: Update on Diagnosis and Treatment of Localized Prostate Cancer. https://www.urotoday.com/conference-highlights/esmo-2018/esmo-2018-prostate-cancer/107809-esmo-2018-update-on-diagnosis-and-treatment-of-localized-prostate-cancer.html