Mark Emberton, MD
Both the diagnosis and treatment of patients with localized prostate cancer have recently been re-evaluated in an effort to address overtreatment. According to Mark Emberton, MD, FRCS, the most important factor for diagnosis is location, as it provides information to help decide how soon to treat or whether active treatment is necessary.
“Before you stick a needle in the organ, ask the question, ‘Where is the cancer?’ Just asking that question provides those extraordinary benefits,” Emberton said. “This is not a 10% or even 20% difference. This is a 100% difference in detection rates, which is lowering the risk of insignificant disease.”
In an interview with OncLive
, Emberton, professor of Interventional Oncology, Division of Surgery and Interventional Science, University College London, clinical director, Clinical Effectiveness Unit, Royal College of Surgeons of England, discussed updates in the diagnosis and treatment of patients with localized prostate cancer.
OncLive: How has the diagnosis of localized prostate cancer evolved over the last few decades?
It hasn't been a good story, actually. For the last 40 years, the prostate has been unusual in that we have been [testing] men at risk of developing prostate cancer with a random needle deployment of the organ, which we don't do in organ systems in relation to cancer. I think we always knew that it is was unreliable and the diagnosis was uncertain, but I don't think we realized to what degree.
In the last 10 years, the role of imaging has been addressed, and has provided us with location for the first time in the last 100 years. This exposed the deficiencies that we had to live with historically. The worse deficiency was missed cancers, so we told people they were clear when they were not. The second worse deficiency was misdiagnosed cancers, and the third was diagnosing men with low-risk disease, which is an overdiagnosis.
The ideal pathway would correct all of those errors. This analysis discusses the degree to which deriving locations has helped us resolve those errors. In summary, it doubles the risk of detecting clinically significant prostate cancer, which is astounding. Over the last 10 years or more, we have been missing half of the men with clinically significant disease, so it is not surprising that many of our treatments don't work. We also will mitigate the problem of overdiagnosis to a large degree.
Has a focus on multidisciplinary care helped in this communication?
There is no question that bringing in a mixed set of skills to a task results in benefit. It is quite interesting to look at my own professional relationships over the last 10 to 20 years. They have not been with other urologists, they are cross-disciplinary. My best friends are radiologists and pathologists because they are the people that I need in order to get the risk stratification right. One reason that we, as a unit, have been successful and able to research and innovate in the space is that we have had a team of superb radiologists that we work with constantly.
They give us a target, we verify the target, and we give them feedback on the validity of that target. The result is that detection rates go up, which means that we biopsy fewer men. The men that we do biopsy are very likely to have cancer. We are now getting up to detection rates of 80%, whereas historically, they have been in the order of 25% to 30%. It just shows how inefficient the system was before.
Going forward, those relationships are going to have to expand, and we are starting to talk to our engineering colleagues and our computational biology colleagues. Interestingly, molecular medicine now with biomarkers is becoming increasingly important. Synthesizing all those bits of information, such as complex imaging data sets with biomarker data sets, is going to be the challenge for the next 10 years.
Considering the history of overtreatment, what is the current treatment of patients with localized prostate cancer?
The beauty of the new diagnostic pathway is that it does most of the work for us. It gets rid of men with low-risk disease; they cease to exist. We resolved the overdiagnosis issue there.
What has happened is that most of the patients who now present will have clinically significant disease. By deriving location, we don't necessarily have to treat them right away. Part of the impulse to treat was to correct the inherent error that we knew existed. If you did not know how much disease was there, by treating it, the risk of undertreatment was avoided. However, the result was overtreatment.