Investigators evaluate nomograms utilizing serum biomarkers, MRI in prostate cancer

In this video, Rashid Siddiqui, MD, and Eric Li, MD, discuss the background behind the recent Prostate Cancer and Prostatic Diseases paper, “Optimizing detection of clinically significant prostate cancer through nomograms incorporating MRI, clinical features, and advanced serum biomarkers in biopsy naïve men.” Siddiqui and Li are urology residents at Northwestern University Feinberg School of Medicine in Chicago, Illinois.

Transcription:

Siddiqui: With prostate cancer, there's been a lot of discussion about how to optimize detection of cancer because there's a real concern for overdiagnosis and overtreatment. There has been a lot of effort been put in over the past decade in terms of improving the diagnosis of prostate cancer, so we only diagnose what would be called a clinically significant cancer, which in many practices would be described as grade group 2 or higher disease. Most notably, what has really gained traction in most practices is using MRI in the setting of elevated PSA, which in multiple trials has been shown to be quite effective in terms of triaging elevated PSA, and has been shown to reduce biopsy by about 30% in trials. Some investigators are also trying to look at biomarkers and see how that can further help triage elevated PSA, because PSA is highly sensitive, but it's not very specific. One of the biomarkers that we typically use at our institution, which was actually developed here by William J. Catalona [, MD], is the prostate health index [phi]. That's proven to be very effective; on its own, it can reduce about 30% of transrectal biopsies. In our institution, we've been using it for almost a decade. We showed actually, in one of our other papers that was published last year, that over 80% of our patients who come through the door at Northwestern Medicine at least get a phi at baseline as part of their triage. Typically, patients who are above the 27 mark of phi typically end up getting an MRI to further triage elevated PSA, and then decide on the biopsy. We wanted to add another layer into how elevated PSA is currently being looked at and triaged, and so we wanted to combine our use of phi, followed by MRI, as 2 steps before a patient gets to biopsy. In other words, basically, it's combined the power of imaging and biomarkers to risk stratify patients to really optimally diagnose patients with clinically meaningful cancer. We want to minimize our negative biopsies and diagnosis of grade group 1 cancers, because as we all know, no one should be getting treated for grade group 1, for the most part, and any type of cancer causes a lot of anxiety among patients.

Li: The main thing I'll just add is that there have been some risk calculators that either just used clinical variables...PSA, digital rectal exam, etc. And there have been some models that have tried to incorporate prostate MRI previously, but there have not really been any models that incorporate both the advanced serum biomarkers, such as phi, and prostate MRI. And the other thing to just note, with the other calculators, is that they include both patients who are biopsy naive and patients who've had prior negative biopsies. Someone's risk of cancer, if they've had a negative biopsy before, is inherently lower. The goal of our study was to look only at the biopsy-naive setting, incorporating both the advanced biomarkers such as phi, as well as MRI together and see whether that can improve our ability to risk stratify patients, before deciding whether to biopsy.

This transcription was edited for clarity.