NCCN Updates Prostate Cancer Guidelines

Use of MRI Is a Highlight

Nick Mulcahy

December 03, 2014

The 2015 update of the guidelines for prostate cancer from the National Comprehensive Cancer Network (NCCN) marks the 20th annual edition of the guidance.

The update contains three major changes, which are related to imaging, molecular testing, and the systemic treatment of castration-resistant disease, said James Mohler, MD, who chairs the NCCN panel for prostate cancer, in an interview with Medscape Medical News.

The section on imaging has new recommendations on the use of PET for bone scans and on a type of MRI for the imaging of the gland.

The revisions reflect "newly appreciated uses of imaging," said Dr Mohler, who is from the Roswell Park Cancer Institute in Buffalo, New York.

Multiparametric (mp)MRI "can be used in the staging and characterization of prostate cancer" and "to better risk stratify men who are considering active surveillance," reads the guidance.

mpMRI images are defined as those acquired with at least one more sequence in addition to the anatomic T2-weighted images, such as diffusion-weighted imaging and dynamic contrast images.

"MRI can be an invaluable tool in the overall management of prostate cancer," said Marc B. Garnick, MD, from Beth Israel Deaconess Medical Center in Boston, who is not involved with the NCCN and was asked for comment.

"In my own practice, we often use MRI to more fully stage patients after diagnosis. It is particularly helpful in detecting anterior tumors, high-grade lesions, and hints that there may be either seminal vesicle, extracapsular spread, or both. It can also point out suspicious nodes and, for the rare patient with rectal wall involvement, it can be helpful," he told Medscape Medical News in an email.

 
MRI can be an invaluable tool in the overall management of prostate cancer.
 

The use of mpMRI in active surveillance is especially helpful, added Dr Garnick, who is editor-in-chief of the Harvard Medical School Annual Report on Prostate Diseases.

"MRI staging is a very important staging study for any man who is considering active surveillance, since it can definitely identify so-called anterior tumors than can be missed with prostate needle biopsies," he explained.

Dr Garnick noted that mpMRI can also be used to monitor men on active surveillance, which is a recommendation not in the NCCN guidance.

"Because so many men do not want to undergo multiple prostate needle biopsies as part of their active surveillance programs, I have used MRI restaging as a surrogate...for monitoring men on active surveillance programs," he said.

But Dr Garnick acknowledged that such monitoring has "yet to be validated by level 1 evidence." He anticipates such evidence in the future.

Another prominent expert echoed Dr Garnick's comments about MRI and active surveillance earlier this year. At the American Urological Association (AUA) annual meeting in May, Laurence Klotz, MD, from the University of Toronto, who is a pioneer in the practice of active surveillance, said that mpMRI is a "very, very valuable tool" for monitoring men being watched instead of definitively treated.

Nevertheless, the use of mpMRI in prostate cancer is currently somewhat limited, Dr Garnick added.

"It is obviously very widespread in academic centers, but less so in community hospital settings. It is imperative that the radiologist reading the scan is skilled in these interpretations, which takes a specialized level of expertise," he explained.

But Dr Garnick has come to rely on mpMRI in his practice, especially when making a decision about prostatectomy.

"To me, it would be very difficult to consider surgery as an option for any patient, especially any patient with either a primary or secondary Gleason pattern 4 on biopsy, without an accompanying MRI," he said, explaining that it helps define whether or not the cancer is confined to the gland.

Notably, Dr Garnick recommends that, if possible, clinicians finalize their prostate cancer treatment decision with mpMRI. "Send the patient to a qualified MRI facility with specialized radiology services in reading the scans and have this modality completed" before finalizing treatment decisions, he said.

New Technology for Bone Scan

The update also mentions that men with prostate cancer who undergo a bone scan to search for metastatic disease can now be offered a more sensitive test.

The term bone scan has referred, in the past, to the "conventional 99-technetium bone scan" that uses single photon-emission CT, the update reports.

Now, a "newer technology" that uses 18F-NaF as the tracer for the subsequent PET scan "can be used as a diagnostic staging study," according to the guidance. "PET and hybrid imaging bone scans appear more sensitive than conventional 99-technetium bone scans."

Molecular Testing

In the "initial prostate cancer diagnosis" section, a new footnote "generated a lot of discussion among the panel members," said Dr Mohler.

It states that "men with clinically localized disease could consider use of a tumor-based molecular assay to stratify better risk of adverse pathology at radical prostatectomy or chance of biochemical recurrence or disease-specific mortality after radical prostatectomy."

There are some reservations about molecular tests such as Prolaris (Myriad Genetics) and Oncotype DX (Genomic Health), said Dr Mohler. They are very expensive ($3500 to $4000) and clinical trials — to date only sponsored by companies — have not yet been "truly validated," he said. Although both men and clinicians are enthusiastic about using these tests, the problem is that the "enthusiasm exceeds the data," he added.

At this year's AUA meeting, other experts expressed caution about molecular tests.

Tests such as Prolaris, which use biopsied tissue, have been shown to differentiate men at higher risk for death from prostate cancer from those at lower risk, but have not yet been demonstrated to actually improve outcomes, said Stephen Jones, MD, from the Department of Urology at the Cleveland Clinic.

More research is needed to determine if such tests can provide "meaningful and actionable information," he explained.

Section on Castration-Resistant Disease Completely Revised

There has been a "real reorganization of the algorithm" for castration-resistant prostate cancer, said Dr Mohler. And the guidance for treating advanced disease with systemic therapy has been "completely redone," he added.

The principle driver behind the revision is the bevy of new treatments in this area. A key differentiator of treatments is whether or not a treatment has been shown to be effective in patients with visceral metastases (such as those to the lung or liver), said Dr Mohler.

So the guidance directs clinicians to treatments on the basis of the presence or absence of visceral metastases.

Other major organizations have also published treatment guidance for castration-resistant prostate cancer.

The American Society of Clinical Oncology published their own guidance for this setting earlier this year, and the AUA did so in 2013.

The NCCN Prostate Cancer Guidelines are available on the NCCN website.

Dr Garnick and Dr Mohler have disclosed no relevant financial relationships.

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