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AUA 2019: Insights in Prostate Cancer Identification and Management

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Prostate cancer diagnosis and treatment are ever-changing, with new research showcasing different ways to identify and manage patients with the disease. Three new abstracts—highlighting how beta-blockers may impact prostate cancer risk, the advantages and disadvantages of using magnetic resonance imaging (MRI) to monitor men on active surveillance protocols, and the combined role of the Prostate Health Index (PHI) with MRI in prostate cancer detection—were presented at a press briefing at the 2019 American Urological Association (AUA) Annual Meeting.

Atenolol and Incident Low- And Intermediate-Risk Prostate Cancer

The first abstract in the press briefing by Zahlka et al focused on oral beta-blocker medications, which are commonly prescribed for the treatment of a variety of conditions, including high blood pressure and migraines. In this study, researchers conducted a retrospective review of more than 4,182 men who had undergone a biopsy for prostate cancer, including a cohort of 669 men who had taken a beta-blocker medication—either atenolol, metoprolol, or carvedilol—within 1 year of their biopsy, to determine whether an association exists between these medications and incident prostate cancer on biopsy.

Key findings include:

  • Atenolol was associated with a reduction in incident intermediate-risk prostate cancer of approximately 50% compared to men not taking a beta-blocker.
  • Researchers also identified a significant reduction in incident low-risk disease on biopsy in men taking atenolol.

Assessment of MRI Performance in the Canary Prostate Active Surveillance Study

In recent years, multiparametric MRI has emerged as a tool to aid in the detection of prostate cancer. Additionally, it is being used during follow-up for men on active surveillance protocols. This multi-institutional study, published by Liss et al, examined the effectiveness of multiparametric MRI compared to systematic biopsy to detect Gleason grade 2 or higher disease in a cohort of 325 men on active surveillance who underwent a biopsy within 1 year of having a multiparametric MRI .

Key findings include:

  • The negative predictive value of MRI for Gleason grade 2 or greater cancers was 76%, with a false-positive rate of 49%.
  • In a sensitivity analysis of 287 MRIs in 270 men with Gleason grade 1 cancer prior to imaging, biopsy reclassification to Gleason grade 2 was observed in 21% of men with negative MRI and 35% of men with positive MRI.
  • Systemic biopsy performed better than targeted biopsies in identifying higher Gleason grade, suggesting that systematic biopsies should not be omitted in the setting of positive or negative MRI.

Use of the PHI Assay as First-Line Triaging Test

Multiparametric MRI and the Prostate Health Index (PHI) assay, a blood test used to identify prostate cancer and predict the likelihood of disease progression, are growing in their use as tools to detect prostate cancer and improve the accuracy of prostate biopsies. In this study of 289 men published by Gnanapragasam et al using findings from the prospective UK PHI in Refining MRI study, researchers explored whether the PHI test could refine the use of multiparametric MRI in prostate cancer diagnosis.

Key findings include:

  • PHI was an independent predictor of a positive multiparametric MRI and outperformed both multiparametric MRI and prostate-specific antigen density in predicting significant cancer detection.
  • The combination of multiparametric MRI and PHI had the highest predictive value for a significant cancer. Using an initial threshold PHI of 30 as a cutpoint for referrals and biopsying only men with a positive multiparametric MRI would have saved 23% of multiparametric MRIs and biopsies, while only missing a small percentage of significant cancers (6%).

"The field of prostate cancer diagnosis and management is ever-changing, and these studies mark potentially important steps forward in our research," said press briefing moderator Sam Chang, MD, MBA, the Patricia and Rodes Hart Endowed Chair of Urologic Surgery at Vanderbilt University Medical Center. "Although none of the current testing options are perfect, a combination of MRI and markers, like the Prostate Health Index, may represent the best approach to maximize the identification of clinically significant cancer and reduce the number of biopsies."

Disclosure: For full disclosures of the study authors, visit auajournals.org.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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