New Prostate Cancer Specific Assay May Reduce Need For Biopsies Interview with:

Eric A. Klein, MD</strong> Chairman, Glickman Urological and Kidney Institute Cleveland Clinic

Dr. Klein

Eric A. Klein, MD
Chairman, Glickman Urological and Kidney Institute
Cleveland Clinic Which of these results did you find most interesting or surprising?

Response: What’s most interesting is that the IsoPSA assay redefines how PSA is measured, which links it more closely to the underlying biology of cancer. Current assays measure only the concentration of PSA, which can be affected by conditions other than cancer – BPH most commonly, but also infection and inflammation – which limits its diagnostic accuracy for finding cancer. Its been known for several decades that PSA exists in multiple different forms in the bloodstream in patients with prostate cancer.

These novel molecules arise because cancer cells have deranged cellular metabolism that result in the generation of new species of PSA, making their measurement more tightly linked to the presence or absence of cancer and even the presence of high grade cancer (where cellular metabolism is even more disordered).

The IsoPSA assay is the first assay to measure all of these isoforms and thus has better diagnostic accuracy for cancer. Where would you expect IsoPSA eventually to fit in the evaluation of men with possible prostate cancer?

Response: Most likely it will be used initially as a reflex test to determine the need for biopsy in men with worrisome (or “elevated”) total PSA, but it may eventually be used instead of PSA in the screening setting, as a way of following men on active surveillance for disease progression triggering treatment, and in measuring response to specific therapies. More data is needed in each of these clinical scenarios to determine its utility in these settings. What main message would you hope for physicians to take away from this report?

Response: The IsoPSA assay is fundamentally different than current assays that measure PSA – it measures structure that is tightly linked to cancer biology instead of measuring PSA concentration, and it has improved diagnostic accuracy. Its use is likely to reduce the number of biopsies performed and reduce the likelihood that a biopsy will find indolent cancer. What other points, if any, would you like to make?

Response: This is a simple and inexpensive assay that will be easy to add onto existing lab infrastructure. Thank you for your contribution to the community.


Eric A. Klein, Arnon Chait, Jason M. Hafron, Kenneth M. Kernen, Kannan Manickam, Andrew J. Stephenson, Mathew Wagner, Hui Zhu, Aimee Kestranek, Boris Zaslavsky, Mark Stovsky. The Single-parameter, Structure-based IsoPSA Assay Demonstrates Improved Diagnostic Accuracy for Detection of Any Prostate Cancer and High-grade Prostate Cancer Compared to a Concentration-based Assay of Total Prostate-specific Antigen: A Preliminary Repo. European Urology, 2017; DOI: 10.1016/j.eururo.2017.03.025

Note: Content is Not intended as medical advice. Please consult your health care provider regarding your specific medical condition and questions.

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Last Updated on May 17, 2017 by Marie Benz MD FAAD