He first focused on the use of PET imaging in prostate cancer and showed data that highlighted the recent utilization trends of fluciclovine F18 (Axumin®), and PSMA PET imaging. These have both become much more frequently utilized in the last 3 years, particularly as Axumin imaging is now FDA-approved in the setting of post-treatment biochemical recurrence to detect metastatic and/or locally-recurrent disease with a higher sensitivity than prior imaging modalities. He showed additional data that suggests that the ability of advanced PET imaging to detect “occult” metastatic disease increases with a patient’s biochemically recurrent PSA value. Those with higher PSA values have a higher probability of finding metastatic disease with these advanced imaging techniques.
Feng acknowledges that advanced imaging has produced several achievements in the management of prostate cancer, including better detection of disease that may lead to changes in clinical management of patients, as well as the definition of a new disease state – oligometastatic prostate cancer. There remain some unanswered questions about advanced imaging, however. There is no present data to suggest if improved disease detection leads to improved outcomes. Furthermore, we are still uncertain about the possible clinical benefits of advanced imaging. Finally, the optimal treatment approaches for treating the newly-defined oligometastatic prostate cancer is not yet defined. As more patients undergo these advanced imaging techniques, and as we collect more data about outcomes in prostate cancer, the role of PET imaging in prostate cancer will become better defined.
Dr. Feng also focused on the currently available molecular biomarkers that are presently available. He focused on the three commercially available tests, including Oncotype DX®, 4Kscore, and Prolaris®. He showed data that suggests that the addition of these tests to clinical features can help increase prognostic values, in appropriately selected patients. He notes that at present, these tests are mainly helpful for risk-stratification of patients, but one day may be utilized to help predict treatment responses. Feng carefully defined the difference between a prognostic biomarker, which provides information on outcomes independent of the treatment received, versus a predictive biomarker which specifically identifies response or resistance to a particular therapy. He believes in the future, predictive biomarkers will be evaluated to help tailor therapy for patients based on the genetic and epigenetic mutations driving their prostate cancer. There are several clinical trials that are currently accruing patients that will incorporate the use of these predictive biomarkers to help determine treatment type and intensity, but this data is not yet available.
Dr. Feng concluded that advanced imaging and molecular biomarkers can potentially help personalize therapy for patients with prostate cancer. He feels that as more prognostic and predictive biomarkers are validated, treatment options will be more individualized to each patient to optimize outcomes. He is excited to see the results of the clinical trials incorporating advanced imaging and biomarkers once the data is more mature.
Presented by: Felix Feng, MD, Associate Professor of Radiation Oncology; Urology; and Medicine, Vice Chair for Faculty Development and Director of Translational Research, Department of Radiation Oncology, University of California, San Francisco, California
Written by: Brian Kadow, MD, Society of Urologic Oncology Fellow, Fox Chase Cancer Center at the 2019 American Society of Clinical Oncology Genitourinary Cancers Symposium, (ASCO GU) #GU19, February 14-16, 2019 - San Francisco, CA