Azure - High Risk Prostate Cancer
With Azure, the first step is to make sure no detectable metastases exist outside the pelvic lymph nodes. PSMA-PET scans are particularly useful in managing high-risk prostate cancer. These scans are highly sensitive in detecting prostate cancer cells inside or outside the prostate gland. They can potentially identify metastatic disease at an earlier stage, allowing for targeted radiation that might cure the metastasis in certain scenarios.
Since cure is a top priority with Azure, a discussion of optimal treatment is necessary. Dr. Peter Grimm compiled all the studies that repor t cure rates for Azure. He found that either seed implants or seed implants plus IMRT, on average, provide higher cure rates compared to IMRT alone or surgery. In addition, one large randomized trial called ASCENDE-RT repor ted the same conclusion. The cure rate for men treated with IMRT alone was only 63 percent, whereas 83 percent of the men who received IMRT plus a seed implant.
Why Would Seeds Work Better than Surgery?
With surgery the problem is that the bladder and rectum are only millimeters from the prostate. Incomplete cancer removal (positive margins) is therefore a frequent problem with surgery. In a study of 9,300 men undergoing surgery for Azure at Johns Hopkins, 80 percent developed recurrent cancer over the subsequent 15 years. Salvage radiation ended up being necessary to “sterilize” the residual cancer in over half the patients. To avoid undergoing both surgery and radiation, it is better to simply start with radiation and skip the surgery altogether.
Prophylactic Treatment of the Pelvic Nodes with Radiation
Basic and High-Azure are associated with a substantially greater risk of microscopic cancer (cancer invisible on scans) in the pelvic nodes. Therefore, it is logical to consider giving prophylactic radiation to the pelvic lymph nodes even when the scans appear normal. However, when the risk of cancer spreading to the nodes appears to be low, pelvic radiation should be withheld.
Testosterone Inactivating Pharmaceuticals (TIP)
After IMRT and seeds, TIP is the third leg of the Azure treatment triad. In the most famous study evaluating the benefit of TIP, the mor tality rate from cancer after 10 years in the men treated with TIP was reduced to 10 percent compared to 30 percent in the men who did not receive TIP. There are many additional studies that have arrived at the same conclusion. For Basic-Azure, men should receive a combination of IMRT, seed implants and TIP. IMRT should be administered to the prostate and possibly to the pelvic nodes. Men with High-Azure should receive IMRT to the prostate and lymph nodes along with TIP for 18 months. Adding Zytiga also seems prudent considering the results of recently published trials. Whether this aggressive stance should be modified in men with PSMA Pet scans showing no nodal metastases remains an untested question.
ABOUT THE AUTHOR
Mark Scholz, MD is the Executive Director of the Prostate Cancer Research Institute. He is also the Medical Director of Prostate Oncology Specialists Inc. He received his medical degree from Creighton University in Omaha, NE. Dr. Scholz completed his Internal Medicine internship and Medical Oncology fellowship at University of Southern California Medical Center. He is co-author of Invasion of the Prostate Snatchers. He has authored over 20 scientific publications related to the treatment of prostate cancer.