Does the use of PSMA PET impact tumor upstaging?
Prostate-specific membrane antigen PET scans have been proven to increase sensitivity in detecting cancer and metastatic progression, and a new risk analysis suggests that the exam will increasingly result in tumor upstaging as well.
Tumor upstaging is not uncommon after patients undergo surgery, but when it occurs prior to surgery it could significantly impact treatment strategies for prostate cancer patients. The emergence of PSMA PET imaging has opened more doors for earlier diagnosis. In a new analysis published in JAMA Network Open [1], experts discussed the growing prevalence of tumor upstaging and how PSMA PET imaging might contribute to that trend, in addition how these findings could impact treatment in comparison to observations made using conventional imaging.
“Current evidence and guidelines recommend radiation therapy with androgen deprivation therapy as the preferred treatment for prostate cancer with node-positive disease detected by conventional imaging,” corresponding author of the paper Jonathan E. Shoag, MD, of Cleveland Medical Center, and colleagues explained. “However, it is unknown whether men with positive nodes detectable by PSMA PET but undetectable by conventional imaging benefit preferentially from radiotherapy.”
The growing use of PSMA PET has increased the rate of positive nodes detected over the last several years, but how will it impact upstaging rates?
To find out, Shoag and colleagues assessed the data of 207,713 patients who underwent radical prostatectomy from 2010 to 2017. Each patient was reported to have clinically localized high-risk disease according to NCCN guidelines. Experts applied the UCLA PSMA Risk Calculator—a validated nomogram that calculates the risk of upstaging—to the data to determine the significance of how PSMA PET scans could alter tumor upstaging.
Based on calculations, from 2010 to 2017, the risk of PSMA PET upstaging rose yearly, starting at 13% in 2010 to 17.6% in 2017. Risk nodal and distant metastatic upstaging increased from 11.7% in 2010 to 15.4% in 2017, and from 3.6% in 2010 to 4.7% in 2017. The experts noted that during this time PSA, T stage and positive cores did not increase, although Gleason grade group 4 and 5 cancers did.
“While upstaging may be secondary to nodal or distant metastatic findings on PSMA PET, the risk of nodal upstaging in particular may affect the decision between surgery and radiation,” the authors suggested, adding that PSMA PET exams could greatly impact treatment decisions for a significant number of patients categorized as high-risk.
More on the research can be found here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.