PSMA PET imaging’s proliferation produces uptick in aggressive treatment for prostate cancer

The proliferation of prostate-specific membrane antigen PET imaging has led to an uptick in aggressive cancer treatment with implications for value-based care, according to new research. 

First approved by the U.S. Food and Drug Administration in 2021, providers have rapidly adopted this clinical innovation, which offers greater accuracy in detecting prostate cancer compared to conventional imaging. However, this paradigm shift has the potential to prompt a cascade of earlier cancer therapies, without corresponding benefit, experts write in JAMA Oncology. 

Researchers recently aimed to better understand how PSMA PET imaging has changed providers’ approach to treatment, sharing their findings Thursday. 

“As PSMA-PET use grows, enhanced detection of previously occult disease stands to increase eligibility for intensified systemic therapies, with implications for cumulative toxic effects and healthcare value,” Michael S. Leapman, MD, MHS, an associate professor of urology with the Yale School of Medicine, and colleagues wrote May 7. 

For their study, researchers used nationwide Blue Cross Blue Shield claims data to pinpoint beneficiaries diagnosed with incident prostate cancer between 2021 and 2023. Study subjects were between the ages of 40 to 89, with the analysis tracking follow-up care through the end of 2024. The primary exposure was receipt of either a PSMA PET or bone scan within six months before or after diagnosis, identified using claims-based procedure codes. 

Among nearly 6,000 BCBS beneficiaries with newly diagnosed advanced prostate cancer, 65% (or 4,312) received a bone scan (a nuclear test used to detect if the disease has spread to the bones). The other 35% (or 1,581), meanwhile, received a PSMA PET scan, with use of the technology increasing rapidly, surpassing bone scans by 2023. Androgen receptor pathway inhibitor therapy—which blocks male hormones from activating receptors that fuel cancer growth—was more frequent among those who received PSMA PET imaging compared to bone scans (16% vs. 8%). 

When adjusting for various mitigating factors, receipt of PSMA PET imaging was tied to 2.4 higher odds of such therapy initiation. This association remained significant among those who received radical prostatectomy. Receipt of any type of systemic therapy was more common for those receiving PSMA PET imaging (50%) versus bone scans (40%). Same for chemotherapy, which was numerically higher for PET-imaged patients (3%) compared to the other group (2%). Patients who underwent PSMA PET imaging were less likely to receive radical prostatectomy (45% vs. 50%) but more likely to undergo primary radiotherapy (48% vs. 40%). They also more frequently received radiotherapy to secondary cancer sites compared to those undergoing bone scans (6% vs. 2%). 

Leapman and colleagues believe theirs is the first national-scale study to find an association between PSMA PET imaging and differences in treatment for advanced prostate cancer. They caution that their study was limited by the lack of clinical data, such as distribution of imaging findings and prostate-specific antigen levels. 

“These findings underscore patterns of clinical management associated with more sensitive cancer imaging. Greater [androgen receptor pathway inhibitor] use is particularly notable given the substantial cost of these agents and absence of explicit evidence supporting long-term benefit of earlier treatment based on molecular imaging rather than conventional imaging definitions,” the authors concluded. 

“Further studies are needed to determine whether earlier treatment based on molecular imaging is associated with improved survival and quality of life,” they added later.