Advanced imaging technology detects undiagnosed metastases in high-risk prostate cancer

A new study led by researchers at the UCLA Health Jonsson Comprehensive Cancer Center shows that many cases of high-risk, non-metastatic, hormone-dependent prostate cancer may be more advanced than previously thought.

The study, published in , found that almost half of high-risk prostate cancer patients previously classified as non-metastatic on conventional imaging actually have metastatic disease when assessed with advanced prostate-specific membrane antigen– positron emission tomography (PSMA-PET) imaging, suggesting that in many cases traditional imaging may underestimate the extent of cancer spread.

“Our study demonstrates the critical role of PSMA-PET in accurately staging prostate cancer, which can significantly impact treatment decisions and outcomes,” said study senior author Jeremie Calais, Ph.D., director of the Ahmanson Translational Theranostics Division Clinical Trials Program and an associate professor in the department in Molecular and Medical Pharmacology from the David Geffen School of Medicine at UCLA.

This advanced imaging technology is playing a key role in redefining the staging of prostate cancer. PSMA-PET imaging uses small amounts of radioactive “tags”, called radiotracers, that bind to prostate cancer cells, making them visible on PET scans. Unlike conventional imaging, which only provides anatomical details, PSMA-PET offers functional imaging that reveals the biological activity of the tumor, which can significantly improve the accuracy of disease staging.

The clinical adoption of PSMA-PET has changed the imaging landscape for prostate cancer, but treatment decisions are often based on clinical trials that have not incorporated this advanced imaging technique into patient selection.

To better understand the advantages of PSMA-PET over conventional imaging, investigators conducted a post hoc retrospective cross-sectional study using data from 182 patients with high-risk recurrent prostate cancer whose disease was presumed to be confined to the prostate and were eligible for the study. EMBARK study.

This clinical trial previously showed that adding enzalutamide, a type of hormone therapy, to androgen deprivation therapy significantly improved metastasis-free survival. However, the study used conventional imaging to classify patients, which researchers said may have underestimated the extent of the disease in some cases.

In the patient cohort, researchers found that PSMA-PET detected tumor metastasis in 46% of patients, even though traditional imaging showed no evidence of tumor spread. Based on PSMA-PET, it was found that 24% of patients had even 5 or more lesions missed on conventional imaging.

We expected that PSMA-PET would detect more suspicious findings compared to conventional imaging. However, the discovery of such a large number of metastatic lesions in a well-defined patient cohort resembling the EMBARK study population, which was intended to include only patients without metastases, was informative.”

Dr. Adrien Holzgreve, visiting professor at the David Geffen School of Medicine and first author of the study

These results challenge the interpretation of previous studies such as the EMBARK trial and support the inclusion of PSMA-PET in patient selection in clinical and trial interventions for prostate cancer in future large industry-sponsored clinical trials. It also highlights the need to re-evaluate treatment strategies and opens the door to potentially curative options for some patients, such as targeted radiation therapy, while raising important questions about incorporating new imaging technologies into standard care.

While the current findings highlight the potential of PSMA-PET, scientists continue to explore its broader applications through additional research. Calais noted that more research is needed to understand its impact on long-term patient outcomes and how it can best guide therapy.

“We have good reason to believe that relying primarily on PSMA-PET results will be helpful,” Holzgreve said. “But more high-quality prospective data would be needed to establish the superiority of PSMA-PET in treatment guidelines in terms of patient outcomes. However, we are confident that PSMA-PET will continue to contribute to advances in prostate cancer staging and lead the way for personalized therapies.”

Ongoing efforts at UCLA include analysis of follow-up data from four UCLA studies to assess how PSMA-PET results influenced treatment decisions and patient outcomes. Additionally, as part of an international consortium examining over 6,000 patients, the team is examining the prognostic value of PSMA-PET.