Novel Assay Detects and Characterizes Even Microscopic Prostate Cancers

A novel, nanotechnology-based scoring assay developed by researchers at Cedars-Sinai Medical Center was able to detect and characterize even microscopic amounts of prostate cancers, according to findings published in the journal Nano Today.

Prostate cancer is the most common cancer among men in the United States and the second most deadly cancer in US men, the authors noted. Thus, identifying new tests and interventions that serve this population is a research priority. The novel blood test is minimally invasive and could potentially help avoid unnecessary treatment and the resulting side effects.

“This research will revolutionize the liquid biopsy in prostate cancer,” Edwin Posadas, MD, medical director of the Urologic Oncology Program and co-director of the Experimental Therapeutics Program in Cedars-Sinai Cancer, stated. “The test is fast, minimally invasive and cost-effective, and opens up a new suite of tools that will help us optimize treatment and quality of life for prostate cancer patients.”

The assay analyzes extracellular vesicles (EV), which are microscopic particles released by cells throughout the body. Posadas and his fellow investigators developed the novel EV Digital Scoring Assay (DSA) to isolate and analyze EVs quickly and accurately. The EV DSA was more efficient than ultracentrifugation and a commercial EV precipitation assay in isolating prostate-cancer­–derived EVs.

Blood samples from 40 patients with prostate cancer were used to assess the EV DSA’s efficacy. The test was able to differentiate between localized prostate cancer and metastatic prostate cancer, even detecting micro-metastases that advanced imaging would not detect. In practice, the EV DSA could help more accurately determine the best treatment method for each patient.

“This would allow many patients to avoid the potential harms of radiation that isn’t targeting their disease, and instead receive systemic therapy that could slow disease progression,” Posadas said.

In addition to the overall efficacy study, researchers performed a retrospective analysis of blood samples taken over time from 3 patients with prostate cancer. The changes in mRNA signatures that the EV DSA identified were associated with clinical behavior over the course of treatment in these patients. One of the patients had received focused radiation treatments that were ineffective.

“At the time he was being treated, I was concerned that he was not benefiting,” Posadas said. “And the test results mirrored his clinical behavior and showed that, indeed, the treatments were not effective because he had micro-metastatic disease.”

Overall, the authors conclude that the EV DSA could potentially help personalize prostate cancer care, avoid unnecessary treatments, and hopefully improve outcomes.

“This type of liquid biopsy, coupled with innovations such as our Molecular Twin initiative, is key to next-generation precision medicine that represents the newest frontier in cancer treatment,” Dan Theodorescu, MD, PhD, director of Cedars-Sinai Cancer and the PHASE ONE Distinguished Chair, said.

Reference

Wang JJ, Sun N, Lee YT, et al. Prostate cancer extracellular vesicle digital scoring assay - a rapid noninvasive approach for quantification of disease-relevant mRNAs. Nano Today. 2023;48:101746. doi:10.1016/j.nantod.2022.101746