Advanced Prostate Cancer and Serial ctDNA Analysis

Key Takeaways

• Serial liquid biopsies using ctDNA show how metastatic castration-resistant prostate cancer (mCRPC) changes under treatment pressure.
• Androgen receptor (AR) alterations repeatedly appear across therapies and correlate with poorer outcomes.
• One-time genomic testing at diagnosis may miss critical, treatment-driven molecular shifts.
• Real-time molecular monitoring can support more timely, personalized treatment decisions in advanced prostate cancer.

Advanced Prostate Cancer: Why One-Time Genomic Testing Falls Short

Serial liquid biopsies in advanced prostate cancer are reshaping how clinicians understand resistance and disease behavior. A large real-world study published in Clinical Cancer Research, a journal of the American Association for Cancer Research, shows that metastatic prostate cancer undergoes continuous molecular shifts under therapy. These changes, detectable through circulating tumor DNA (ctDNA), carry direct implications for survival and treatment durability.

What Did Serial ctDNA Monitoring Reveal?

Led by investigators from Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine, and developed at the University of California, San Diego with mentorship from the Moores Cancer Center, this multi-center analysis assessed paired ctDNA samples from over 1,700 patients with mCRPC. Additional collaborators included Scripps Research Institute and Guardant Health.

Samples were collected before treatment initiation and again at treatment discontinuation, a period often associated with disease progression. Across androgen receptor pathway inhibitors (ARPIs), PARP inhibitors, and taxane chemotherapy, mutation burden increased after therapy, highlighting strong selective pressure from modern treatments.

A consistent signal emerged: androgen receptor alterations. AR amplifications and mutations appeared after multiple therapy classes, enabling persistent signaling despite pharmacologic suppression. Clinically, these alterations were linked to shorter overall survival, earlier treatment discontinuation, and faster transition to subsequent therapy, regardless of treatment type.

Advanced Prostate Cancer Resistance Patterns Linked to Androgen Receptor Alterations

Beyond AR changes, the study shed light on resistance to targeted therapies. In PARP inhibitor–treated patients, BRCA reversion mutations restored DNA repair capacity, reducing drug effectiveness. Additional alterations in TP53, EGFR, and PIK3CA reflected increasing genomic instability.

For healthcare professionals, these insights reinforce the value of serial ctDNA testing as a dynamic tool. Unlike archived tissue biopsies, liquid biopsies capture the current molecular state of disease, offering a real-time view of resistance mechanisms as they emerge.

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What Should Clinicians Consider Next?

While observational, the data provide a strong biological rationale for integrating serial liquid biopsies into routine mCRPC management. Continuous molecular monitoring may help clinicians adjust treatment strategies earlier, align patients with appropriate targeted therapies, and inform the development of next-generation AR-directed agents and rational combinations, at the right moment in the disease course.

Source:

University of Miami Miller School of Medicine