Blood exosomal RNA test to rule out prostate cancer spread to bone

Plasma Exosomal RNA Signature for Predicting PSMA PET-Defined Bone Metastasis in Prostate Cancer: A Prospective, Multicenter Discovery, Development, and Validation Study

This project will try a blood-based exosomal RNA test to see if it can rule out bone metastasis in people with newly diagnosed, treatment‑naïve prostate cancer scheduled for baseline PSMA PET.

Quick facts

• Study type: Observational
• Enrollment: 1000 (estimated)
• Ages: 18 Years and up
• Sex: Male
• Sponsor: Xijing Hospital (Academic / other)
• Drugs / interventions: chemotherapy, radiation
• Locations: 9 sites (Lanzhou, Gansu and 8 other locations)
• Trial ID: NCT07553754 on ClinicalTrials.gov

What this trial studies

This is a prospective, multicenter, four‑phase effort to discover and validate a plasma exosomal RNA signature that could rule out bone metastasis. Phase 1 (n=250) uses high‑throughput sequencing to identify candidate exosomal RNAs, and Phase 2 (n=300) uses ddPCR and machine‑learning methods to build and lock a multi‑RNA predictive model. Phase 3 (n=300) performs independent internal validation in a consecutive cohort reflecting natural disease prevalence, and Phase 4 (n=150) performs external validation across multiple centers enriched for bone metastasis. Baseline treatment‑naïve PSMA PET imaging is used as the reference standard, and blood is collected prior to any prostate biopsy or treatment to avoid confounding.

Who should consider this trial

Good fit: Ideal candidates are adults (≥18) with histologically confirmed prostate cancer who are treatment‑naïve, scheduled for baseline PSMA PET, and able to provide a pre‑treatment blood sample collected before any prostate biopsy.

Not a fit: Patients who have already started prostate cancer treatment, had a biopsy before the blood draw, or cannot undergo baseline PSMA PET are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If successful, the test could let many men avoid costly or radiation‑exposing PSMA PET scans by confidently ruling out bone metastasis using a simple blood draw.

How similar studies have performed: Smaller pilot studies and early liquid‑biopsy work on exosomal RNAs have been promising, but large prospective multicenter validation of a rule‑out signature for bone metastasis is still limited.

Eligibility criteria

Inclusion Criteria

1. Patients with histologically confirmed prostate cancer who are scheduled to undergo baseline PSMA PET imaging.
2. Patients who undergo PSMA PET imaging prior to any prostate cancer-related treatment (including androgen deprivation therapy, radiotherapy, or surgery).
3. Patients who provide blood samples for plasma exosomal RNA analysis collected prior to any treatment AND prior to prostate biopsy (if applicable).

   Whole blood samples (approximately 10 mL) will be collected in EDTA tubes at this specified time point. Samples will be processed within 2 hours to obtain plasma and stored at -80°C until analysis.This timing ensures circulating exosomal RNA profiles reflect tumor biology without biopsy-induced contamination.
4. Patients who are willing to undergo prostate biopsy if clinically indicated (biopsy performed after blood collection).
5. Patients who provide written informed consent to participate in the study.
6. Age ≥18 years.

Exclusion Criteria

1. Patients who have received any prior prostate cancer-related treatment before the baseline PSMA PET scan (including hormonal therapy, radiotherapy, chemotherapy, or surgery).
2. Patients whose blood samples were collected after prostate biopsy.
3. Patients with a history of other active malignancies within the past two years (excluding non-melanoma skin cancer).
4. Patients with inadequate blood sample quality or quantity for exosomal RNA extraction and analysis (e.g., hemolysis, insufficient volume \<8 mL).
5. Patients with severe comorbidities or conditions that, in the judgment of the investigator, could interfere with study compliance or pose significant risk.

Where this trial is running

Lanzhou, Gansu and 8 other locations

• The First Hospital of Lanzhou University — Lanzhou, Gansu, China (Recruiting)
• General Hospital of Ningxia Medical University — Yinchuan, Ningxia, China (Recruiting)
• Weinan Central Hospital — Weinan, Shaanxi, China (Recruiting)
• Xijing Hospital — Xi'an, Shaanxi, China (Recruiting)
• Shaanxi Provincial People's Hospital — Xi'an, Shaanxi, China (Recruiting)
• Xijing 986 Hospital — Xi'an, Shaanxi, China (Recruiting)
• The Second Affiliated Hospital of Shaanxi University of Chinese Medicine — Xianyang, Shaanxi, China (Recruiting)
• Qinghai University Affiliated Hospital — Xining, Shaanxi, China (Recruiting)
• Affiliated Hospital of Yan'an University — Yan’an, Shaanxi, China (Recruiting)

Study contacts

• Study coordinator: Jianhua Jiao, MD.

Conditions Prostate Cancer; Bone Metastasis; PSMA PET; Liquid Biopsy; Exosomal RNA; Biomarker Discovery and Validation; Treament-naive; Predictive Signature