Stockholm3 Test Validation in Men on Active Surveillance in Switzerland (CHAS3 Trial) (CHAS3)

Multicenter Validation of the Stockholm3 Test on Men on Active Surveillance: the CHAS3-Trial

The CHAS3 trial studies whether the Stockholm3 blood test can reliably detect if prostate cancer becomes more aggressive in men who are being carefully monitored instead of treated right away (active surveillance). The goal is to see if this test can help doctors safely follow patients with fewer invasive procedures, such as repeated biopsies.

Study Overview

• Status: Not yet recruiting
• Conditions: Prostate Cancer; Active Surveillance for Prostate Cancer
• Intervention / Treatment: Diagnostic test: Stockholm3

Detailed Description

The CHAS3 trial is a study carried out at several hospitals that follows men with prostate cancer who are being closely monitored through active surveillance. The study looks at how well the Stockholm3 blood test can predict whether the cancer has become more serious when the men later have their scheduled follow-up biopsy.

Men who are already on active surveillance and planned for a routine biopsy may be invited to join. Participants must be alive and must not have started any treatments such as surgery, radiation, hormone therapy, or chemotherapy. To avoid extra procedures, any study samples will be taken at the same time as the patient's regular follow-up visits.

• Study Type: Observational
• Enrollment (Estimated): 350

Contacts and Locations

• Study Contact: Name: Nicola Giudici, Dr.; Phone Number: +41316322332; Email: urologie.studienmanagement@insel.ch
• Study Contact Backup: Name: Anselm Lafita, CRC; Phone Number: +41316322332; Email: anselm.lafita@insel.ch

Study Locations

• Switzerland
  • Canton of Bern
    • Bern, Canton of Bern, Switzerland, 3010
      • Inselspital, University Hospital of Bern
      • Contact: Lafita Anselm, CRC; Phone Number: +41316322332; Email: urologie.studienmanagement@insel.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Male Patients with a prostate cancer diagnose under active surveillance being treated on Swiss Hospitals

Description

Inclusion Criteria:

• Adult Men ≥ 18 y. o.
• Men with low-risk prostate cancer (D'Amico risk classification) currently undergoing Active Surveillance (AS)
• First inclusion in Active Surveillance (AS) after 1st January 2022.
• Scheduled for follow-up with systematic and/or Magnetic Resonance Imaging (MRI)-targeted (fusion) prostate biopsies - Prostate Magnetic Resonance Imaging (MRI) performed within the past three months available

Exclusion Criteria:

• - Prior prostate cancer treatment (surgery, radiation, chemotherapy, hormonal therapy).

  • Patient with intermediate- or high-risk prostate cancer
  • Urinary catheterization within the past 6-8 weeks
  • Contraindications to Magnetic Resonance Imaging (MRI) or biopsy

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Stockolm3 Blood test in prostate cancer patient under active surviellance; Diagnostic procedure	Diagnostic test: Stockholm3; Predictive value of Stockholm3 test in a prostate cancer cohort on Active Surveillance (AS) for upgrading on re-biopsy

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Diagnostic accuracy of the Stockholm3 test for detection of histological upgrading to ISUP Grade Group ≥2 at follow-up prostate biopsy	The Stockholm3 risk score (cutoff ≥11) will be evaluated for its ability to predict histological upgrading to ISUP Grade Group ≥2 at scheduled follow-up prostate biopsy in men undergoing active surveillance for prostate cancer. Diagnostic performance will be quantified using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC).	At time of follow-up biopsy (baseline visit; Day 0 of study procedures)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensitivity and specificity of the Stockholm3 test at predefined risk thresholds (≥11, ≥13, ≥15) for detection of ISUP Grade Group ≥2 prostate cancer	Diagnostic performance of the Stockholm3 test will be evaluated at predefined thresholds using contingency table analysis. Sensitivity, specificity, PPV, NPV, and AUC will be calculated to compare performance across thresholds.	At time of follow-up biopsy (baseline visit)
Comparative diagnostic accuracy of Stockholm3 test versus PSA density, PSA doubling time, and MRI progression for detection of ISUP Grade Group ≥2 upgrading	The predictive performance of Stockholm3 will be compared with PSA density (PSAd ≥0.15), PSA doubling time (<3 years), and MRI progression (PRECISE classification ≥3 or ≥4). Diagnostic accuracy metrics (sensitivity, specificity, PPV, NPV, and AUC) will be calculated and compared between methods.	At time of follow-up biopsy
Change in patient-reported quality-of-life scores measured using the EPIC-26 questionnaire following prostate biopsy	Quality of life will be assessed using the Expanded Prostate Cancer Index Composite-26 (EPIC-26). Domain scores (urinary, bowel, sexual, and hormonal function) will be summarized as mean change from baseline to 4 weeks post-biopsy. Clinically meaningful deterioration will be defined as a decrease of ≥10 points in domain score.	Baseline and 30 days after prostate biopsy

Collaborators and Investigators

• Sponsor: Insel Gruppe AG, University Hospital Bern
• Investigators: Study Chair: Beat Roth, Prof. Dr. med., Inselspital, University Hospital of Bern

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2026
• Primary Completion (Estimated): March 31, 2028
• Study Completion (Estimated): August 31, 2028

Study Registration Dates

• First Submitted: March 12, 2026
• First Submitted That Met QC Criteria: March 12, 2026
• First Posted (Actual): March 17, 2026

Study Record Updates

• Last Update Posted (Actual): March 30, 2026
• Last Update Submitted That Met QC Criteria: March 24, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: MRI; Cancer; Prostate; Active Surveillance; Stockholm3; Biopsie
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Neoplasms, Male; Urogenital Neoplasms; Neoplasms by Site; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Neoplasms; Prostatic Neoplasms
• Other Study ID Numbers: CHAS3-2025-NG-001

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No