Key Clinical Summary: Applying ctDNA Results to Guide Individualized Care

This is a micro-learning module summary of a presentation by Dr. Matthew Galsky which you can find here. Before participating, please read our CME and disclosure information which can be found here.

This program is supported by an independent educational grant from Genentech. This accredited education activity is available to U.S. healthcare professionals only.

Introduction
This summary explores contemporary evidence on circulating tumor DNA (ctDNA)‑guided management of muscle‑invasive urothelial carcinoma (MIBC), outlining how postoperative and serial ctDNA assessments can inform escalation and de‑escalation strategies. It reviews prospective and retrospective data supporting ctDNA as a marker of minimal residual disease, examines the emergence of molecular recurrence as a clinically actionable state, and evaluates how ctDNA kinetics during neoadjuvant therapy provide prognostic insight without influencing postoperative decision‑making within current evidence boundaries.

Interpreting Post‑Cystectomy ctDNA to Guide Escalation and De‑escalation

ctDNA positivity immediately after cystectomy consistently identifies patients with high recurrence risk and a strong likelihood of benefiting from adjuvant immune checkpoint blockade.
Persistently negative ctDNA across serial assessments is associated with excellent prognosis, although this status cannot be known at the time of initial adjuvant decision‑making.
A single negative postoperative ctDNA result does not yet justify withholding adjuvant therapy, as a proportion of initially negative patients later convert to positive.
De‑escalation strategies based on ctDNA negativity remain investigational pending randomized evidence confirming non‑inferiority compared with universal adjuvant treatment.

Prospective Validation of ctDNA‑Guided Treatment: IMvigor011

IMvigor011 prospectively evaluated ctDNA‑guided adjuvant therapy using a tumor‑informed assay.
Patients with detectable ctDNA after cystectomy were randomized to atezolizumab or placebo, demonstrating significant improvements in disease‑free and overall survival with treatment.
Patients who were initially ctDNA‑negative underwent serial monitoring; 22% converted to ctDNA‑positive during the first year.
Conversion from negative to positive ctDNA (molecular recurrence) was clinically actionable, with atezolizumab improving outcomes when initiated at the time of conversion.

Clinical Meaning of Molecular Recurrence

Molecular recurrence represents a new disease state in urothelial cancer, preceding radiographic relapse and enabling earlier therapeutic intervention.
ctDNA conversion in the absence of radiographic disease should be interpreted as molecular recurrence rather than an indeterminate or clinically insignificant finding.
Molecular recurrence warrants treatment escalation with adjuvant immunotherapy based on prospective evidence.
Delaying action until radiographic progression risks missing a window where immunotherapy is most effective.
Repeat cystectomy is not indicated in this scenario, as recurrence is systemic rather than localized.

Persistently Negative ctDNA and the Limits of De‑escalation

Patients who remain ctDNA‑negative throughout surveillance have very low recurrence risk and excellent long‑term outcomes.
However, these patients represent only those who never convert; individuals who later become ctDNA‑positive are excluded from this favorable group.
Because clinicians cannot predict which ctDNA‑negative patients will remain negative, ctDNA‑guided omission of adjuvant therapy remains unproven.
Ongoing trials are evaluating whether treating only upon molecular recurrence is non‑inferior to immediate adjuvant therapy.

Content is accurate as of the date of release on 16 March 2026.