The INVIGOR-11 trial data should be applied carefully. A positive ctDNA result post-surgery indicates when to *initiate* adjuvant immunotherapy. However, if a patient on neoadjuvant therapy becomes ctDNA-negative, this signals treatment efficacy and is a reason to *continue* the planned course, not a justification for stopping it early.

Circulating tumor DNA (ctDNA) is a powerful tool in bladder cancer. A positive result post-surgery is a strong indicator for initiating adjuvant therapy. However, a negative result does not guarantee a cure, as a notable percentage of these patients still relapse, making clinicians cautious about withholding treatment based on a single negative test.

Circulating tumor DNA (ctDNA) identifies post-surgery patients at high risk of relapse. By targeting adjuvant immunotherapy to only this ctDNA-positive group, previously negative clinical trials demonstrate a significant survival benefit. This approach spares low-risk, ctDNA-negative patients from unnecessary treatment and toxicity.

Circulating tumor DNA (ctDNA) is a powerful biomarker for identifying high-risk bladder cancer patients. However, its imperfection presents a new clinical dilemma: with a ~12% relapse rate even in ctDNA-negative patients, clinicians must decide whether to withhold adjuvant therapy and accept that risk, or overtreat the 88% who are likely cured.

Upcoming trials like RETAIN and IMVigor011 are using circulating tumor DNA (ctDNA) to guide complex treatment choices in muscle-invasive bladder cancer. This biomarker-driven approach aims to personalize therapy, potentially enabling bladder preservation for some patients and identifying others who need additional adjuvant treatment.

Contrary to assumption, persistent ctDNA after neoadjuvant therapy does not always mean incurable systemic disease. Surgery alone can clear the ctDNA in roughly half of these patients, suggesting the ctDNA source is often the resectable primary tumor, making cystectomy a potentially curative intervention.

In adjuvant bladder cancer trials, ctDNA status is both prognostic and predictive. Patients with positive ctDNA after surgery are at high risk of relapse but benefit from immune checkpoint inhibitors. Conversely, ctDNA-negative patients have a lower risk and derive no benefit, making ctDNA a critical tool to avoid unnecessary, toxic therapy.

While adjuvant immunotherapy benefits ctDNA-positive patients, it may not be the optimal strategy. Given their near-certainty of relapse (95%), using a single-agent immunotherapy when a more potent combination like EV-Pembro exists for metastatic disease raises the critical question of whether these high-risk patients are being undertreated.

In muscle-invasive bladder cancer, patients whose cell-free DNA remains positive after surgery almost uniformly experience disease relapse. This makes ctDNA a powerful prognostic tool, akin to PSA in prostate cancer, for identifying patients at the highest risk.