ctDNA in Breast Cancer: Navigating the Gap Between Hype and Clinical Utility

While the oncology community is buzzing with the potential of circulating tumor DNA (ctDNA) to revolutionize breast cancer care, oncology nurses are increasingly on the front lines of a new clinical challenge: the "what now?" of a positive liquid biopsy. For every patient finding peace of mind in a negative blood test, others are grappling with results that lack a clear roadmap for intervention.

Demetria Smith-Graziani, MD, MPH, an assistant professor and medical oncologist at the Winship Cancer Institute of Emory University, highlights that despite the liquid biopsy hype, the field is navigating a complex landscape of professional skepticism, financial risk, and "molecular anxiety." For oncology nurses, understanding the distinction between clinical utility and research-level data is essential for patient education and advocacy.

Metastatic Standard vs Early-Stage Uncertainty

A critical distinction often lost in the excitement over ctDNA is the difference between its use in metastatic disease and its use in early-stage surveillance. According to Smith-Graziani, the medical community views ctDNA through two very different lenses.

In the metastatic (stage 4) setting, ctDNA is increasingly becoming a standard tool. “We isolate the circulating tumor DNA, and we look at those mutations to see if [patients] are candidates for certain targeted therapies,” she explained in a recent interview. This replaces the need for invasive tissue biopsies to identify mutations, such as ESR1, that guide treatment changes.

However, for patients with early-stage disease (stages 1-3), the utility of ctDNA remains in the research phase. Although the technology can detect microscopic fragments of cancer DNA, the clinical consensus on actionable steps is far from settled. Alexis Ann LeVee, MD, a breast medical oncologist with UCLA, echoes this caution: “Right now, we don’t quite know how to act on these positive ctDNA test results.”

The "Lead Time" Dilemma: Detection Without Prevention?

One of the most significant sources of skepticism revolves around "lead time." Updated results from the CHIRP study presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting showed a median lead time of 1.4 months. To a patient, this feels like a head start; to a clinician, it represents a period of profound uncertainty.

“What we don’t yet know is how can we then prevent that recurrence from happening?” asked Smith-Graziani. The fundamental question is whether starting treatment earlier based on a blood test improves long-term survival. LeVee notes that, traditionally, studies have not shown that earlier detection of metastatic disease in asymptomatic patients improves long-term overall survival (OS).

The Accuracy Gap: False Positives and Negatives

The scientific community also maintains skepticism regarding the negative predictive value of current assays. Smith-Graziani pointed to recent data regarding response to neoadjuvant therapy among patients with triple-negative and HER2-positive breast cancer. Researchers hoped that clearing ctDNA from the blood would be a 90% accurate predictor of a pathologic complete response (pCR).

“It was more like 50% to 60%,” Smith-Graziani noted. “It wasn’t really as predictive as they thought.”

This gap in sensitivity means a negative test could provide false reassurance, while a positive result may trigger significant distress without a corresponding standard-of-care intervention.

Direct-to-Consumer Risks and Financial Toxicity

Perhaps the most pressing concern for oncology nurses is the rise of direct-to-consumer testing. Patients are increasingly ordering these tests independently, often receiving results without a clear clinical plan. Smith-Graziani warned this can lead to "molecular anxiety," a state where a patient knows they are at high risk for recurrence but has no standard options to mitigate that risk.

Beyond the psychological burden lies "financial toxicity." Because ctDNA testing for early-stage surveillance is not yet included in the National Comprehensive Cancer Network (NCCN) guidelines, insurance coverage is inconsistent. Patients may face steep out-of-pocket costs for tests administered as frequently as every 3 months.

The Path Forward

Dr. Sucharu Prakash, Medical Director of Quality Services for Texas Oncology, admits that while doctors can be slow to adopt new technology, the data must "mature" before widespread adoption is responsible.

For Smith-Graziani, the conclusion for those in the clinic is clear: For patients with early-stage breast cancer, ctDNA is currently a tool for the laboratory. She recommends that patients pursue these tests within the context of a clinical trial to ensure they are contributing to the research that will eventually turn these unanswered questions into lifesaving protocols.