308. Can a Blood Test Detect Breast Cancer Recurrence? Two Patients Share Their Signatera Experience

What if a blood test could detect signs of breast cancer at the molecular level?

Circulating tumor DNA, or ctDNA, is generating growing interest among people diagnosed with breast cancer, particularly those wondering about recurrence, treatment response, and what may be happening in the body before something appears on conventional imaging.

One test you may have heard about is Signatera.

In this episode of Breast Cancer Conversations, Laura Carfang talks with Shannon and Erin, two women with very different breast cancer experiences who both pursued Signatera testing.

Erin was diagnosed with triple-negative breast cancer before her 35th birthday and began exploring Signatera after completing treatment and wondering how she would know if her cancer returned. Shannon was initially diagnosed with DCIS, later developed invasive disease, and is now living with oligometastatic stage IV breast cancer. Her Signatera results became one piece of a much larger diagnostic and monitoring picture.

Together, they share the questions, emotions, uncertainty, and conversations with their healthcare teams that came with pursuing ctDNA testing.

In this episode:

• What circulating tumor DNA (ctDNA) is
• What the Signatera test is designed to detect
• Why some breast cancer patients are asking about ctDNA testing
• Erin's experience asking her oncologist for Signatera testing
• Shannon's experience with changing Signatera results
• What can happen when blood test results and imaging don't seem to tell the same story
• Recurrence anxiety and the desire for more information
• Advocating for yourself while still partnering with your medical team
• What it means to live with oligometastatic breast cancer
• The emotional impact of waiting for test results
• The questions that remain as ctDNA testing continues to evolve

This episode isn't about telling you whether you should—or shouldn't—get Signatera. It's an honest conversation about why patients are interested in this technology, what two women experienced when they pursued it, and why understanding both the possibilities and limitations of emerging testing matters.

Important: The experiences shared in this episode are personal stories and should not be interpreted as medical advice. Talk with your oncology team about whether ctDNA testing is appropriate for your individual diagnosis and treatment plan.