How MRD Testing Is Reshaping Breast Cancer Risk Assessment

Molecular residual disease, or MRD, testing is emerging as a powerful tool in breast cancer, offering new visibility into what traditional imaging cannot detect.¹ MRD tests, like the Oncodetect® test, work by analyzing circulating tumor DNA, or ctDNA, which allows clinicians to identify trace amounts of cancer DNA that remain after treatment. This approach is helping shift care from reactive to more proactive, risk-informed management.

New findings from the NSABP B-59 substudy, presented at the San Antonio Breast Cancer Society (SABCS)² and the American Association for Cancer Research (AACR)³, underscore the clinical impact. Post-surgical ctDNA positivity was strongly linked to recurrence risk, with ctDNA-positive patients facing a significantly higher likelihood of distant recurrence. In contrast, patients who tested negative showed favorable outcomes, with most remaining recurrence-free at three years.

For oncologists, MRD insights can reshape patient conversations. Rather than relying only on traditional clinical factors, MRD enables more personalized risk assessment. It can help inform decisions on surveillance, additional therapy or de-escalation. As evidence grows, MRD testing is positioned to become a cornerstone of precision oncology in breast cancer care. 

In this sponsored episode of Podnosis, Dr. Priya Rastogi, chief medical officer of the NSABP Foundation, examines how molecular residual disease (MRD) testing is transforming how clinicians assess recurrence risk in triple-negative breast cancer. Drawing on new data from the NSABP B-59 substudy presented at SABCS and AACR, the discussion highlights how circulating tumor DNA (ctDNA) is providing earlier and more precise insight into cancer recurrence through MRD tests, like the Oncodetect® test.

Dr. Rastogi explains how MRD testing can detect residual disease that standard tools may miss, often months or years before clinical recurrence.¹ The conversation explores key findings, including the strong correlation between post-surgical ctDNA positivity and recurrence risk, as well as the prognostic value of ctDNA status earlier in the treatment pathway.^2-3

The episode also looks at how MRD is influencing real-world clinical decisions, from helping to guide patient discussions to informing decisions around treatment escalation or de-escalation. As precision oncology evolves, MRD testing is poised to play a foundational role in improving outcomes and personalizing care. Tune in to hear how these insights are shaping the future of breast cancer management.
 

References:

1. Diergaarde B, Young G, Hall DW, Mazloom A, Costa G, Subramaniam S, Palomares M, Garces J, Baehner FL, Schoen RE; and other members of the Exact Sciences MRD Group. Circulating tumor DNA as a marker of recurrence risk in Stage III colorectal cancer: The α‐CORRECT study. Journal of Surgical Oncology.
2. NSABP Foundation; German Breast Group; Exact Sciences. Circulating tumor DNA–based MRD detection predicts distant recurrence in early triple-negative breast cancer: results from the NSABP B-59/GBG-96-GeparDouze substudy. Presented at: San Antonio Breast Cancer Symposium (SABCS); 2025.  
3. Balic M, et al. ctDNA detection after neoadjuvant therapy predicts pathologic response and recurrence risk in triple-negative breast cancer: NSABP B-59 substudy. Presented at: American Association for Cancer Research Annual Meeting; 2026.