In 2023, the Centers for Medicare & Medicaid Services determined that Signatera’s molecular residual disease (MRD) test designed to detect circulating tumor DNA, or ctDNA, met coverage requirements for adjuvant and recurrence monitoring in patients with stage IIb or higher breast cancer. Medicare’s coverage applies across all breast cancer subtypes including HR-positive, HER2-positive, and triple-negative breast (TNBC) cancers.
In a recent study presented at the San Antonio Breast Cancer Symposium, researchers evaluated over 1,600 patients with early-stage breast cancer using a personalized blood test called Signatera’s ctDNA test. Data was analyzed from patients with stage I-III HR+/HER2- breast cancer to determine actionable genetic mutations and evaluate genetic mutation impact on disease recurrence and survival.
Key Findings
- Detecting Remaining Cancer
- About 17.5% of patients had cancer DNA in their blood after surgery.
- This suggests some cancer cells remained in the body after surgery. This is referred to as minimal residual disease and cannot be detected using PET/CT scans.
- Actionable Genomic Changes
- 44% of patients with detectable cancer DNA had mutations, that could be targeted with specific treatments; these included PIK3CA, AKT or ESR1
- Higher Risk Group Identified
- Patients with both ctDNA in their blood and a specific mutation had a higher risk of cancer returning.
What Does This Means for Patients?
The ctDNA blood test is already being used in appropriate patients with stage IIb or higher breast cancer to help identify which patients with early-stage breast cancer are at higher risk of their cancer coming back. Results from this study demonstrate the utility of MRD monitoring in earlier stages of breast cancer. Early detection of patients at high-risk of recurrence or those with targetable mutations gives patients more time for treatment planning and to consider targeted treatments to prevent recurrence as well as participation in clinical trials. Studies evaluating escalation of treatment with more aggressive therapies are ongoing to determine whether this approach can improve the outcomes for high-risk patients. Patients should discuss how ctDNA may be used to manage their cancer prior to ordering the test to ensure they understand how or if the test results will impact their individual treatment.
More Reading
- Join the Conversation on CancerConnect! Breast Cancer- Positive ctDNA Signetera blood test-what next?
Reference:
Presenting Author Lipsyc-Shart M, et al. PS9-01 – Abstract SESS-1614: Actionable Genomic Alterations in Localized Hormone Receptor Positive (HR+) Breast Cancer and Impact on Clinical Outcomes: Results from Comprehensive Whole Exome Sequencing (WES) and Tumor-Informed circulating tumor DNA (ctDNA) analysis. Presented at the 2024 San Antonio Breast Cancer Symposium, December 10-13, 2024. San Antonio, TX.
