The circulating tumor DNA (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. For high-risk patients, doctors might consider more aggressive or targeted treatments, often through clinical trials to prevent recurrence. Recent research has been evaluating the utility of ctDNA as a potential prognostic biomarker in patients with metastatic breast cancer.
What is ctDNA?
Circulating tumor DNA is 150–200-base-pair fragments of DNA, which originate from cancer cells and are present in the bloodstream or other body fluids. ctDNA tests can be either tumor-naive or tumor-informed. Tumor informed tests require sequencing the patient’s cancer and then building a custom panel to detect those cancer mutations in blood. Tumor naïve tests do not require genomic sequencing of tumor tissue but rely on a standard mutation and methylation panels that are common to the cancer under study. There are currently no studies directly comparing the two different approaches however the tumor informed test appears to be more sensitive because it is personalized and custom built to provide each individual with a blood test tailored to fit the unique signature of clonal mutations found in that individual’s cancer.
In this recent systematic review and meta-analysis, data from 4,264 patients from 37 studies found that detecting ctDNA in the blood was linked to shorter survival times. This held true regardless of how the ctDNA was detected or how blood samples were collected.
What this means for patients:
- ctDNA in your blood may indicate a more aggressive cancer
- Your doctor might use ctDNA tests to help predict how your disease might progress
- This information could help guide treatment decisions
It is important to remember that ctDNA is just one piece of information used in treatment selection. Your overall health, other test results, and personal preferences all play a role in your care plan. Discuss your individual treatment plan with your oncologist and whether ctDNA testing is appropriate for you.
More Reading
MRD ctDNA Surveillance for Breast Cancer Recurrence
Learn how ctDNA testing can help inform breast cancer management
Join the Conversation on CancerConnect!
Reference:
Dickinson K, Sharma A, Agnihotram RV, et al. Circulating Tumor DNA and Survival in Metastatic Breast Cancer: A Systematic Review and Meta-Analysis. JAMA Netw Open. 2024 Sep 3;7(9):e2431722.
