A new blood test may detect the return of breast cancer, a new study has suggested. Researchers at Kumamoto University's Institute of Molecular Embryology and Genetics (IMEG) analyzed tiny, cell-free DNA fragments in the bloodstream, known as cfDNA, and believe these fragments may detect recurrence rather than the conventional method of looking at genetic mutations. Recurrence is when the cancer comes back after treatment, and may develop where it originally started, or spread to nearby lymph nodes or other areas of the body, according to the Cleveland Clinic.
It is generally diagnosed by mammogram, ultrasound, biopsies, scans, or blood tests to detect tumor markers, such as changes in a person's DNA. The new study used samples from 150 breast cancer patients, including 105 from primary breast cancer and 45 from recurrent or metastatic breast cancer, and did not only look at changes in DNA sequence, but what is known as nucleosomes. Nucleosomes are the tiny structures whereby DNA is wrapped around proteins, and the arrangement of these nucleosomes reflects how genes are regulated.
It can be informative about any changes inside cancer cells. CfDNA can be obtained from a blood sample, meaning this new approach has the potential to monitor patients in a less invasive way than current methods, both during and after treatment, and may help detect recurrence earlier. Jeffrey Richard Smith, MD, breast oncologist with Orlando Health Cancer Institute, told Newsweek that early detection is "a priority" when it comes to breast cancer, as once it has spread, "treatment options become more difficult." He said there is a "growing number of technologies that look to detect metastatic disease far earlier," and this study aims to "predict patients that are at risk for developing recurrent or metastatic disease," and identify genetic mutations in the cancer using a blood draw sample.
Dr Donna McNamara, breast medical oncologist at John Theurer Cancer Center, Hackensack University Medical Center, told Newsweek that the study suggests a "minimally invasive liquid biopsy method could significantly impact future breast cancer treatments by enabling earlier and more sensitive detection of recurrence." "Unlike current approaches that rely on imaging or invasive tissue biopsies to find a physical tumor, this technique analyzes cell-free DNA (cfDNA) from a simple blood draw to identify the molecular signature of cancer." Researchers looked at 26 genomic regions known to undergo changes when breast cancer cells become resistant to hormone therapy, and found that recurrent breast cancer was associated with increased numbers of genetic variants, along with shorter cfDNA fragments, according to EurekAlert!. It found that two genomic regions in particular—RERE and SYNPO2—had a nucleosome score that distinguished primary breast cancer from recurrent breast cancer. McNamara described the machine-learning model as the study's "key innovation," as it integrates "multiple cfDNA features," with the ability to "distinguish recurrent from primary cancer with high accuracy." "This allows for the potential detection of relapse before it's visible through conventional methods, enabling doctors to monitor for therapy resistance in real time and make more precise, personalized treatment decisions sooner, all through a potentially more cost-effective test.
The researchers now believe that cfDNA may be key for revealing changes associated with treatment resistance and recurrence of breast cancer, rather than just showing cancer mutations. Smith said that this study and others have shown that "when cfDNA or ctDNA is rising, those patients are at risk for metastatic disease," and that one current problem in medicine is that "we do not know when, or in whom, treatment should be initiated or changed." "What is intriguing about this research is the future possibility of using a simple blood draw to provide accurate surveillance and guide treatment. The hope would be that we could identify a change in the biology of a patient’s cancer and initiate treatment that could be more targeted and personalized." Researchers have said that further research is required, including larger studies on the subject to address the differences in breast cancer subtypes and patient backgrounds.
Sugiko Watanabe, Kan Etoh, Jun Mitsui, Yuta Suzuki, Yutaka Yamamoto, Mitsuyoshi Nakao; Transcriptionally Informed Nucleosome Profiling of Circulating Cell-Free DNA Predicts Breast Cancer Recurrence. Cancer Research Communications 1 June 2026; 6 (6): 1405–1414. https://doi.org/10.1158/2767-9764.CRC-26-0263
Extract — continue reading at the source.
