Clinical Trial Evaluates Liquid Biopsy for Early-Stage Breast Cancer Detection

Breast cancer screening relies primarily on mammography, but abnormal findings can lead to additional imaging, biopsy, or repeat imaging after six months, creating anxiety and potentially delaying treatment when cancer is ultimately diagnosed. More than 300,000 women in the U.S. are diagnosed with breast cancer each year, highlighting the need for tools that can provide earlier diagnostic clarity. In response to this need, researchers have launched a clinical trial to evaluate whether a blood test can help detect breast cancer as early as Stage I.

USC Norris Comprehensive Cancer Center (Los Angeles, CA, USA), part of Keck Medicine of USC, has launched a phase 1 clinical trial to evaluate a liquid biopsy for early breast cancer detection. The test is being studied as an adjunct to mammography, not as a replacement for mammograms or breast biopsies. It was developed at the USC Michelson Center Convergent Science Institute in Cancer.

The liquid biopsy is designed to identify rare cancer-associated cells and tumor-associated large extracellular vesicles in blood. These extracellular vesicles are described as small particles released by cancer cells that can enter the bloodstream early in disease onset. Unlike many existing liquid biopsy approaches that focus on small pieces of DNA released by cancer cells, this method also examines cellular and extracellular-vesicle signals that early data suggest may be detectable at the earliest stages of breast cancer.

In the trial, researchers will collect two blood samples one year apart and compare test results with patients’ diagnoses to evaluate accuracy. The study will assess whether the blood test can provide additional information during breast cancer screening and help identify molecular and cellular signs of early-stage disease. Researchers are also evaluating whether the approach could support screening access for women who face barriers to mammography or who have undergone mastectomy.

The liquid biopsy method can identify several common breast cancer-associated rare-cell and extracellular-vesicle signals in the blood. The same technology could potentially be used in the future to screen for other solid tumor, including lung and colon cancer. If the phase 1 trial results are positive, researchers plan a larger phase 2 trial involving a broader patient group.

“Our hope is to determine whether this test can provide more information about breast cancer screening and detection, particularly during the stages of the disease when it may be easier to treat,” said Anastasia Martynova, MD, breast cancer specialist and medical oncologist with USC Norris and principal investigator of the trial. 

“If the test is shown to be effective, it could offer an additional screening option for women who face barriers to mammography, such as those who live in remote areas where access to screening services is limited. It could also have potential applications for women who have undergone a mastectomy, for whom mammograms are no longer an option,” said Amanda M. Woodworth, MD, director of breast health at Keck Medicine and Henry Mayo Newhall Hospital in Santa Clarita, and co-investigator of the trial.

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