Blood Test May Help Tailor Breast Cancer Treatment for Older Women

A simple blood test may one day help doctors determine the best treatment approach for women age 70 and older with a common form of estrogen receptor-positive breast cancer. In a study published in Clinical Cancer Research, researchers at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine found that testing for circulating tumor DNA (ctDNA)—tiny fragments of genetic material shed by cancer cells—may help identify which patients are likely to respond to hormone-blocking (endocrine) therapy alone, allowing some women to avoid surgery and radiation.

Patients whose ctDNA test was negative before or shortly after starting hormone therapy were more likely to have stable disease or shrinking tumors, suggesting additional treatments might not improve outcomes. However, patients whose ctDNA remained positive were more likely to experience tumor growth, indicating surgery or other treatments could still be needed.

"We are learning that not every patient needs the same treatment based simply on their diagnosis," said senior author Priscilla F. McAuliffe, M.D., Ph.D., a breast surgical oncologist at UPMC Hillman Cancer Center. "Care should be right-sized for each individual." Researchers note that the study included fewer than 50 patients, so larger studies are needed before the test becomes part of routine care. An added benefit of the study was that many blood samples were collected in patients' homes, reducing travel and making participation easier for older adults.