A blood test for circulating tumor DNA (ctDNA) could help women aged 70 and over with estrogen receptor-positive breast cancer to personalize treatment. Scientists from the University of Pittsburgh and UPMC Hillman Cancer Center have shown in a study that the test can indicate whether hormone-blocking therapy alone is sufficient or if surgery and radiation therapy are necessary.
Patients with a negative ctDNA finding – either before or during hormone therapy – more often showed stable tumors or even shrinkage. For them, invasive measures such as surgery or radiation, with their typical side effects, might be avoidable. In contrast, tumors continued to grow in patients with persistently positive ctDNA findings despite hormone therapy, meaning additional interventions might be necessary.
The study was conducted decentrally: blood samples were often taken at home to reduce the burden on older patients. More than 80 percent of participants reported that the test informed them better about the therapy decision. Caregiving relatives were also involved.
The authors emphasize that this is a small study with fewer than 50 patients. The results are not yet ready for routine use. Larger follow-up studies are needed.
The study was published today in the journal Clinical Cancer Research (DOI: 10.1158/1078-0432.CCR-25-4079).
The information comes from a press release from the University of Pittsburgh dated March 19, 2026.
