A study published on Mar. 19 in Clinical Cancer Research reports that a blood-based test could help personalize treatment decisions for women age 70 and over with estrogen receptor–positive breast cancer who are considering hormone-blocking therapy instead of surgery or radiation.
This research is important because clinicians have limited tools to tailor treatments for older patients, and finding less invasive options can improve quality of life. The study was conducted by scientists at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine.
Researchers analyzed blood samples from patients to detect circulating tumor DNA (ctDNA), which are small fragments of genetic material shed by cancer cells. They found that patients whose ctDNA tests were negative, either before or after starting endocrine therapy, were more likely to have stable disease or tumor shrinkage. This suggests that surgery and radiation might not provide additional benefit for these patients, as both procedures can cause side effects such as scarring, swelling, infection, and nerve damage.
Conversely, those whose ctDNA remained positive after receiving endocrine therapy were more likely to experience tumor growth while on medication. For this group, surgery or other treatments may still be necessary to control the tumor. "We are learning that not every patient needs the same treatment based simply on their diagnosis, and instead, care should be right-sized for each individual," said Priscilla F. McAuliffe, M.D., Ph.D., senior author of the study.
The study also made participation easier by allowing many blood samples to be collected from patients' homes rather than requiring frequent hospital visits. "We worked really hard to include patients outside the main academic center... Making care more convenient for patients, including access to clinical trials, is a priority at UPMC Hillman Cancer Center," said Neil Carleton, M.D., Ph.D., lead author.
Feedback from both patients and caregivers indicated that over 80% felt ctDNA results helped them feel better informed about their treatment choices during the first six to twelve months of care. Researchers noted that home monitoring options could ease burdens on caregivers as well.
The authors caution that this was a small study involving fewer than 50 participants and larger studies will be needed before these findings can influence standard practice.
