An American study shows that a blood test can support treatment decisions for a carefully selected group of women aged 70 and over with estrogen receptor-positive breast cancer. These women considered endocrine therapy as primary treatment and avoided surgery and radiation.
The study was conducted by scientists at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine and was recently published in Clinical Cancer Research. “We are learning that not every patient needs the same treatment based on their diagnosis alone. Rather, the treatment should be tailored to the individual,” explains lead author Dr. Priscilla F. McAuliffe, a breast surgeon and oncologist at UPMC Hillman and associate professor of surgery at the University of Pittsburgh School of Medicine.
Researchers analyzed blood samples for circulating tumor DNA (ctDNA) and examined whether its presence or absence could identify patients unlikely to respond to endocrine therapy alone.
A negative ctDNA test indicates a more stable course of the disease
Patients with a negative ctDNA test, either at the start of treatment or after starting endocrine therapy, were more likely to have stable disease or tumor shrinkage. This meant that surgery and radiation – both of which can cause side effects such as scarring, chronic swelling, infection and nerve damage – were unlikely to improve the prognosis of this group of patients.
In contrast, patients whose ctDNA remained positive after endocrine therapy were more likely to have tumor growth during treatment. This suggests that surgery or other treatments may still be necessary to achieve tumor control in this group.
The study did not examine the effectiveness of the treatments. Rather, it focused on identifying an early decision window that can help doctors identify patients who are unlikely to respond to hormone therapy alone.
Because ctDNA can be measured through blood tests, patients were able to participate without frequent hospital visits. Blood samples were often collected from patients’ homes. This reduced travel and allowed researchers to include patients from the entire UPMC Hillman oncology network in the region, not just the main UPMC Hillman center in Shadyside.
“We made every effort to include patients outside of the main academic center, including UPMC Passavant Cranberry, UPMC Jameson and UPMC St. Margaret,” reports study leader Dr. Neil Carleton, postdoctoral researcher at the University of Pittsburgh. “Improving patient-friendly care, including access to clinical trials, is a top priority at UPMC Hillman Cancer Center.”
Better decision support for patients
The study also included feedback from patients and their families – a group that is often not taken into account in clinical studies. Over 80 percent of patients surveyed said the ctDNA test results could help them better inform their treatment decisions, particularly in the first six to 12 months of treatment. Family members reported that supporting loved ones during breast cancer treatment often meant prioritizing caregiving responsibilities over work and other activities.
Based on these results, the researchers suggest that monitoring options from home may be particularly important for family caregivers. For both patients and family caregivers, researchers emphasized the importance of careful patient education and shared decision-making throughout the treatment process.
However, the researchers point out that this was a small study with fewer than 50 patients and the results are therefore not yet transferable to standard practice. Larger studies are needed before this approach can be used routinely.
(lj/BIERMANN)
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