For women aged 70 and older diagnosed with a common form of breast cancer, identifying the most appropriate level of treatment remains a persistent challenge. Clinicians often lack sufficiently precise tools to tailor care to individual needs, making it difficult to strike the right balance between effective treatment and avoiding unnecessary interventions. This uncertainty is particularly relevant for patients with oestrogen receptor–positive breast cancer who may be considering less aggressive approaches, such as endocrine (hormone-blocking) therapy, instead of surgery and radiation.
A study published in Clinical Cancer Research by investigators at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine suggests that a blood-based test could help guide these complex decisions. The research focused on a carefully selected group of women aged 70 and older who were evaluating endocrine therapy as their primary treatment option while opting to forgo surgery and radiation. The findings point to the potential of a minimally invasive test to support more individualised care strategies in this population.
At the centre of the study is the analysis of circulating tumour DNA (ctDNA), which consists of small fragments of genetic material shed by cancer cells into the bloodstream. By examining blood samples, researchers assessed whether the presence or absence of ctDNA could help identify which patients were less likely to respond to endocrine therapy alone. This approach offers a promising way to monitor tumour behaviour without relying solely on imaging or more invasive procedures.
The results indicated that patients with negative ctDNA tests—either at the start of treatment or shortly after beginning endocrine therapy—were more likely to experience stable disease or tumour shrinkage. For these individuals, avoiding surgery and radiation may not compromise outcomes, sparing them from potential side effects such as scarring, chronic swelling, infection, or nerve damage. Conversely, patients whose ctDNA remained detectable during treatment were more likely to show tumour progression, suggesting that additional interventions, including surgery, might still be necessary.
Importantly, the study did not aim to compare the effectiveness of different treatments. Instead, it sought to identify an early decision-making window that could help clinicians determine which patients are unlikely to benefit from hormone therapy alone. Because ctDNA testing can be performed through simple blood draws, many participants were able to provide samples from home. This reduced the need for frequent hospital visits and enabled broader participation across regional oncology sites, improving accessibility for patients outside major academic centres.
The study also incorporated perspectives from both patients and caregivers, groups whose experiences are often underrepresented in clinical research. More than 80% of patients reported that ctDNA results helped them feel better informed about their treatment decisions, particularly during the initial months of care. Caregivers highlighted the significant demands associated with supporting loved ones through treatment, often requiring them to reprioritise work and personal responsibilities. While the findings are encouraging, researchers emphasise that the study involved fewer than 50 participants and is not yet ready to inform standard clinical practice. Larger studies will be essential to confirm these results and determine how best to integrate this approach into routine care.
More information: Neil Carleton et al, Use of ctDNA in Older Women with ER+ Breast Cancer to Facilitate Surgical De-escalation: A Prospective, Hybrid-Decentralized Trial with Correlative Studies, Clinical Cancer Research. DOI: 10.1158/1078-0432.CCR-25-4079
Journal information: Clinical Cancer Research Provided by University of Pittsburgh
