For women over 70 newly diagnosed with estrogen receptor-positive (ER+) breast cancer, the path to treatment is often complex. Traditional approaches – surgery, radiation, and hormone therapy – can carry significant side effects, particularly for older adults. Now, a study published in Clinical Cancer Research suggests a less invasive approach may be possible for some, guided by a simple blood test that detects circulating tumor DNA, or ctDNA. This emerging field of liquid biopsy offers the potential to “right-size” treatment, avoiding unnecessary interventions for patients who are likely to respond well to hormone therapy alone.
The research, conducted by scientists at UPMC Hillman Cancer Center and the University of Pittsburgh School of Medicine, focused on identifying whether the presence or absence of ctDNA in the bloodstream could predict a patient’s response to endocrine therapy. Endocrine therapy, which blocks the effects of estrogen, is a common first-line treatment for ER+ breast cancer. The goal wasn’t to evaluate the effectiveness of the treatments themselves, but rather to pinpoint an early window for making informed decisions about whether surgery and radiation are truly necessary. “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,” explained Priscilla F. McAuliffe, M.D., Ph.D., a breast surgical oncologist at UPMC Hillman and associate professor of surgery at Pitt’s School of Medicine.
Circulating tumor DNA consists of modest fragments of genetic material shed by cancer cells into the bloodstream. Detecting these fragments can provide a snapshot of the cancer’s activity. In the study, researchers found that patients whose ctDNA tests were negative – either at the start of treatment or after beginning endocrine therapy – were more likely to experience stable disease or even tumor shrinkage. This suggests that for these individuals, the benefits of surgery and radiation – which can include scarring, chronic swelling, infection, and nerve damage – may not outweigh the risks. Conversely, patients whose ctDNA remained positive while on endocrine therapy were more likely to see their tumors grow, indicating that more aggressive treatment options might be needed.
The Promise of Liquid Biopsies in Breast Cancer Care
Liquid biopsies, like the ctDNA test used in this study, are gaining traction in cancer care as a less invasive alternative to traditional tissue biopsies. Instead of surgically removing a sample of tumor tissue, a liquid biopsy analyzes a simple blood draw. This offers several advantages, particularly for older or frail patients. As lead author Neil Carleton, M.D., Ph.D., a post-doctoral fellow at Pitt, noted, the study team intentionally worked to include patients from across the UPMC Hillman network, including sites at UPMC Passavant Cranberry, UPMC Jameson, and UPMC St. Margaret. “Making care more convenient for patients, including access to clinical trials, is a priority at UPMC Hillman Cancer Center.” The ability to collect blood samples at home further reduced the burden on patients, increasing participation and accessibility.
The potential benefits of ctDNA testing extend beyond convenience. It offers a dynamic assessment of the cancer, capturing changes that may not be reflected in a single tissue biopsy. This is particularly important because breast cancers can evolve over time, developing resistance to treatment. Monitoring ctDNA levels can potentially detect these changes early, allowing doctors to adjust treatment plans accordingly. However, it’s crucial to understand that ctDNA testing is not yet a standard practice and is still considered investigational in many settings.
Patient and Caregiver Perspectives
The UPMC Hillman study also uniquely incorporated feedback from both patients and their caregivers, recognizing the crucial role caregivers play in cancer treatment. More than 80% of patients surveyed reported that ctDNA test results would help them feel more informed about their treatment decisions, especially during the initial 6 to 12 months of care. Caregivers, meanwhile, highlighted the significant impact of supporting a loved one through breast cancer, often requiring them to prioritize caregiving responsibilities over work and other commitments. This underscores the importance of convenient monitoring options, like at-home blood collection, and the need for clear communication and shared decision-making between patients, caregivers, and their medical team.
Understanding the Limitations and Future Directions
While the findings are promising, researchers emphasize that this was a relatively small study, involving fewer than 50 patients. Larger, more comprehensive studies are needed to validate these results and determine the optimal way to integrate ctDNA testing into clinical practice. The study did not assess the long-term outcomes of patients who avoided surgery and radiation based on their ctDNA results; it simply identified a potential marker for predicting response to endocrine therapy. Further research will need to address this gap and evaluate whether this approach leads to improved survival rates and quality of life.
The use of ctDNA in breast cancer is part of a broader trend toward personalized medicine, tailoring treatment to the individual characteristics of each patient and their tumor. This approach holds the potential to minimize unnecessary treatments, reduce side effects, and improve outcomes. The National Cancer Institute (NCI) provides extensive information on personalized cancer treatment and ongoing research efforts on their website.
Looking ahead, researchers are exploring the use of ctDNA not only to predict response to endocrine therapy but also to identify other biomarkers that can guide treatment decisions. They are also investigating whether ctDNA can be used to monitor for cancer recurrence after treatment has ended. The field of liquid biopsy is rapidly evolving, and ongoing research promises to unlock even more insights into the complexities of breast cancer and improve the lives of patients.
The next step for this research involves larger clinical trials to confirm these initial findings and establish clear guidelines for implementing ctDNA testing in routine clinical practice. Patients and caregivers interested in learning more about clinical trials at UPMC Hillman Cancer Center can locate information on their website or by contacting their healthcare provider.
This research offers a hopeful glimpse into a future where breast cancer treatment is more precise, less invasive, and tailored to the individual needs of each patient. Share your thoughts and experiences in the comments below.
