In the evolving landscape of precision oncology, immunotherapy has become a cornerstone for treating high-risk, early-stage breast cancer. However, clinicians still face a significant hurdle—the treatment’s success in shrinking tumors remains inconsistent, and identifying which patients will benefit most is a persistent challenge.
According to a recent press release, a multi-institutional study led by researchers at the Vanderbilt-Ingram Cancer Center suggests that the answer may lie in a patient’s blood. Published on April 22 in Science Translational Medicine, the research demonstrates that repeated blood sampling—a form of liquid biopsy—can effectively track and predict the immune system’s response to treatment.
A minimally invasive window into the transcriptome
While cell-free DNA (cfDNA) testing is already a staple in many clinical laboratories for cancer monitoring, this study shifts the focus toward the transcriptome. By performing RNA sequencing on 546 peripheral blood samples from 160 patients, the team sought to identify gene transcriptions associated with the activation of antitumor T cells.
The study focused on patients with high-risk, Stage 2 or 3 HER2-negative breast cancers enrolled in the nationwide I-SPY2 clinical trial. Researchers compared those receiving chemotherapy alone against those receiving a combination of chemotherapy and the immunotherapy drug pembrolizumab.
Key findings from the Vanderbilt study
Researchers from Vanderbilt noted the following:
- Predictive power: The liquid biopsy accurately predicted patient response to pembrolizumab by monitoring the clonal expansion of T cells.
- Dynamic monitoring: Unlike a static tissue biopsy, repeated blood draws allow for real-time monitoring of the "evolving" immune response during the course of therapy.
- Accessibility: The researchers noted that this method is a cost-effective and minimally invasive alternative to traditional tissue biopsies.
Implications for clinical pathology and precision medicine
For pathologists and clinical laboratory managers, this research underscores the growing utility of blood-based biomarkers beyond simple mutation detection.
"This tool offers an accessible method for tailoring treatment strategies in breast cancer," the researchers reported, noting that the ability to "tailor treatment regimens" could eventually extend to other solid tumors.
Justin Balko, PhD, PharmD, professor of medicine and pathology at Vanderbilt Health and the paper’s corresponding author, emphasized the collaborative nature of the work. The study relied on samples from the I-SPY2 trial, led by co-author Laura Esserman, MD, MBA, of the University of California, San Francisco. This trial is specifically designed to assess novel treatments based on molecular signatures, highlighting the industry shift toward biomarker-driven care.
The road to clinical validation
While the results are promising, the researchers cautioned that further validation is required before this specific RNA-based liquid biopsy becomes a standard laboratory test.
However, the potential impact is clear. If clinicians can use a simple blood draw to determine if an immunotherapy agent is working in real-time, they can pivot away from ineffective treatments sooner, reducing toxicity for the patient and costs for the healthcare system.
This article was created with the assistance of Generative AI and has undergone editorial review before publishing.
