Australian scientists have made a groundbreaking discovery in cancer research, revealing that DNA barcoding can be utilized to track cancer cells in both solid and liquid biopsies. This innovative approach has the potential to revolutionize breast cancer diagnosis and treatment, offering a more reliable and comprehensive understanding of the disease. The study, conducted by researchers at the Olivia Newton-John Cancer Research Institute (ONJCRI), WEHI, and Peter MacCallum Cancer Centre, sheds light on the complex nature of tumors and their impact on biopsy results.
Tumors, composed of various cancer cells with differing aggressiveness and treatment sensitivity, have long been a challenge in cancer research. Solid biopsies, taken directly from the tumor, and liquid biopsies, which analyze blood samples, both play crucial roles in understanding tumor diversity. However, the study's findings highlight a critical aspect that has been overlooked until now.
DNA barcoding technology, a sophisticated method, employs lentiviruses to label individual cancer cells with unique DNA tags. These tags serve as distinct identifiers, allowing researchers to track and analyze tumor cells and their corresponding biopsies. The study's key breakthrough was the discovery that different models of tumors exhibit varying amounts of DNA shedding into the bloodstream, even when their cancer cell composition appears similar.
The research team, in a world-first, successfully detected DNA barcodes shed by primary tumors in blood and plasma samples. This finding is significant because it indicates that DNA shedding is not uniform across different models, which could lead to false-negative results in liquid biopsies. Dr. Antonin Serrano, a postdoctoral researcher involved in the study, emphasizes the importance of this discovery.
"DNA barcoding allowed us to investigate entire tumors, solid biopsies, and liquid biopsies. We were able to accurately quantify the level of tumor heterogeneity captured in biopsies. Our findings revealed that DNA shedding in the bloodstream varies widely, influenced by factors such as necrosis and tumor burden, but also differs across preclinical models."
The study also uncovered an intriguing pattern: barcode diversity in the center of primary tumors was significantly higher than in the periphery. This discovery has profound implications for interpreting solid biopsies, as it suggests that the central and peripheral regions of tumors may provide distinct insights. Prof. Delphine Merino, the laboratory head at ONJCRI and a senior author of the study, offers her perspective.
"Our results suggest that both liquid and solid biopsies are generally representative of tumor composition. However, the variability observed between tumors highlights the potential benefits of combining both strategies for a more accurate disease representation."
Prof. Sarah-Jane Dawson, a breast cancer clinician and co-senior author, emphasizes the practical implications of this research. "Liquid biopsies offer a non-invasive method to monitor disease progression. By understanding why some tumors shed more DNA, we can improve the use of liquid biopsies in clinical settings."
The impact of this research extends beyond the laboratory. In 2025, Australia witnessed 20,336 new breast cancer cases, resulting in an estimated 3,353 deaths. The study's findings not only contribute to a deeper understanding of cancer biology but also hold promise for improving diagnostic and treatment strategies, ultimately enhancing patient outcomes.
