In a major leap for cancer diagnostics, new data from the GALAXY study, presented at the 2024 European Society for Medical Oncology (ESMO) Congress, underscores the transformative potential of cell-free DNA (cfDNA) testing in colorectal cancer. Conducted by Natera, Inc., this groundbreaking research highlights how the Signatera test-an advanced tool that detects circulating tumor DNA (ctDNA)-is reshaping the landscape of cancer treatment.
By offering unprecedented insights into disease progression and treatment efficacy, this study promises to enhance survival rates and tailor personalized care for colorectal cancer patients (1^✔ ✔Trusted Source
Improved overall survival with oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial

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What is Cell-Free DNA (cfDNA)?

Cell-free DNA refers to fragments of DNA that circulate in the bloodstream. In cancer patients, a specific type of cfDNA, known as circulating tumor DNA (ctDNA), can be detected. This allows doctors to monitor cancer progression, detect recurrence, and assess how well treatments are working—all without invasive procedures like biopsies.

Cell free DNA for Colorectal Cancer

The study involved 2,240 patients with stage II–IV colorectal cancer. After surgery, patients were monitored using the Signatera test, which analyzes ctDNA levels to detect molecular residual disease (MRD)-small amounts of cancer that may remain after treatment.

Key findings include:

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  Survival Prediction: Patients who tested Signatera-positive (indicating the presence of ctDNA after surgery) had a significantly lower overall survival rate compared to those who were Signatera-negative. The survival rate at 36 months was 71.8% for Signatera-positive patients, compared to 96% for those without detectable ctDNA.
• Chemotherapy Benefits: High-risk patients who tested Signatera-positive and received adjuvant chemotherapy (ACT) had a 50% lower risk of death. This reinforces the ability of Signatera to predict which patients will benefit most from chemotherapy.
• CtDNA Clearance and Survival: Patients who cleared ctDNA and maintained Signatera-negative status had a 100% survival rate at 24 months. Those with only temporary ctDNA clearance had an 82% survival rate, while patients who did not clear ctDNA had just a 61% survival rate.

These results demonstrate that sustained ctDNA clearance through the Signatera test can be a strong predictor of long-term survival for colorectal cancer patients.

Cell free DNA – The Future of Personalized Medicine

Dr. Yoshiaki Nakamura, one of the study’s lead researchers, highlighted how the findings reinforce the role of ctDNA as a powerful tool in predicting post-surgical outcomes. With over 2,200 patients involved, this trial provides critical evidence that Signatera can revolutionize personalized cancer treatment, improving outcomes by helping doctors make informed, data-driven decisions.

The latest findings from the GALAXY study mark a pivotal moment in colorectal cancer treatment, demonstrating that cell-free DNA testing offers a significant advance in predicting patient outcomes and tailoring therapy.

By providing clear evidence of how ctDNA can forecast overall survival and the benefits of chemotherapy, these results promise to enhance personalized treatment strategies and improve patient care. As we move forward, integrating these insights into clinical practice could transform the approach to managing colorectal cancer, offering patients a more targeted and effective path to recovery.

Reference:

1. Improved overall survival with oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment in stage II or III colon cancer in the MOSAIC trial – (https://pubmed.ncbi.nlm.nih.gov/19451431/)

Source-Medindia