Guardant Reveal Blood Test Outperforms Standard Staging in Predicting Colon Cancer Recurrence

Largest published study shows ctDNA testing can better identify high-risk patients to guide personalized treatment and monitoring

Feb. 2, 2026 at 7:39am

Got story updates? Submit your updates here. ›

A new study published in the Journal of Clinical Oncology found that the Guardant Reveal blood test, which detects circulating tumor DNA (ctDNA), was able to identify stage III colon cancer patients at a four-to-six-fold higher risk of disease recurrence or reduced survival compared to standard staging methods. The study, which involved over 2,000 patients, supports the integration of ctDNA testing into routine post-surgery management to better guide adjuvant treatment and surveillance decisions.

Why it matters

Accurately predicting recurrence risk after surgery is critical for colon cancer patients, as it helps clinicians determine the most appropriate course of treatment and monitoring. Standard staging methods based on tumor size and lymph node involvement can miss high-risk patients, leading to under-treatment or unnecessary anxiety. This large study demonstrates that ctDNA testing with Guardant Reveal provides more precise risk assessment to personalize care.

The details

Researchers found that about 20% of patients still had detectable ctDNA in their blood after surgery, indicating the presence of minimal residual disease. These patients had a significantly higher rate of recurrence and worse overall survival compared to those who tested negative for ctDNA. The study also showed that the amount of ctDNA, or tumor fraction, further distinguished those at the highest risk of early recurrence, providing an additional layer of prognostic information.

  • The study results were published in the Journal of Clinical Oncology in February 2026.
  • The study data was previously presented at the 2025 American Society for Clinical Oncology (ASCO) Annual Meeting.

The players

Guardant Health

A leading precision oncology company that developed the Guardant Reveal blood test for detecting circulating tumor DNA (ctDNA).

Mayo Clinic

A nonprofit organization that collaborated with Guardant Health on the study and provided research expertise.

Alliance for Clinical Trials in Oncology

A research organization that also collaborated with Guardant Health on the study.

Frank Sinicrope, MD

Professor of oncology and medicine at Mayo Clinic and the principal investigator for the study.

Craig Eagle, MD

Chief Medical Officer at Guardant Health.

Got photos? Submit your photos here. ›

What they’re saying

“The data suggest that not only the presence of ctDNA, but the amount of ctDNA, as identified by Guardant Reveal may help refine risk beyond standard TNM staging, and could be used to guide adjuvant treatment and surveillance decisions.”

— Frank Sinicrope, MD, Professor of oncology and medicine at Mayo Clinic and principal investigator for the study

“ctDNA testing after surgery improves the accuracy of estimating a patient's risk of cancer recurrence, enabling more tailored recommendations for adjuvant chemotherapy and follow-up monitoring. It also identifies high risk patients who are likely to recur despite standard treatment, and who may benefit from alternative therapeutic approaches.”

— Frank Sinicrope, MD, Professor of oncology and medicine at Mayo Clinic and principal investigator for the study

“This large study adds to growing evidence that ctDNA testing with Guardant Reveal after surgery helps answer the question patients care about most: Am I really cancer-free? Personalizing care after surgery is essential as clinicians and patients decide what comes next. Guardant Reveal fits easily into routine practice and provides timely, actionable insight—helping identify patients at high risk while sparing others unnecessary treatment and anxiety.”

— Craig Eagle, MD, Chief Medical Officer at Guardant Health

What’s next

The judge in the case will decide on Tuesday whether or not to allow Walker Reed Quinn out on bail.

The takeaway

This study highlights the potential for liquid biopsy tests like Guardant Reveal to transform post-surgical care for colon cancer patients by providing a more accurate assessment of recurrence risk. Integrating ctDNA testing into routine practice could help clinicians make more informed, personalized decisions about adjuvant therapy and surveillance, ultimately improving outcomes for high-risk patients.