Guardant Reveal ctDNA Test Shows High Sensitivity in Colorectal Cancer

The Guardant Reveal test, a tissue-free circulating tumor DNA (ctDNA) blood test, demonstrated high sensitivity and specificity in detecting minimal residual disease (MRD) in patients with colorectal cancer (CRC), offering a powerful, noninvasive tool for disease monitoring in this patient population.¹

The test was evaluated in the COSMOS study (UMIN000037765)and delivered a longitudinal sensitivity in stage II or higher colon cancer of 81% (95% CI, 58.1%-94.6%) and 60% (95% CI, 36.1%-80.9%) in rectal cancer. This lower sensitivity in rectal cancer was postulated to be due to a higher number of patients with rectal cancer with metastases to the lungs (55% vs 19%;P =.02) rather than issues with the assay detecting colon vs rectal cancer.

Specificity was calculated from 1461 posttreatment samples and was 98.2% (95% CI, 97.3%-98.9%), with 99.1% (95% CI, 98.2%-99.6%) in samples with at least 16.4 months of follow-up. Further, the negative predictive value was over 91% for recurrence within 1 year of sample collection. The median lead time from ctDNA detection to disease recurrence was 5.3 months (IQR, 3.0-16.4).

“MRD detection through ctDNA analysis is becoming a routine clinical tool that has the potential to revolutionize the management of early-stage CRC for both adjuvant therapy decision-making and recurrence monitoring,” authors wrote in the study published in Clinical Cancer Research. “As a tissue-free assay, this may offer logistical advantages by reducing the burden of tissue handling on healthcare systems as well as improved turnaround time for initial result during the adjuvant decision-making window while maintaining performance comparable to tissue-informed approaches. Tissue-free assays may also be the only option for patients with limited tumor specimens.”

About Guardant Reveal

Guardant Reveal is the first tissue-free MRD detection test in CRC. Using a blood draw, the test is able to quantify tumor fraction and deliver MRD reports in the postsurgery and surveillance settings within 10 days. The test is also available for breast and lung cancers.

In breast cancer, Guardant Reveal demonstrated a 100% specificity rate² and had a median lead time of 7.9 months from detection to disease recurrence. The test was also able to detect ctDNA up to 28.6 months prior to recurrence.³

REFERENCES:
1. Nakamura Y, Tsukada Y, Matsuhashi N, et al. Colorectal cancer recurrence prediction using a tissue-free epigenomic minimal residual disease assay. Clin Cancer Res. Published online August 7, 2024. doi:10.1158/1078-0432.CCR-24-1651

2. Janni W, Huober J, Braun T, et al. Multiomic, plasma-only circulating tumor DNA (ctDNA) assay identifies breast cancer patients with minimal residual disease (MRD) and predicts distant recurrence. Presented at: American Association for Cancer Research Annual Meeting; April 8-13, 2022; Philadelphia, PA. Abstract nr 3403.

3. Guardant Health to present data at San Antonio Breast Cancer Symposium demonstrating utility of liquid biopsy in biomarker identification, therapy selection and residual disease detection. News release. Guardant. November 30, 2023. Accessed August 9, 2024. https://tinyurl.com/3pyz2xt2