Guardant Reveal Test Is Effective in Predicting Recurrence in Stage II and Higher CRC

Craig Eagle, MD

The Guardant Reveal liquid biopsy test demonstrated utility in predicting disease recurrence in patients with stage II and higher colorectal cancer (CRC), according to findings from the prospective COSMOS study (UMIN000037765) published in Clinical Cancer Research.¹

The tissue-free epigenomic test, which utilizes minimal residual disease (MRD) detection, displayed a specificity of 98.2% (95% CI, 97.3%-98.9%) in 1461 post-treatment samples from 290 patients without recurrence, at a median lead time of 5.3 months (IQR, 3.0-16.4) and a maximum lead time of 28.7 months. Additionally, the test sensitivity was 99.1% (95% CI, 98.2%-99.6%) in the subset of samples with a minimum of 16.4 months of follow-up (n = 863). All patients (n = 342) were able to undergo evaluation without necessary tissue testing.

“In the COSMOS study, we observed sensitive and specific detection of minimal residual disease in resected colorectal cancer using the Guardant Reveal tissue-agnostic epigenomic-based ctDNA assay,” Yoshiaki Nakamura, MD, PhD, chief, International Research Promotion Office, Department of Gastroenterology and Gastrointestinal Oncology, National Cancer Hospital East, in Chiba, Japan, and a co-lead author of the study, stated in a news release.² “The use of a tissue-free assay offers health care systems significant logistical advantages by reducing the burden of tissue handling, as well as a shorter initial turnaround time for the result during the adjuvant decision-making window, while maintaining overall longitudinal performance comparable to previously reported tissue-informed approaches.”

Guardant Reveal is the first tissue-free test for MRD detection in CRC; the test is also available for breast and lung cancer. The test uses a simple blood draw to evaluate over 20,000 epigenomic regions to accurately quantify tumor fraction. Guardant Reveal can produce results in less than 10 days to provide clinicians with information to aid clinical decision-making in the post-surgery and surveillance settings in early-stage settings.^1,2

COSMOS is an ongoing, multicenter, nonrandomized observational study that enrolled patients with clinical stage 0 to III CRC in Japan. To be eligible for the study, patients needed to be at least 20 years of age and have a planned surgical resection. Patients with stage I and higher disease were eligible for the MRD study.¹

MRD study-eligible patients had blood samples collected at day 28 and every 3 to 6 months after surgery for up to 5 years or until recurrence; samples were also collected at the time of recurrence, when possible. CT was performed every 6 months post-resection and happened concurrently with samples collected at 6-, 12-, 18-, 24-, 30-, 36-, 42-, 48-, 54-, and 60-months after surgery.

The median age of patients with stage I to III disease included in the interim analysis was 70 years and 44% were female. The study cohort included patients with CRC (65%) and rectal cancer (35%); most patients had pathologic stage II or III disease (62%). Two patients who underwent R2 resection were excluded, as were 2 others with no post-operative timepoints.

Additional findings from COSMOS showed that Guardant Reveal had a longitudinal sensitivity for recurrence detection of 81% (95% CI, 58.1%-94.6%) in patients with stage II or higher colon cancer (n = 21) and 60% (95% CI, 36.1%-80.9%) in those with stage II or higher rectal cancer (n = 20). The test sensitivity was 100% in patients with liver metastases; the test had a sensitivity of 53% and 40% in patients with lung or peritoneum metastases, respectively.

“Studies have established an association between the presence of residual disease after surgery and a higher probability of recurrence in early-stage colon cancer,” Craig Eagle, MD, chief medical officer, Guardant Health, added in the news release.² “The COSMOS study provides strong support for the use of the Guardant Reveal test to help inform adjuvant therapy decisions for patients with stage II or III colon cancer and, in post-treatment surveillance, to detect recurrence earlier than standard of care.”

References

1. Nakamura Y, Tsukada Y, Matsuhasi 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. Guardant Health COSMOS study published in Clinical Cancer Research validates utility of guardant Reveal liquid biopsy test for predicting recurrence in colorectal cancer. News release. Guardant Health, Inc.August 7, 2024. Accessed August 7, 2024. https://www.businesswire.com/news/home/20240807656024/en