Guardant Health, a precision oncology company, announced support for an investigator-initiated study led and conducted by The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC – James) to evaluate patient compliance with a blood-based test for colorectal cancer (CRC) screening. 

In this study, The Ohio State University Guardant Shield Colorectal Cancer Screening Project, individuals from minority and underserved populations aged 45 and older who are in need of CRC screening will have the option to receive the Shield blood test, administered by a mobile phlebotomist, as part of their engagement with a community health van. Integrating Shield into mobile health services will allow healthcare providers to bring blood-based screening directly to communities making it accessible for eligible individuals who are not compliant with CRC screening.

Colorectal cancer is the second leading cause of cancer related death in the United States.1 Although CRC screening has been shown to improve survival rates, one in three adults have not completed the recommended CRC screening.2,3 The Appalachian region’s cancer mortality rate is 10% higher than the national average, and the region has higher than average incidence and mortality rates for colorectal cancer specifically.4,5 Over 40% of the Appalachian population is rural, compared with 20% of the national population, and residents are more likely to have lower incomes, lower levels of education, higher poverty and unemployment rates, and poorer health than their non-Appalachian counterparts.6

With a simple blood draw, the Shield test can assist in removing barriers associated with established CRC screening methods because it requires no special preparation, no sedation, no dietary changes, and no extra time away from family or work, and it can be completed as part of any patient office visit.7 Shield test performance was recently clinically validated by the ECLIPSE Study—one of the largest cancer screening studies of its kind—and achieved 83% sensitivity for the detection of CRC. Since the launch of Shield, it has shown approximately 90% adherence demonstrating the value of blood-based screening in a real-world clinical setting.8

“We learned early on in the COVID-19 pandemic that we need to be innovative in how we deliver care to our communities. By deploying a mobile phlebotomist as part of a mobile health clinic, we are further able to understand the potential and ease of a blood test to reach rural and underserved communities,” says AmirAli Talasaz, Guardant Health co-CEO. “The Ohio State University Comprehensive Cancer Center research team has a long legacy of community leadership in Ohio and Appalachia, so we know we are meeting patients where they are, helping to further reduce barriers to access, and improve CRC screening rates to pre-pandemic levels.”

The Ohio State University Guardant Shield Colorectal Cancer Screening Project

This study will enroll individuals aged 45 years and older from minority and underserved populations who are in need of colorectal cancer screening via mobile health clinics. Approximately 300 patients will be enrolled during the study period. Researchers will evaluate attitudes and beliefs about colorectal cancer screening as part of the study, which is funded by Guardant Health, the manufacturer of the Shield test.

The Shield Test

The Shield test detects colorectal cancer signals in the bloodstream from DNA that is shed by tumors, called circulating tumor DNA (ctDNA). Specifically, the test identifies specific characteristics of the DNA that may indicate the presence of cancer.

The clinical performance of the Shield assay was validated using an analyzed set of over ten thousand patient samples in a screening study. The test demonstrated 83% sensitivity in detecting individuals with CRC. Specificity was 90% in both individuals without advanced neoplasia and in those who had a negative colonoscopy result. This test also demonstrated 13% sensitivity in detecting advanced adenomas.


  1. American Society of Clinical Oncology. Colorectal cancer: statistics. website. Updated February 2022. Accessed March 17, 2023.
  2. Joseph DA, King JB, Richards TB, et al. Use of Colorectal Cancer Screening Tests by State. Prev Chronic Dis 2018;15:170535. DOI:
  3. Brenner H, Jansen L, Ulrich A, et al. Survival of patients with symptom- and screening-detected colorectal cancer. Oncotarget. 2016;7(28):44695–44704. doi:10.18632/oncotarget.9412
  4. Association of Community Cancer Centers. Creating a Culture of Health in Appalachia. Accessed online March 17, 2023.
  5. American Cancer Society. Accessed online March 17, 2023.
  6. Appalachian Regional Commission. The Appalachian Region: A Data Overview From The 2016-2020 American Community Survey. Accessed online March 17, 2023.
  7. Rich T, Raymond V, Lang K. Where are we today? Efforts to understand strategies and barriers to physician issuance of a recommendation for colorectal cancer screening: a systematic review. Gastroenterology. 2020;158(6 suppl 1):S-918. doi:10.1016/S0016-5085(20)32981-4.
  8. Shield LDT internal data.