Blood-Based Test Offers Effective Screening Option for Colorectal Cancer

Aasma Shaukat, MD, MPH

Credit: New York University

PREEMPT CRC, the largest prospective study of a blood-based colorectal cancer (CRC) screening test, successfully achieved all primary endpoints for early detection of colorectal cancer, according to late-breaking data presented at Digestive Disease Week (DDW) 2024.¹

The clinical validation cohort showed a clinical performance of the investigational blood-based test for CRC screening, demonstrating nearly 80% sensitivity for CRC and more than 90% specificity for non-advanced colorectal neoplasia (ACN).

“The study suggests that this blood test could offer a convenient and effective screening option for colorectal cancer in the average-risk population, potentially helping to address underutilization of screening methods,” Aasma Shaukat, MD, MPH, the Robert M. and Mary H. Glickman professor of medicine and director of outcomes research in the division of gastroenterology and hepatology at New York University Grossman School of Medicine, said in a statement.²

Screening for colorectal cancer is critical for early detection and widely recommended by medical societies, including the American Cancer Society (ACS).³ However, there is significant under-utilization, with nearly 40% of eligible adults in the United States not up to date with their screening.

The ACS recently lowered the recommended screening age to 45 years old, which expanded the screening-eligible population by 20%.³ Blood-based testing options appear to be preferred among previously unscreened individuals, by nearly 7.5% in some data, suggesting its use among conventional screening methods could improve screening rates.⁴

The PREEMPT CRC study (NCT04369053) explored the clinical performance of a blood-based screening test evaluating molecular signals for CRC among a population considered ‘average-risk.¹

Occurring between May 2020 and April 2022, PREEMPT CRC recruited people aged 45 to 85 considered average risk for CRC, who underwent standard-of-care screening colonoscopy at over 200 sites, primarily in the United States.

Before undergoing bowel preparation for colonoscopy, participants underwent blood collection. All participant colonoscopies and relevant surgical reports underwent central review. Sample processing and colonoscopy review were conducted without the knowledge of the clinical findings.

For the analysis, the co-primary endpoints were sensitivity for CRC, the specificity for the absence of ACN, and the positive predictive value (PPV) for ACN. Acceptance criteria for all primary endpoints were required for a study to be reported as ‘successful.’ Secondary endpoints involved the test's sensitvity for advanced adenomas (AA).

Overall, 48,995 participants were enrolled in PREEMPT CRC—of this population, 32,731 were sequentially enrolled and included in the clinical validation cohort.

Participants had a mean age of 58.1 years and 55.4 of patients were women. Demographics of the clinical validation cohort were 8.2% Asian, 11.9% were Black or African American, and 71.5% were White, while 12.6% of the population were Hispanic or Latino.

Among those in the clinical validation cohort, 27,010 (82.5%) participants had evaluable blood samples and colonoscopy data. Upon analysis, the study met its primary endpoint with a sensitivity for CRC detection of 79.2% (n = 57 of 92; 95% CI, 68.4 - 86.9). Meanwhile, the specificity for non-ACN was 91.5% (n = 22,306 of 24,371; 95% CI, 91.2 - 91.9).

Moreover, the negative predictive value for non-ACN was 90.8% (n = 22,306 of 24,567; 95% CI, 90.7 - 90.9), the PPV for ACN was 15.5% (n = 378 of 2443; 95% CI, 14.2 - 16.8), and the sensitivity for the detection of AA was 12.5% (n = 321 of 2567; 95% CI, 11.3 - 13.8).

“These results underscore the potential of blood-based screening in colorectal cancer screening, providing a noninvasive option that could impact public health,” Shaukat added.

References

1. _{Shaukat A, Meng Z, Sun C, Piscitello A, Xu C, Lee LC, Baldo L, Levin TR. Clinical Evaluation of a Blood-Based Screening Test for the Early Detection of Colorectal Cancer. Lecture presented at Digestive Disease Week 2024, May 18 - 21, 2024.}
2. _{NYU Langone Gastroenterologists Present Clinical Findings & Research at Digestive Disease Week 2024. NYU Langone News. May 20, 2024. Accessed May 21, 2024. https://nyulangone.org/news/nyu-langone-gastroenterologists-present-clinical-findings-research-digestive-disease-week-2024.}
3. _{Montminy EM, Jang A, Conner M, Karlitz JJ. Screening for Colorectal Cancer. Med Clin North Am. 2020;104(6):1023-1036. doi:10.1016/j.mcna.2020.08.004}
4. _{Liang PS, Zaman A, Kaminsky A, et al. Blood Test Increases Colorectal Cancer Screening in Persons Who Declined Colonoscopy and Fecal Immunochemical Test: A Randomized Controlled Trial. Clin Gastroenterol Hepatol. 2023;21(11):2951-2957.e2. doi:10.1016/j.cgh.2023.03.036}