Colorectal cancer is the second most common cause of cancer-related deaths in the United States. This year, it’s expected that more than 53,000 individuals will die of the disease.
Although screening for the cancer through colonoscopy or sigmoidoscopy is effective in detecting the disease, nearly 40% of eligible adults do not receive a screening test. Blood-based screening tests are being investigated as a potential complementary approach to screening for colorectal cancer that may improve adherence among unscreened individuals.
Results from the large PREEMPT CRC study evaluating the clinical performance of an investigational blood-based colorectal cancer screening test showed the tool accurately detected colorectal cancer risk in adults aged 45 years and older who had an average risk of developing the disease. The research by Shaukat et al will be presented during the 2025 ASCO Gastrointestinal Cancers Symposium (Abstract 18).
Study Methodology
The PREEMPT CRC study is the largest study underway of any blood-based colorectal cancer screening test, enrolling more than 40,000 individuals at 200 sites across the United States. Between May 2020 and April 2022, researchers enrolled participants between the ages of 45 and 85 with an average risk of colorectal cancer. The participants had blood drawn before the bowel preparation for a standard-of-care screening colonoscopy. A total of 27,010 participants had evaluable blood samples and a colonoscopy. Screening colonoscopy and applicable histopathology reports underwent central pathologist review. Blood samples were processed blind to clinical findings.
Primary endpoints included sensitivity for colorectal cancer specificity for advanced colorectal neoplasia (ACN), ACN-negative predictive value (NPV), and ACN-positive predictive value (PPV). A secondary endpoint was sensitivity for advanced precancerous lesions (APL).
The median age of the evaluable participants was 57 years, and 55.8% were women.
Key Results
After performance was weighted to match U.S. Census data for sex and age distributions, sensitivity for colorectal cancer was 81.1% (95% confidence interval [CI] = 71.3%–88.1%), specificity for those without ACN was 90.4% (95% CI = 90.0%–90.7%), NPV for those without ACN was 90.5% (95% CI = 90.5%–90.7%), and PPV for ACN was 15.5% (95% CI = 13.8%–16.2%). Sensitivity for advanced precancerous lesions was 13.7% (95% CI = 12.4%–15.0%).
“PREEMPT CRC is the largest study evaluating a colorectal cancer screening blood-based test to date. The study successfully met all primary endpoints, demonstrating acceptable clinical performance of the investigational blood-based test. The U.S. Census sex-age adjusted clinical performance estimates showed improvement in colorectal cancer and APL sensitivity. This blood-based test may provide a convenient and effective option for colorectal cancer screening in the average-risk U.S. population,” concluded the study authors.
Clinical Significance
“This blood test represents a new tool in our toolbox of colorectal cancer screening options. The study evaluated blood-based screening for colorectal cancer and may provide a convenient and effective option for colorectal cancer screening in the average-risk U.S. population,” said ASCO expert Pamela L. Kunz, MD, Director, Center for Gastrointestinal Cancers at Smilow Cancer Hospital and Yale Cancer Center, in a statement.
Disclosures: For full disclosures of the study authors, visit coi.asco.org.
