Revolutionary Blood Test Shows Promise in Early Detection of Colon Cancer

A groundbreaking blood test has demonstrated an impressive ability to detect colon cancer with over 80% accuracy while successfully ruling out the disease in 90% of healthy individuals. Researchers presented these findings at the 2025 American Society of Clinical Oncology Gastrointestinal Cancers Symposium in San Francisco.

The results, which garnered significant attention, were also published in the Journal of Clinical Oncology. This innovative approach could significantly enhance early detection and screening for colorectal cancer.

Study Overview and Methodology

In this extensive study, researchers analyzed blood samples from more than 27,000 adults aged 45 to 85 prior to their colonoscopy screenings. Participants were enrolled between May 2020 and April 2022, providing a robust dataset for evaluation.

The researchers sought “molecular signals of advanced colorectal cellular changes” in these blood samples, comparing the results to the outcomes of the colonoscopy. The test’s sensitivity—its ability to correctly identify existing colon cancer—was found to be 81.1%. Moreover, the specificity—identifying those without the disease—reached 90.4%, indicating a strong predictive value.

Need for Enhanced Screening Options

Lead study author Aasma Shaukat, MD, from NYU Grossman School of Medicine, emphasized the need for additional colorectal cancer screening methods that are not only convenient but also safe. In a press release from the American Society of Clinical Oncology (ASCO), she highlighted, “Until now, we have only had stool-based tests and colonoscopy or sigmoidoscopy. A blood test has the potential for improving colorectal cancer screening rates.”

Another expert, Pamela Kunz, MD, from Yale School of Medicine, pointed out that this experimental blood test offers a promising addition to colorectal cancer screening methods available today. “The study evaluated blood-based screening for colorectal cancer and may provide a convenient and effective option for average-risk individuals in the U.S.,” she said.

Liquid Biopsies: Changing the Cancer Screening Landscape

Pashtoon Kasi, MD, a medical director at City of Hope Orange County in California, refers to these blood tests as “liquid biopsies,” defining them as a transformative advancement in cancer care. He explained, “It is a simple blood test looking at different components of cancers or tumors that are being shed in the bloodstream.”

Kasi noted that several types of liquid biopsies are progressively integrating into clinical practice. Certain tests focus specifically on early detection of colon and rectal cancer, while others are designed for what are known as multi-cancer early detection tests, which can identify multiple cancer types from a single blood draw.

Limitations and Future Considerations

Despite the promising results of this blood test, Kasi cautions against using these tests as substitutes for colonoscopies, which remain the gold standard in colon cancer screening. Colonoscopies provide the added benefit of preventing colon cancer through the detection and possible removal of polyps—non-cancerous growths that may become malignant.

“Blood tests are designed to detect cancer, not prevent it,” Kasi explained. Should a blood test indicate the presence of cancer, further testing such as a colonoscopy will be essential.

The Urgency of Expanded Screening Initiatives

Early detection of colon cancer generally leads to better treatment outcomes. Research indicates that colon cancer progresses slowly and may not present symptoms in its early stages. Alarmingly, studies reveal that 33% to 50% of individuals forgo necessary colon cancer screenings. The development of a blood test could address this gap.

Kasi highlighted the public’s hesitation regarding traditional screening methods, often due to the taxing preparation involved with colonoscopy. The blood test may represent a vital opportunity to enhance screening rates among individuals who would typically avoid traditional methods.

A Growing Concern: Rising Colon Cancer Rates in Younger Adults

The rising incidence of colorectal cancer, particularly among those under 50, underscores the urgency of developing and implementing expanded screening options. “Colorectal cancer is on a particularly steep incline so steep that by 2030, it will be the leading cause of cancer death for young adults in the United States,” Kasi warned, emphasizing the need for continuous research and discussion surrounding these topics.

Colorectal cancer is currently the fourth most common cancer in the U.S. and the second deadliest, according to the Colorectal Cancer Alliance. Ongoing research will assess the long-term efficacy of the new blood test.

Path Forward for Cancer Screening

As regulatory bodies evaluate blood-based tests, their clinical availability is anticipated in the near future. Lead study author Shaukat pointed out that the new tests are specifically aimed at men and women aged 45 to 85 who are at average risk for colon cancer and due for screening.

It is important for individuals with a family history of colon cancer or other risk factors to consult their healthcare providers regarding appropriate screening options.

Ultimately, the introduction of this blood test not only represents a significant step forward in colorectal cancer screening but also a beacon of hope for improving early detection rates and patient outcomes in the future.