Colorectal cancer, a common yet preventable disease, has been on the rise, especially among younger adults. However, the introduction of a new blood test for detection brings a beacon of hope.
Colorectal cancer ranks third among the most commonly diagnosed cancers in both men and women in the United States. The numbers are alarming, with the American Cancer Society anticipating 106,590 new cases of colon cancer in 2024 alone. Yet, despite its prevalence, a significant percentage of eligible individuals refrain from undergoing screening tests.
Recent advancements in medical technology offer a potential game-changer: a blood test for early detection of colorectal cancer.
Colorectal cancer, previously the fourth-leading cause of cancer deaths in individuals under 50, has seen a startling surge. It now ranks as the leading cause for men and the second for women. This trend underscores the urgent need for effective and accessible screening options.
Traditional screening tests for colorectal cancer include colonoscopy, stool testing for blood, and stool testing for genetic material. However, these methods often deter individuals due to their invasive nature and the discomfort associated with stool sampling. Consequently, only about 50% to 60% of eligible people undergo these tests.
The advent of the blood test for detecting colorectal cancer marks a promising step forward. Conducted by Guardant Health, a clinical study published in the New England Journal of Medicine revealed the test’s efficacy.
Guardant’s Shield blood test was compared to colonoscopy, currently considered the gold standard for colorectal cancer screening, in a multisite clinical trial involving nearly 8,000 people aged 45 to 84.
The study found that the blood test correctly detected colorectal cancer in 83% of people confirmed to have the disease who were at average risk and not experiencing symptoms. False positives were reported for 10% of the participants, where the test indicated potential colon cancer, but the colonoscopy found nothing.
This blood test, hence, offers an alternative screening method with an accuracy rate similar to stool tests currently used for early cancer detection.
Medical professionals have hailed the introduction of the blood test. Dr. William M. Grady, a gastroenterologist at Fred Hutchinson Cancer Center and the corresponding author of the study, noted that the test results are a significant stride towards developing more convenient tools for detecting colorectal cancer early while it’s still treatable.
CBS News’ chief medical correspondent Dr. Jon LaPook, a gastroenterologist at NYU Langone Health, echoed Dr. Grady’s sentiments. According to Dr. LaPook, the blood test promises to provide an alternative to current screening tests. Its relative ease and the absence of the ‘ick factor’ associated with stool testing could encourage more individuals to opt for screening.
However, Dr. LaPook also pointed out that the blood test detected only 65% of stage 1 colon cancers, which are statistically the most curable. Further research is needed to ascertain its role in colon cancer screening.
Despite the promising results, the blood test is yet to receive approval from the Food and Drug Administration. Most insurers currently do not cover it. However, the test is already available for sale in the U.S. at $895. Guardant Health expects an FDA decision within this year.
As we wait for the decision, it’s crucial to remember that the gold standard for colon cancer screening remains colonoscopy. It can detect colon cancer in its earliest, most treatable stages and can find and remove precancerous polyps before they turn into cancer.
