A blood test that accurately detects colon cancer in middle-aged and older people and also rules it out when it is not present can help to increase the rate of screening for the disease in the U.S.
The effectiveness of the new test—reported to be 81 percent accurate in picking up colon cancer in those with the disease, and 90% accurate in ruling it out in healthy people—is reported in the Journal of Clinical Oncology.
Colon cancer is the fourth-leading cause of cancer-related deaths, according to the U.S. Centers for Disease Control and Prevention, with 52,967 people dying from this cancer in 2022 alone—and more men affected than women.
About a third of cases are diagnosed before the cancer has spread outside of the colon or rectum, while 10 percent of cases were only identified after it had spread to lymph nodes, tissues and other organs nearby; in about 20 percent of cases, the disease was diagnosed only after it had spread to distant parts of the body.
The new blood test can help increase the rates of colon cancer screening, the lead researcher on the paper, Dr. Aasma Shaukat, a gastroenterologist at the New York University Grossman School of Medicine, said in a statement.
In some states, as many as 40 percent of people that stand to benefit from colon cancer screening opt not to take it up.
The standard screening test for colon cancer is through colonoscopy, but this can require patients to go through unpleasant bowel preparation and to then be anesthetized during the medical procedure.
"Additional colorectal cancer screening tests that are convenient, safe and easy to complete are needed," Shaukat said. "A blood test has the potential for improving colorectal cancer screening rates."