Blood tests are emerging as an innovative tool for colorectal cancer detection because they have the potential to save lives compared to no screening at all. For now, however, patients should stick with more proven techniques, the researchers said.

“The development of blood tests for cancer detection is a true scientific breakthrough that could completely change the world of cancer detection,” lead study author Dr. Uri Ladabaum, director of the Gastrointestinal Cancer Prevention Program at Stanford Medicine, in Palo AltoCalifornia, UPI said.

“But the first-generation blood tests for colorectal cancer are not as good as our current alternatives,” Ladabaum said.

The researchers also determined that colonoscopies — and stool screening — were more cost-effective than blood tests.

But the blood tests will help reduce colorectal cancer deaths only if patients get them every three years and go on to colonoscopy after a positive result, Ladabaum noted.

“People should think carefully about the relative expected benefits of different screening options and how they value that against convenience,” he said.

With current screening and prevention efforts, approximately 4% of American adults will be diagnosed with colorectal cancer. Regular screening can help detect cancer as well as precancerous polyps early, reducing the risk of developing the disease and dying.

The US Preventive Services Task Force recommends that all adults between the ages of 45 and 75 be screened for colorectal cancer.

For a long time, screening consisted of either a colonoscopy once every decade or a stool test every one to three years. While the exam can detect colorectal cancer, it can also prevent it if your doctor removes precancerous polyps.

Still, about 1 in 3 American adults in the recommended age range haven’t had any colorectal cancer screenings, so experts hope new options could convince them to get tested.

To compare the effectiveness of different screening methods, researchers pooled previously published data on six commercially available or developing stool and blood tests, as well as colonoscopy.

They found that of 100,000 average-risk people who undergo colonoscopy every 10 years, 1,543 would develop colorectal cancer and 672 would die.

“This population-wide use of colonoscopy is unrealistic,” Ladabaum said. “That’s why there’s such intense interest in new, non-invasive alternatives.”

The number of people who develop cancer after screening with the new blood tests is much higher — between 4,310 and 4,365, he said. These tests are recommended every three years.

Meanwhile, about 2 1/2 times as many people — 1,604 to 1,679 — died of colorectal cancer in the blood test group than in the colonoscopy group.

Projections for blood tests are still considerably lower, however, than rates among people who skip all tests. In this scenario without testing, 7,470 would develop colorectal cancer and 3,624 would die.

“Screening with first-generation blood tests is substantially better than no screening at all,” Ladabaum said. “But for now, established stool tests and screening colonoscopy remain the most effective and cost-effective options.”

Other gastrointestinal specialists emphasized the value of the study in comparing different screening modalities for colorectal cancer.

Dr. Jatin Roper, a spokesman for the American Gastroenterological Association, told UPI that most people 45 and older are eligible for colorectal cancer screening. He was not involved in conducting the research.

“This study will help them and their doctors decide which test to do,” said Roper, who is also a gastroenterologist and gastrointestinal cancer geneticist at Duke University Durham School of Medicine, NC

“Most importantly, this study will help health care administrators decide on the coverage of new colorectal cancer screening tests,” he said.

Dr. Lilian Chen, chief of colon and rectal surgery at Tufts Medical Center in Boston, said some patients are at higher risk of complications from colonoscopy.

“I think if the patient, for whatever reason, is not willing to have a stool test or a colonoscopy, this blood test can be a reasonable alternative” to start screening and then follow up with a colonoscopy if the result is abnormal .

“Colonoscopy is still the gold standard for colorectal cancer screening,” said Dr. Jacquelyn Turner, chief of colon and rectal surgery at Tulane School of Medicine in New Orleans, noting that it is better at detecting cancer in stage 1, as well as polyps. .

“The other screening tests are positive once a mass is large enough to bleed or shed DNA cells,” Turner said.

“In other words, the next-generation tests are good at detecting cancer after it has already developed,” she said. Again, the difference between cancer prevention and cancer detection should be highlighted and explicitly explained to patients.