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The U.S. Food and Drug Administration has approved Guardant Health’s Shield blood test for screening for colorectal cancer in adults 45 and older who are at average risk of developing the disease.
CNN
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The U.S. Food and Drug Administration has approved a blood test for use in screening for colorectal cancer in average-risk adults aged 45 and older.
The test’s maker, Palo Alto, Calif.-based biotech company Guardant Health, announced Monday that it is the first blood test to be approved by the FDA as a primary screening option for colorectal cancer, and that it is the first approved colorectal cancer screening blood test that meets Medicare reimbursement requirements. For patients with commercial insurance plans, the cost of the test may vary depending on their individual plan’s coverage. The list price for the test has not yet been announced.
“This is a promising step toward providing more practical tools to detect colorectal cancer at an early stage, when it is more treatable,” said Dr. William M. Grady, a gastroenterologist at Fred Hutchinson Cancer Center, in a statement released Monday by Guardant Health.
In the United States, colorectal cancer is the second leading cause of cancer death. According to the American Cancer Society, more than 53,000 people are expected to die from the disease this year. However, about 70% of colorectal cancer deaths can be prevented through more effective screening.
The test, called Shield, is expected to go on sale next week and will join other types of colon and rectal cancer screening methods, including colonoscopies and home stool tests, as options that health care providers can offer their patients. A simple blood test may be more convenient for some patients, while colonoscopies can feel invasive or home stool tests can be embarrassing.
“The test, which has an accuracy rate for detecting colon cancer similar to stool tests used for early cancer detection, could offer an alternative for patients who might otherwise decline current screening options,” Grady said in the press release.
Current colorectal cancer screening options for people at average risk include a stool-based test done annually or every three years; a traditional colonoscopy every 10 years; a virtual colonoscopy every five years; or a sigmoidoscopy, which uses a tube-like instrument called an endoscope to examine the lower part of the colon, every five years.
According to the National Colorectal Cancer Roundtable, more than one in three adults ages 50 to 75 do not get recommended screenings. The U.S. Preventive Services Task Force recommends that colorectal cancer screening begin at age 45 for people at average risk.
“The persistent gap in colorectal cancer screening rates shows that existing screening options are failing to reach millions of people,” said Dr. Daniel Chung, a gastroenterologist at Massachusetts General Hospital and professor of medicine at Harvard Medical School, in a statement released Monday by Guardant Health.
“The FDA’s approval of the Shield blood test marks a huge leap forward, providing a compelling new solution to fill this gap. This decision will help make screening tests more widely available,” Chung said. “By increasing screening rates and detecting cancer earlier, many more lives can be saved.”
In the United States, approximately 1 in 23 men and 1 in 25 women will be diagnosed with colorectal cancer during their lifetime.
The Shield blood test was already available as a lab-developed test, or LDT, before FDA approval, but the agency’s approval could make the test more widely available and widely covered as another primary screening option. The current out-of-pocket price for the LDT version of the test is $895.
In May, the FDA’s Medical Devices Advisory Committee’s Molecular and Clinical Genetics Panel voted 8-1 that the Shield test is safe to use in people who meet the testing criteria, 6-3 that the test is effective in people who meet the criteria, and 7-2 that the test’s benefits outweigh the risks.
The Shield test works by detecting tumor DNA in blood samples and a The doctor will need to order the test and kit for his patient.
A study of nearly 8,000 people published in March in the New England Journal of Medicine found the test had a sensitivity of 83% and a specificity of 90%. Sensitivity refers to a test’s ability to accurately identify people with a disease and designate them as positive. Specificity refers to its ability to accurately designate people without the disease as negative.
The study found that about 83% of participants diagnosed with colorectal cancer by colonoscopy tested positive for the disease on the Shield test, compared with about 17% who had a false negative.
The test showed a sensitivity of about 88% in detecting stage I, II or III colorectal cancer and a lower sensitivity of about 13% in detecting precancerous lesions.
About 90% of study participants without advanced colorectal cancer or precancerous lesions had a negative blood test result, compared with about 10% who had a false positive result.
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In addition, several research teams and companies are working on developing simple blood tests to detect colon and rectal cancers.
“The argument is that a point-of-care blood test can actually dramatically reduce the incidence rate of very advanced disease and save lives, even if it has less potential to prevent disease,” Robert Smith, senior vice president of early cancer detection science at the American Cancer Society, said in May.
A blood test cannot identify concerning lesions or polyps in the colon or rectum, as a colonoscopy can. Through visual examinations, such as a colonoscopy or sigmoidoscopy, a lesion or polyp that may develop into cancer can be identified and removed, helping to prevent the disease.
“Most people would like to see a blood-based option that would be more accurate in detecting precursor lesions in addition to cancers. But what’s quite remarkable about colorectal cancer screening is that not everyone is willing to do one test or the other,” Smith said. “You have to give people a choice.”