United States: The FDA has recently approved Guardant Health’s blood test, Shield, for the colon cancer screening. However, this won’t replace colonoscopies, doctors are hopeful it will improve screening rates for this major cancer.
Earlier costing USD 895 out-of-pocket, Shield is now expected to be covered by Medicare and private insurance, increasing its accessibility for patients of some sections.
Expert Reactions and Considerations
As reported by NBC news, Dr, Arvind Dasari who is an associate professor in the department of the gastrointestinal and the medical oncology at the University of the Texas MD Anderson Cancer Center called the approval a “Welcome development.”
But, he cautioned, “we’ll have to wait and see what the impact will be in the terms of improving screening and also reducing the incidence of mortality”.
The American Cancer Society almost estimated that more than 53,000 people will die of colorectal cancer this year.
Effectiveness and Limitations
Research published in the March showed Shield was 83 % effective in finding the colorectal cancers and it basically works by detecting the DNA and that cancerous Tumours release into the bloodstream.
It’s most effective in in finding later stage cancers when the tumours release more of that DNA the study found that Shield only detected 13 % of the earlier-stage polyps.
This particular test would need to be given at least every three years, starting at the age 45- the same age it’s recommended to being colorectal screening.
Important Follow-Up Required
A positive test isn’t mandatory a diagnosis and if the results shows that the cancer is present the patient would still need a colonoscopy so the doctors can see where tumours are and how far they’ve progressed.
“People have to understand that a positive Shield test requires a colonoscopy to confirm that you have an advanced lesion or colorectal cancer, or that the results were false,” said Robert Smith, very senior vice president of Early Cancer Detection Science at the American Cancer Society. “A test like this is not complete if it’s positive and you have not had a colonoscopy.”
