A coverage decision by the biggest name in US health insurance has given a lift to Guardant Health and to the idea that a blood test could become a routine way to screen for colorectal cancer. This is a report on a market move and the news behind it, not investment advice.
The move
Guardant Health's shares jumped nearly 20% in the week after the news and now trade close to a 52-week high, Yahoo Finance reported. The catalyst was a decision by UnitedHealth Group to cover Guardant's Shield test as a first-line screening option for members aged 45 to 75, matching the terms of Medicare's existing coverage, according to Yahoo Finance.
Wall Street took the decision as a meaningful expansion of Shield's potential market. The Bernstein analyst Eve Burstein raised her price target on the stock to $200 from $175 on July 2 while keeping an "outperform" rating, and estimated the UnitedHealth move gives Guardant access to around 10 million newly reimbursed customers, Yahoo Finance reported. A price target is an analyst's view of where a stock might trade, not a fact about where it will.
What Shield is
Shield is a blood test for colorectal cancer. It won approval from the US Food and Drug Administration in July 2024 as the first blood-based test cleared as a primary screening option for the disease, in average-risk adults aged 45 and older, the ASCO Post reported. Its appeal is simplicity: a blood draw at a routine appointment, rather than the preparation and procedure of a colonoscopy or the collection involved in a stool-based test. That convenience matters because a large share of eligible adults skip screening altogether.
The catch
The trade-off is what the test can and cannot see. In the trial data behind its approval, Shield detected about 83% of colorectal cancers, but was far less sensitive to advanced precancerous growths, catching only around 13% of them, the ASCO Post reported. That is the crux of the debate around blood-based screening: a colonoscopy can find and remove precancerous polyps before they ever turn into cancer, while a blood test is better at flagging cancer that is already present. As Yahoo Finance noted, blood-based tests catch early-stage cancers less reliably than stool-based ones.
Why the coverage matters
For a diagnostics company, a test is only as valuable as its reimbursement, because without insurance coverage few patients will pay out of pocket and few doctors will order it. That is why an insurer's decision can move the stock as much as a clinical result. UnitedHealth's backing, the largest commercial endorsement Shield has secured, lowers the cost barrier for a big pool of patients and signals confidence in the test's role. Whether blood-based screening ultimately complements the colonoscopy or competes with it will depend on how doctors weigh its convenience against its blind spot for precancer, and on how many more insurers follow UnitedHealth's lead.
