Shares of Grail surged 34% Monday after the Food and Drug Administration released documents ahead of an advisory committee meeting Wednesday that will help determine whether the FDA approves the company's multi-cancer blood test.

Galleri looks for chemical tags on DNA that tumors shed into the blood. The test flags a cancer signal and predicts the organ where the cancer is present. Grail has sold it by prescription since 2021, but the FDA has never approved a test that screens for multiple cancers.

In a U.S. study of more than 25,000 adults, Galleri wrongly flagged cancer in 0.15% of healthy people. The test missed most cancers. It caught roughly one-third of those diagnosed within a year, in that study and in a U.K. trial of about 142,000 people. In the U.K. trial, it caught 14% of Stage 1 cancers, the earliest stage. The FDA has asked advisers whether those numbers justify calling Galleri an "early detection" test.