The second-leading cause of cancer deaths in the U.S. is actually highly treatable — when caught early.
Of the 52,967 people who died from colon cancer in the U.S. in 2022, as many as 20% were not up-to-date with their screening.
The gold standard of screening is a colonoscopy, which the American Cancer Society recommends people begin at age 45. However, the required prep (which involves a laxative to empty your bowels) intimidates many.
Stool-based testing is gaining popularity as a less-invasive, at-home option. And a new blood test called Shield may be available soon to screen for colon cancer-related DNA markers. Guardant Health, the company that makes Shield, says the Food and Drug Administration will likely decide on Shield’s approval in the second half of 2024.
“Gastroenterologists are excited about the Shield blood test because it has promise to help more patients get screened,” says Benjamin Levy, MD, a gastroenterologist at UChicago Medicine. “Many of our patients would prefer a blood-based screening test compared to a colonoscopy or stool sample.”
However, the test is not as precise as a colonoscopy. It currently has an 83.1% sensitivity rate for colorectal cancer; however, Levy says, “I hope this technology continues to improve. Ideally, it would have over a 90% sensitivity so that it can help patients and gastroenterologists screen with better certainty.”
A concerning blood test result would still require a follow-up colonoscopy, but the new tests may allow some to postpone the procedure.
Originally published in the Fall 2024/Winter 2025 print issue.
Rebecca is an experienced registered dietitian, freelance writer, and yoga teacher who loves to read, hike, and tend her garden.
