Automatically mailing a stool test kit to people's homes might be the best way to boost colon cancer screening among younger adults, a new study says.

More 45- to 49-year-olds went ahead with cancer screening when they received an unsolicited stool test kit in the mail, rather than having to actively opt into screening or choose a test, researchers reported Monday in the Journal of the American Medical Association.

"Removing the need for patients to actively opt into screening can lead to better outcomes, particularly when trying to engage younger, generally healthy adults who may not yet perceive themselves at risk for cancer," senior researcher Dr. Folasade May said in a news release. She's a gastroenterologist and cancer prevention researcher at the UCLA Health Jonsson Comprehensive Cancer Center.

The American Cancer Society lowered its recommended age to begin colon cancer screening from 50 to 45 in 2018, and the U.S. Preventive Services Task Force followed suit in 2021, researchers said in background notes.

This move has increased the detection of early-stage colon cancers among people 45 to 49, according to ACS-led studies also published Aug. 4 in JAMA.