Health security

Colon cancer deaths rise among younger adults, and no one knows why

The new study, published Tuesday in the medical journal JAMA, is a followup to one that found that incidence rates of colon and rectal cancers are rising in American adults under 50, the recommended screening age.

According to the previous study, adults born in 1990 could have twice the risk of colon cancer and four times the risk of rectal cancer at the same age had they been born in 1950.

The reason for the rise in both incidence and death rates remains unclear.

"We've known that there's this increasing trend in people under 50 for incidence, but a lot of people were saying, 'Hey, this is good news. This means people are getting more colonoscopies, and cancer's being detected earlier,' " said Rebecca Siegel, an epidemiologist at the American Cancer Society and lead author of the new study..