A new report indicates that young white people are increasingly at risk of dying of colorectal cancer, a disease that usually affects older pepole. The study, which was published in the Journal of the American Medical Association, found that death rates for colorectcal cancer for adults under 55 have jumped in the past decade, rising from 3.6 deaths per 100,,000 people per year to 4.1 between 2004 and 2014.

The same was not true for black people, who actually saw mortality from colorectal cancer decline over that same period. Scientists think it’s possible widespread colonoscopy testing are simply doing a better job of catching it, but this new report says that might not be why.

It’s actually a change in a trend, as rates had been declining by about 2 percent per year, so this appears to represent a true increase in colorectal cancer incidence. Also, the largest increases in diagnoses was for metastatic cancer, not for the localized stage as would be the case if increased detection were the cause.

“A new report finds that colorectal cancer mortality rates have increased in adults under 55 since the mid-2000s after falling for decades, strengthening evidence that previously reported increases in incidence in this age group are not solely the result of more screening. The rise was confined to white individuals according to the report, which appears in the Journal of the American Medical Association,” reads a statement from the American Cancer Society. “As reported previously by American Cancer Society investigators, colorectal cancer (CRC) incidence has been increasing in the United States among adults younger than 55 years since at least the mid-1990s. The increase thus far is confined to white men and women and is most rapid for metastatic disease. CRC mortality overall is declining rapidly, masking trends in young adults, which have not been comprehensively examined.”