From 2010 to 2019, the rate of cancer diagnoses rose from 100 to 103 cases per 100,000 people, according to the study, published in JAMA Network Open. The increases were driven by jumps in certain types of cancer and within specific age, racial, and ethnic groups. Researchers analyzed data for more than 560,000 people under age 50 who were diagnosed with cancer during the 9-year period.
Breast cancer remained the most common type of cancer to affect younger people, while the most striking increase was seen in gastrointestinal cancers. The rate of people with GI cancers rose 15%.
Women were more likely to be diagnosed with cancer, whereas the rate of cancer among men under age 50 declined by 5%. When the researchers analyzed the data based on a person’s race or ethnicity, they found that cancer rates were increasing among people who are Asian, Pacific Islander, Hispanic, American Indian, or Alaska Native. The rate of cancer among Black people declined and was steady among White people.
The only age group that saw cancer rates increase was 30- to 39-year-olds. One of the top concerns for younger people with cancer is that there is a greater risk for the cancer to spread.
The cancer rate has been declining among older people, the researchers noted. One doctor told The Washington Post that it’s urgent that the reasons for the increases among young people be understood.
“If we don’t understand what’s causing this risk and we can’t do something to change it, we’re afraid that as time goes on, it’s going to become a bigger and bigger challenge,” said Paul Oberstein, MD, director of the gastrointestinal medical oncology program at NYU Langone’s Perlmutter Cancer Center, New York. He was not involved in the study.
It’s unclear why cancer rates are rising among young people, but some possible reasons are obesity, alcohol use, smoking, poor sleep, sedentary lifestyle, and things in the environment like pollution and carcinogens, the Post reported.
A version of this article first appeared on WebMD.com.