Health

Time - In 2019, about 103 cancers were diagnosed among every 100,000 U.S. adults younger than 50, up from about 100 in 2010, according to a 2023 study in JAMA Network Open. That may seem like a small overall increase, but it’s not a good sign—especially since, during the same period of time, incidence rates among older U.S. adults decreased. “It’s almost like the curves have reversed themselves,” says Dr. Richard Barakat, director of cancer care at Northwell Health in New York. For certain types of cancer, the numbers are especially striking. Colorectal cancer is now diagnosed among young adults almost twice as often as it was in the 1990s, according to one 2022 study, and the JAMA Network Open researchers found that other types of gastrointestinal cancer are also on the rise among this population. Early-onset breast cancer is becoming more common too, with its incidence rising by almost 4% among U.S. women every year from 2016 to 2019, according to a 2024 study. Even lung cancer, a disease typically associated with older cigarette smokers, is now to a surprising degree affecting younger women, even those who have never smoked, says Dr. Matthew Triplette, a pulmonologist at Fred Hutch Cancer Center in Seattle.What’s driving these trends? Triplette says he doubts there’s “some new, very dangerous cancer risk factor out there that’s causing tons of excessive cases in younger folks.” Cancer is a complex disease influenced by a mixture of genetics, lifestyle choices, and environmental exposures, so it’s unlikely that there’s a single explanation for the data. Instead, it’s likely a mix of things. Eating lots of processed foods, not getting enough exercise, and drinking too much alcohol are all risk factors for cancer, and all of those issues are widespread in modern life. A 2019 study co-authored by Jemal found that many of the cancers growing more common among U.S. young adults are linked to obesity, which now affects about 40% of U.S. adults under 40.