Generation X, born between 1965 and 1980, is experiencing higher rates of cancer compared to their parents’ and grandparents’ generations, a new study published in JAMA Network Open reveals.

The researchers analyzed data from 3.8 million individuals diagnosed with invasive cancer. They found that as Gen X ages, they are more likely to develop various types of cancer compared to baby boomers — born 1946–1964.

“The increases in cancer incidence in members of Generation X vs their proxy parents were substantial, especially among Hispanic women (a 34.9% increase) and men (a 14.1% increase),” the researchers wrote. “In contrast, the corresponding increases among non-Hispanic White women and men were 15.1% and 11.9%, respectively.”

The study focused on new cancer diagnoses rather than mortality rates. While there were some positive findings — including decreased rates of lung and cervical cancer in Gen X women, and lower instances of lung, liver, gallbladder cancers, and non-Hodgkin’s lymphoma in Gen X men — the overall trend remains concerning.

“Our conclusions are more concerning than previously reported increases in cancer incidence in younger age groups,” wrote the authors. “The substantial increases we identified in Generation X vs both the Baby Boomers and their proxy parents surprised us.”

The trends observed in Generation X raise concerns for Millennials, born 1981–1996, and younger generations. Although Millennials are not yet old enough to develop many types of cancer, the study’s authors warn that similar patterns might emerge as they age.