As they head into their golden years, Gen-Xers are more likely to be diagnosed with cancer than the generation born before them, the Baby Boomers, a new National Cancer Institute study finds.
If current cancer trends continue, the paper published this month in JAMA Network Open concludes, “cancer incidence in the U.S. could remain unacceptably high for decades to come.”
What’s driving the projected rise in rates of invasive cancer remains an open question.
“Our study can’t speak to any particular cause,” said lead author Philip S. Rosenberg, senior investigator in the institute’s biostatistics branch. “It gives you boots-on-the-ground intelligence about what is happening. That's where you go and look for clues about causes.”
Researchers believe early detection, obesity and sedentary lifestyles might explain some of the rise in cancer rates. Some research also points to pollutants, including a class of manmade chemicals known as PFAS, as possible culprits.
Rosenberg and his team used data from 3.8 million people diagnosed with malignant cancer in the U.S. from 1992 until 2018 to compare cancer rates for members of Generation X (born between 1965 and 1980) and Baby Boomers (born between 1946 and 1964). He then ran modeling that shows that when Gen-Xers turn 60 years old (starting in 2025), they are more likely to be diagnosed with invasive cancer than Boomers were at age 60.
In fact, cancer is more likely to hit Gen-Xers than any prior generation born from 1908 through 1964, the study’s projections found.
For decades, the news about cancer had largely been encouraging. Lung cancer rates were dropping as a result of educational efforts about the harms of tobacco. In women, incidences of cervical cancer, and in men, incidences of liver, gallbladder and non-Hodgkin lymphoma also were dropping.
But the declines have been overshadowed by an alarming uptick in colorectal and other cancers in Gen-Xers and younger people.
The new study’s models found increases in thyroid, kidney, rectal, colon cancers and leukemia in both men and women. In women, it also found increases in uterine, pancreatic and ovarian cancers and in non-Hodgkin lymphoma. In men, the study also projected increases in prostate cancer.
Rosenberg was surprised about how many different types of cancer appeared to be rising at higher rates in members of Generation X compared to Baby Boomers, he said in an interview. He also was surprised that projected increases in cancer rates would offset what he described as prior “very important and impressive declines” in cancers.
The increases for Generation X over Baby Boomers appeared in all racial and ethnic groups except Asian or Pacific Islander men, who were less likely to be diagnosed with cancer at age 60 if they were Gen-Xers than Baby Boomers.
Douglas Corley, chief research officer for the Permanente Medical Group and a Kaiser gastroenterologist in San Francisco, sees generational divisions for cancer trends as “somewhat artificial,” he said in an email.
Over the past century, for example, the incidence of kidney cancer has increased steadily in young Americans. “So it is not that being part of a particular more recent generation puts you at risk,” he said. “It is not that one generation was necessarily exposed to something that others born one generation earlier were not. It is a year-by-year change.”
He believes the environment likely plays a role in the rising cancer rates.
Previous epidemiological studies point to pesticides, toxic chemicals and air pollutants as possible culprits, said Olga Naidenko, vice president of science investigations at the Environmental Working Group, who was not involved in the research. She said in an email that the U.S. should do more reduce exposure to pollutants like PFAS, or “forever chemicals,” and pesticides.
“It is absolutely essential to invest in cancer-prevention research,” she said.
Corley also pointed to obesity, increasingly sedentary lifestyles and early cancer detection as part of the picture too.
He also said it’s worth noting that the new study does not examine cancer death rates. For most cancers, earlier detection and better treatment have improved survival, Corley said.
Study author Rosenberg agrees. “We're in a situation where America's made great progress, but there's also great challenges in terms of preventing cancer,” Rosenberg said.
His data promised no reprieve for Millennials, the generation born after Gen-X.
“Is there anything that gives us hope that things are going to turn a corner for the Millennials?” he asked. “What we found is, no.”
Ronnie Cohen is a San Francisco Bay Area journalist focused on health and social justice issues.
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