A new study predicts that compared with baby boomers, Gen Xers will have a higher incidence of cancer by age 60. FatCamera/Getty Images/E+ Hide caption
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A new study from the National Cancer Institute finds that Gen Xers, now entering their prime years, are more likely to be diagnosed with cancer than the baby boomers who came before them.
A paper published this month in JAMA Network Open concluded that if current cancer trends continue, “cancer incidence in the United States may remain unacceptably high for decades to come.”
The reasons for the predicted increase in the incidence of invasive cancer remain an open question.
“Our study can't speak to a specific cause,” said lead author Philip S. Rosenberg, a senior research scientist in the institute's biostatistics department, “but it provides on-the-ground information about what's going on. That's where we look for clues about causes.”
Researchers believe that early detection, obesity and sedentary lifestyle choices may be contributing factors to the rising cancer rates, and some studies have also pointed to contaminants, including man-made chemicals known as PFAS, as possible culprits.
Rosenberg and his team used data on 3.8 million people diagnosed with malignant cancers in the US between 1992 and 2018 to compare cancer incidence rates between Generation X (born between 1965 and 1980) and Baby Boomers (born between 1946 and 1964). They then used modelling to find that by the time Gen Xers turn 60 (from 2025 onwards), they will be more likely to be diagnosed with invasive cancer than Baby Boomers were at age 60.
In fact, research projects that Gen Xers are more likely to develop cancer than any other generation born between 1908 and 1964.
For decades, the news about cancer has been mostly positive: As a result of tobacco awareness efforts, rates of lung cancer were falling, as were rates of cervical cancer in women and liver, gallbladder and non-Hodgkin's lymphoma in men.
But these declines are overshadowed by an alarming increase in colon and other cancers among Generation Xers and young people.
The new model found increases in thyroid, kidney, rectal, colon, and leukemia in both men and women, as well as increases in uterine, pancreatic, ovarian, and non-Hodgkin's lymphoma in women, and predicted increases in prostate cancer in men.
In an interview, Rosenberg said he was surprised that incidence rates of various types of cancer appear to be rising among Gen Xers compared with baby boomers, and that the projected increases in cancer incidence offset “very significant and impressive declines in cancer” to date.
Increases for Gen Xers compared with Baby Boomers were seen across all racial and ethnic groups except for Asian or Pacific Islander men, who were less likely to be diagnosed with cancer at age 60 than were Baby Boomers.
Douglas Corey, chief research officer at Permanente Medical Group and a gastroenterologist at Kaiser Hospital in San Francisco, said in an email that he thinks the generational divisions in cancer trends are “somewhat artificial.”
For example, rates of kidney cancer have been steadily increasing among younger Americans over the past century. “So being part of a particular recent generation doesn't put you at higher risk,” he says. “One generation hasn't necessarily been exposed to things that other generations born a generation before them weren't exposed to. It's something that changes over the years.”
He believes the environment likely plays a role in the rising incidence of cancer.
Olga Naydenko, vice president of scientific research at the Environmental Working Group, who was not involved in the study, said previous epidemiological studies point to pesticides, toxic chemicals, and air pollutants as possible causes. In an email, she said the US needs to do more to reduce exposure to pollutants such as PFAS (“forever chemicals”) and pesticides.
“Investment in cancer prevention research is absolutely necessary,” she said.
Corley also pointed to obesity, an increasingly sedentary lifestyle and early detection of cancer as some of the reasons.
It's also worth noting that the new study didn't look at cancer mortality, Corley said, because survival rates for most cancers have improved with earlier detection and better treatments.
Study author Rosenberg agreed: “The United States has made great strides, but also has great challenges when it comes to cancer prevention,” he said.
His data didn't offer any leeway for millennials, the generation born after Gen X.
“Is there anything that gives you hope that things will get better for millennials?” he asked. “What we find is no.”
Ronny Cohen is a San Francisco Bay Area journalist focusing on health and social justice issues.
