Study details

For the study, researchers used an age period cohort model to analyze data from 3.8 million people diagnosed with a malignant cancer between 1992 and 2018 through the National Cancer Institute's (NCI) Surveillance, Epidemiology, and End Results Program.

They found that by the time Gen Xers turn 60, they are projected to see a cancer rate that will surpass not only baby boomers, but any other generation born between 1908 and 1964. The only exception to that was Gen X Asian or Pacific Islander males, whose rates of cancer are projected to go down. The researchers didn't have enough data points to produce any estimates for millennials.

Specifically, the researchers found that Gen X women will see significant increases over baby boomer women in rates of thyroid, kidney, rectal, corpus uterine, colon, and pancreatic cancer, as well as non-Hodgkin's lymphoma and leukemia. Meanwhile, Gen X men will see increases in thyroid, kidney, rectal, colon, and prostate cancers over baby boomers as well as leukemia.

However, rates of lung and cervical cancers are projected to decrease among Gen X women, while Gen X men are projected to see decrease in lung, liver, and gallbladder cancer, as well as non-Hodgkin's lymphoma.

"Numerous preventable causes of cancer have been identified," the study authors wrote. "Cancer control initiatives have led to substantial declines in tobacco consumption. Screening is well accepted for precancerous lesions of the colon, rectum, cervix, uterus, and breast." But despite those efforts, "other suspected carcinogenic exposures are increasing," the researchers wrote.

Specifically, the researchers called out PFAS, processed food, and "rising obesity rates and increasingly sedentary lifestyles" as contributing to the rise in cancer rates.

Discussion

Philip Rosenberg, lead author on the study and senior investigator in NCI's biostatistics branch, said he was surprised by the results of the study.

"Going in, I was anticipating that I may see colon or rectal cancer rates in particular to be as high or higher than the boomers, and that's because there's just so much of these studies coming out about early onset colorectal cancer cases," he said. "But what kind of took me more by surprise was the number of different cancer types that our models project will occur in Generation X compared to baby boomers."

Rosenberg noted that the primary purpose of the study is to "provide clues for other researchers to follow, so when you see the unexpected, that's where to look to see cancer causes and novel means of prevention." Rosenberg added that he recommends the public focus on the many recommendations that exist regarding cancer prevention.

"Spending some time thinking about those recommendations would be a great exercise for all of us—really saying, 'Am I doing everything I can?'" Rosenberg said.

Douglas Corley, chief research officer at the Permanente Medical Group and a gastroenterologist, said he sees generational divisions for cancer trends as "somewhat artificial."

For example, over the past century, rates of kidney cancer have steadily increased 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."

Corley said he believes the environment likely plays a role in rising cancer rates, as does obesity, increasing sedentary lifestyles, and early cancer detection. Corley also noted the study doesn't examine cancer death rates, and that for most cancers, early detection and better treatment have improved survival.

Olga Naidenko, VP of science investigations at the Environmental Working Group, noted that previous epidemiological studies have pointed to pesticides, toxic chemicals, and air pollutants as possible drivers behind increased cancer rates. She added that the United States should do more to reduce exposure to pollutants like PFAS and pesticides.

"It is absolutely essential to invest in cancer-prevention research," she said.

Advisory Board's oncology resources

For more insights on oncology, check out these Advisory Board resources:

Growth in demand and costs, as well as innovative technologies and disruptors, will change how cancer care is delivered, experienced, and paid for going forward. This resource outlines out four predictions for how the cancer care delivery landscape will evolve by 2030.

Separately, this expert insight explains three strategies organizations can use to leverage oncology pharmacists and improve cancer care. Similarly, these ready-to-use slides outline the major structural shifts impacting cancer care and the strategic decisions that oncology leaders will need to make.

You can also check out our upcoming webinar "Oncology market trends in 2024" on June 27. Here, we'll discuss major trends influencing today's oncology market and the implications they’ll have for stakeholders across the industry. (Greenfield, Fortune, 6/14; Cohen, NPR, "Shots," 6/20)