Gen Xers will have higher cancer rates than boomers, study forecasts

Gen Xers may be more likely to be diagnosed with cancer at 60 years old than their parents' generation was, a new study forecasts. 

Scientists made this prediction after analyzing medical records from 3.8 million people in the U.S. who'd been diagnosed with different types of "invasive" cancer between 1992 and 2018. The term "invasive" refers to cancer that has spread from where it originated to surrounding tissue. 

The researchers used these data to plot "age of onset" curves, which are a graphical way of visualizing how many people are diagnosed with cancer at a particular age — in this case, 60 years old. Age is plotted on the horizontal axis of the graph, while the number of people diagnosed with cancer is on the vertical axis. By connecting the dots between the data, the full trajectory of each type of cancer within the population can be captured, and scientists can make predictions about future patterns in diagnosis rates. 

In the new study, published June 10 in the journal JAMA Network Open, researchers used these projections to estimate how many people born between 1908 and 1983 are likely to be diagnosed with cancer at a benchmark age of 60. These statistical models can uncover possible trends, but can't say why they're happening — for example, they don't take into account environmental factors that can drive cancer, or improvements in cancer screening and diagnostics. 

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The team estimated that Gen Xers, born between 1965 and 1980, are less likely per capita to develop certain cancers at age 60 than baby boomers, born between 1946 and 1964. For women, these included lung and cervical cancers, while for men, these included lung, liver and gallbladder cancers. Some of these declines were already on the public health radar; rates of lung cancer, for instance, have been falling for decades, partly because fewer people are smoking. 

The projected rates of many other types of cancers, however, were higher for Gen Xers at age 60 than boomers. For both sexes, these cancers included thyroid, kidney and colon cancers.