Younger generations are facing a higher likelihood than their parents and grandparents of contracting half of the main cancer types.
An American Cancer Society study said this included breast, pancreatic and gastric cancers.
The study report, published in the Lancet Public Health journal, said post-Baby Boomer generations had higher incidence rates for 17 of the 34 cancer types examined.
The researchers reviewed data from 23.6 million United States patients diagnosed with 34 types of cancer, and mortality data from 7.3 million deaths from 25 types of cancer for individuals aged 25–84 from 2000 to 2019.
Study lead author Hyuna Sung said full reasons for the rising cancer rates were still to be determined.
“These findings add to growing evidence of increased cancer risk in post-Baby Boomer generations, expanding on previous findings of early-onset colorectal cancer and a few obesity-associated cancers to encompass a broader range of cancer types,” Dr Sung said.
“Birth cohorts, groups of people classified by their birth year, share unique social, economic, political, and climate environments, which affect their exposure to cancer risk factors during their crucial developmental years.”
Researchers found that incidence rates increased with each successive birth cohort born since approximately 1920 for eight of 34 cancers.
“In particular, the incidence rate was approximately two-to-three times higher in the 1990 birth cohort than in the 1955 birth cohort for pancreatic, kidney, and small intestinal cancers in both male and female individuals, and for liver cancer in female individuals,” the study report said.
The researchers said the increase in cancer rates among younger groups indicated generational shifts in cancer risk and often served as an early indicator of future cancer burden.
“Without effective population-level interventions, and as the elevated risk in younger generations is carried over as individuals age, an overall increase in cancer burden could occur in the future, halting or reversing decades of progress against the disease,” the study report said.
“The data highlights the critical need to identify and address underlying risk factors in Gen X and Millennial populations to inform prevention strategies.”
The full report is on the American Cancer Society website.
