Rates have continued to rise in younger generations for half of 34 cancer types covered in a new large-scale study led by American Cancer Society (ACS) researchers. These include breast, pancreatic and gastric cancers.
Even before the study was released Wednesday, doctors have been ringing the alarm about the increase of certain types of cancer in younger people.
“What we’re seeing is this remarkable and frightening increase in younger individuals over the past decade or so,” said Dr. Howard Kaufman, regional medical director of Huntington Cancer Center, an affiliate of Cedars-Sinai Cancer, in Pasadena, Calif., told Audacy’s KCBS Radio this March in an interview about colorectal cancer.
According to the new study – published in the journal The Lancet Public Health – mortality trends related to uterine corpus, gallbladder, testicular and colorectal cancers increased. They also increased for liver cancer, though only in women for that type. Researchers studied incidence data from more than 23 million patients diagnosed with 34 cancers and mortality data regarding more than 7 million deaths from 25 types of cancer for individuals age 25 years old to 84 years old from Jan. 1, 2000 to Dec. 31, 2019. Data came from the North American Association of Central Cancer Registries and the U.S. National Center for Health Statistics.
“Researchers found that incidence rates increased with each successive birth cohort born since approximately 1920 for eight of 34 cancers,” said a press release from the ACS. “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.”
After a decline in older cohorts, incidence rates also increased in younger cohorts for nine other cancers: breast cancer (estrogen-receptor positive only), uterine corpus cancer, colorectal cancer, non-cardia gastric cancer, gallbladder cancer, ovarian cancer, testicular cancer, anal cancer in male individuals, and Kaposi sarcoma in male individuals.
“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,” said Dr. Hyuna Sung, lead author of the study and a senior principal scientist of surveillance and health equity science at the American Cancer Society. She said the reason for this increased risk is not yet clear.
Back in March, Dr. Kaufman also said the increased colorectal cancer diagnoses for younger people wasn’t clear. However, he did note some factors that have been linked with colorectal cancer specifically.
“Ultra preserved foods, ultra processed foods… the consumption of red meat, which is a risk factor of processed meats and other risk factor,” he said. “But sedentary lifestyle is also an important component of this. And if you think about how our activity has changed over the past several decades, we have a generation that grew up being in front of PlayStations, TVs, gaming, and now computers where physical activity has had a marked decrease.”
Genetics could also be a factor, said Kaufman.
Dr. Ahmedin Jemal, senior vice president of surveillance and health equity science at the American Cancer Society and senior author of the study, said the new data further highlights the need to accurately identify and address underlying risk factors for these cancers in Gen Xers and millennials.
“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,” he said.
Furthermore, Lisa Lacasse, president of the American Cancer Society Cancer Action Network (ACS CAN), said the research indicates a need for “ensuring people of all ages have access to affordable, comprehensive health insurance.”