A significant new study conducted by the American Cancer Society (ACS) indicates that the rates of cancer diagnoses are rising among increasingly younger generations across 17 out of 34 cancer types, such as breast, pancreatic, and gastric cancers. Alongside these rising incidence rates, death rates have also gone up for liver cancer (in women only), uterine corpus cancer, gallbladder cancer, testicular cancer, and colorectal cancer. This report is set to appear today in the journal The Lancet Public Health.
“These results contribute to the growing understanding of heightened cancer risks in generations following the Baby Boomers, broadening from earlier observations of early colorectal cancer cases and certain obesity-related cancers to include various cancer types,” remarked Dr. Hyuna Sung, the lead author of the study and a senior principal scientist at ACS focusing on surveillance and health equity. “Birth cohorts, which are groups divided based on the year of birth, experience distinct social, economic, political, and environmental factors that influence their exposure to cancer risk factors during formative years. While we have identified cancer trends connected to birth years, the precise reasons behind the rising rates remain unclear.”
In this study, researchers analyzed data from 23,654,000 patients diagnosed with 34 cancer types and mortality data from 7,348,137 deaths for 25 cancer types among individuals aged 25-84 from January 1, 2000, to December 31, 2019. The data was sourced from the North American Association of Central Cancer Registries and the U.S. National Center for Health Statistics. They calculated incidence and mortality rates specific to birth cohorts, adjusting for age and time effects across five-year intervals from 1920 to 1990.
The analysis revealed that the incidence rates for eight out of 34 cancers have increased with each new birth cohort starting from around 1920. Specifically, individuals born in 1990 showed approximately two to three times higher pancreatic, kidney, and small intestinal cancer rates compared to those born in 1955, as well as a higher rate for liver cancer among women. Moreover, in younger cohorts, incidence rates exhibited an upward trend after previously declining among older birth cohorts for nine additional cancer types, including estrogen-receptor positive breast cancer, uterine corpus cancer, colorectal cancer, non-cardia gastric cancer, gallbladder cancer, ovarian cancer, testicular cancer, anal cancer in males, and Kaposi sarcoma in males. The incidence rate for the 1990 birth cohort ranged from a 12% increase for ovarian cancer to a staggering 169% increase for uterine corpus cancer compared to the cohort with the lowest incidence. Mortality rates for liver cancer (in women only), uterine corpus, gallbladder, testicular, and colorectal cancers also rose alongside the incidence rates in younger cohorts.
“The rise in cancer rates among younger individuals indicates significant generational changes in cancer risk and often acts as an early warning for the potential future cancer burden in the country. Unless effective interventions are implemented at the population level, and as these younger individuals carry forward their heightened risk as they age, we may face an overall increase in cancer burden in the future, undermining the progress made against the disease over the past decades,” emphasized Dr. Ahmedin Jemal, senior vice president of surveillance and health equity at ACS and the study’s senior author. “The findings underscore the urgent need to identify and address the underlying risk factors affecting Generation X and Millennial populations to guide prevention efforts.”
“The escalating cancer burden among younger generations emphasizes the necessity of providing individuals of all age groups with access to affordable and comprehensive health insurance, which is a crucial factor in better cancer outcomes,” stated Lisa Lacasse, president of the American Cancer Society Cancer Action Network (ACS CAN). “In this regard, ACS CAN will persist in advocating for lawmakers to expand Medicaid in non-participating states and continue to push for the permanent establishment of enhanced Affordable Care Act tax subsidies that have improved access to care for millions.”
