A new study led by researchers at the American Cancer Society (ACS) found that cancer incidence rates have been increasing in successively younger generations for 17 out of 34 cancer types, including breast, pancreatic, and gastric cancers. Mortality trends also rose in conjunction with the incidence of liver, uterine corpus, gallbladder, testicular, and colorectal cancers. These findings suggest a growing cancer risk in post-Baby Boomer generations, affecting a broader range of cancer types than previously seen. The study, to be published in The Lancet Public Health, analyzed data from over 23 million cancer patients and 7 million cancer-related deaths from 2000 to 2019, comparing cancer rates across generations from 1920 to 1990.
The researchers found that incidence rates for certain cancers increased with each successive birth cohort born since around 1920, with rates up to two-to-three times higher in the 1990 birth cohort compared to the 1955 birth cohort for cancers such as pancreatic, kidney, and small intestinal cancers. Additionally, incidence rates rose in younger cohorts for cancers like breast cancer (estrogen-receptor positive only), uterine corpus cancer, colorectal cancer, and gallbladder cancer. Mortality rates also increased in younger birth cohorts alongside the incidence rates for liver cancer (female only), uterine corpus, gallbladder, testicular, and colorectal cancers. These findings suggest generational shifts in cancer risk and could lead to a future increase in cancer burden without effective population-level interventions.
Dr. Hyuna Sung, lead author of the study and a senior principal scientist at ACS, noted that birth cohorts share unique social, economic, political, and climate environments that can affect their exposure to cancer risk factors during crucial developmental years. While the study identified cancer trends associated with birth years, the reasons for the rising rates are not yet clear. The research highlights the critical need to identify and address underlying risk factors in Generation X and Millennial populations to inform prevention strategies and mitigate future cancer burden. Dr. Ahmedin Jemal, senior vice president at ACS, emphasized the importance of addressing the increased cancer risk among younger generations to maintain progress against the disease.
Lisa Lacasse, president of the American Cancer Society Cancer Action Network (ACS CAN), emphasized the importance of ensuring people of all ages have access to affordable, comprehensive health insurance to improve cancer outcomes. She urged lawmakers to expand Medicaid in states that have not yet done so and advocated for making permanent the enhanced Affordable Care Act tax subsidies that have increased access to care for millions. The increasing cancer burden among younger generations underscores the need for interventions and policies that prioritize prevention and access to healthcare for all individuals. The study’s findings serve as a call to action to address the rising cancer rates among younger populations and implement strategies to reduce future cancer burden.