A troubling new study released this week shows Gen X and Millennials are more likely to get cancer than older generations. The American Cancer Society (ACS) study found that in 17 different types of cancer, including breast, pancreatic, and gastric, the incidence rates are higher for the younger generations.
Study Details and Findings

The ACS Study, published in the Lancet Public Health Journal, studied 34 types of cancer. Of those, 17 types had higher incidence rates for Gen X and Millennials. In 8 of the 17 cancers, the incidence increased by generation, and the incidence rate increased for each successive birth cohort starting in 1920.
Researcher Insights

Hyuna Sung, the lead researcher, said, “These findings add to a 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.”
Importance of Understanding Risks

The study results revealed the importance of learning, understanding, and mitigating the “underlying risk factors in Gen X and Millennial populations.” Researchers do not fully understand the cause of rising cancer rates in the younger generation, according to Ahmedin Jemal, another author in the study.
Cohort Analysis

Sung wrote, “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.”
Lack of Clear Explanation

Sung added, “Although we have identified cancer trends associated with birth years, we don’t yet have a clear explanation for why these rates are rising.”
Study Scale and Scope

The impressively large study used data from over 23 million patients diagnosed with 34 types of cancer. It spanned nineteen years, from 2000 to 2019, and study participants ranged in age from 25 to 84.
Mortality Data Evaluation

During the 19-year study, researchers evaluated mortality data, with the deaths of 7 million patients with 25 types of cancers.
Incidence Rate Comparisons

The findings of the study show that the cancer incidence rate for the year 1990 birth cohort (the youngest birth cohort) ranged from 12 percent higher than the cohort with the lowest rate for incidence of ovarian cancer up to 169 percent higher than the cohort with the lowest rate for incidence of uterine corpus cancer.
Generational Comparisons

The youngest 1990 cohort also experienced an incidence rate two-to-three times higher than the 1955 birth cohort for cancers of the pancreas, kidney, and small intestines.
Potential Future Cancer Burden

Study Author Jemal said, “The increase in cancer rates among this younger group of people indicates generational shifts in cancer risk and often serves as an early indicator of future cancer burden in the country.”
“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.”
Expert Hypotheses

In a CNN interview, Dr. Leana Wen, an emergency physician and professor at George Washington University, expounded some hypotheses about the rising incidences of the deadly disease.
Potential Causes

Wen said, “There are several hypotheses. Some researchers point to the escalating rates of obesity over the last few decades, which is associated with the risk of early-onset cancer.”
She also referenced increased consumption of ultra-processed foods and inactive lifestyles as potential contributors to higher cancer rates.
Environmental Factors

Wen also stated that some experts theorize that environmental factors are causing the increased cancer incidence, including carcinogens present in the air, water, and food younger generations are exposed to that did not exist for past birth cohorts.