A recent study has provided an in-depth analysis of cancer rates across generations in the United States. The researchers examined and compared cancer diagnosis and mortality rates among different age groups over time. Their findings revealed that Gen X and Millennials have cancer incidence rates two to three times higher than those born around 1955. Furthermore, these generations are at greater risk for developing 17 specific types of cancer. The study highlighted environmental toxins, dietary habits, and obesity as key contributors to this increase. However, the authors emphasized that further research is needed to identify additional factors driving the rising cancer rates.
The same research team conducted a related study in 2019, which identified a rise in eight types of cancer among more recent generations. However, prior to this new study, no research had examined both cancer incidence and mortality by birth year together. This latest study aimed to fill that significant gap in the available data. The researchers noted that early-life exposure to carcinogens influences cancer rates in individuals aged 50 and under. As these younger generations age, their elevated risk means that cancer cases are likely to increase in the future.
The study analyzed data from 23,654,000 individuals diagnosed with 34 different types of cancer, alongside information on 7,348,137 deaths caused by 25 types of cancer. This data covered diagnoses and deaths occurring between 2000 and 2019. The researchers found that 17 of the 34 cancer types showed an increased incidence among Gen X and Millennials:
- Small intestine
- Cardia gastric
- Ovary
- Estrogen receptor-positive breast
- Non-HPV-associated oral and pharynx (in females)
- Liver and intrahepatic bile duct (in females)
- Kaposi sarcoma (in males)
- Anus (in males)
- Colorectal cancer
- Endometrial cancer
- Gallbladder and other biliary
- Pancreas
- Kidney and renal pelvis
- Myeloma
- Non-cardia gastric
- Leukemia
The rise in cancer incidence was particularly notable for cancers of the pancreas, kidneys, renal pelvis, thyroid, and small intestine. In addition, mortality rates increased for five types of cancer: liver, endometrial, gallbladder, testicular, and colorectal cancers. These findings are alarming because they suggest that the elevated cancer risk among Gen X and Millennials is not simply due to improved detection and diagnosis. Rather, they point to a true and troubling increase in cancer risk across the population. The growth in new cases is occurring so quickly that it is outpacing advances in treatment.
While the study focused on gathering new data about cancer incidence, it did not specifically identify the causes behind the increase. Nevertheless, the researchers acknowledged several known contributing factors. Obesity stood out as a major concern, being linked to 10 of the 17 cancers highlighted in the study. The prevalence of obesity has risen across all age groups since the 1970s, with the fastest increase observed among children and adolescents aged 2 to 19. Other contributing factors mentioned include exposure to environmental pollutants, disrupted sleep patterns, and sedentary lifestyles.
The rise in cancer incidence has also been associated with the typical Western diet, which is often high in processed foods rich in sugar, saturated fats, and refined grains. These heavily processed foods contribute not only to weight gain but have also been directly linked to a higher risk of colorectal and breast cancers. Because some cancers affecting the digestive system are not connected to obesity, researchers suspect that changes in the gut microbiome may play a role. They propose that both Western dietary habits and widespread antibiotic use significantly impact the composition of the gut microbiome.
Overall, the study highlighted a significant rise in the incidence of 17 types of cancer among Gen X and Millennials. However, there is some positive news as well—certain cancers are actually decreasing. For example, women born around 1990 are now less likely to develop cervical cancer, largely due to the introduction of HPV vaccinations when they were in their teens. Additionally, declining smoking rates have contributed to reductions in esophageal, laryngeal, and lung cancers. Despite the overall increase in cancer incidence within these generations, improved early detection methods have helped lower mortality rates.
Our knowledge of cancer and its underlying causes continues to expand alongside improvements in treatment. Yet, many health problems in later life can be traced back to influences experienced during youth. The study identified a rise in 17 types of cancer among Gen X and Millennials, raising concerns about the modern-day factors impacting these generations. However, there is still hope. Despite the overall increase in cancer cases, certain lifestyle changes have contributed to declines in some cancer types.
