A new study published in JAMA Network Open has found that cancer rates among younger Americans, particularly women and Asian or Pacific Islanders, have been increasing. The study analyzed data from 17 National Cancer Institute registries between 2010 and 2019 and identified over 560,000 cases of early-onset cancer in individuals under the age of 50.
The research revealed a 1% increase in cancer rates among Americans under 50 during the study period, with the highest increase observed in the 30 to 39 age group, which saw a 19% rise. However, cancer rates among individuals aged 50 and older actually decreased during this time.
Among different demographic groups, Asian or Pacific Islander patients under 50 experienced the largest increase in cancer rates, with a 32% spike. Hispanic patients had a 28% increase, while Black patients saw a nearly 5% decline.
The study also noted a 4.4% increase in early-onset cancer cases among women, whereas men experienced a 5% decline. Researchers believe that the rise in breast cancer cases may be responsible for the increase in women.
Breast cancer was found to have the highest case rates, while gastrointestinal cancers, including those of the appendix, colon, and bile duct, had the fastest-growing incidence rates, with a 15% increase in early-onset cases during the study period.
The researchers attribute the increase in early-onset cancers to factors such as obesity, changes in environmental exposures (such as smoke and gasoline), sleep patterns, physical activity, microbiota, and transient exposure to carcinogenic compounds.
According to the American Cancer Society, approximately 80,000 Americans between the ages of 20 and 39 are diagnosed with cancer each year, accounting for about 5% of all cancer diagnoses. Cancer is the fourth most common cause of death and the leading cause of death by disease for women in this age group, and the second most common cause of death by disease for men, after heart disease. Although women in this demographic are more likely to be diagnosed with cancer, younger men and women have equal mortality rates from the disease.
Researchers from Harvard Medical School have also investigated the rise in early-onset cancers and found that the risk increases with each generation. Factors such as a Westernized diet, lifestyle changes, and environmental factors have been identified as potential contributors to the increase in cancer rates among individuals under 50.
Overall, the findings of this study highlight the concerning trend of rising cancer rates among younger Americans, particularly in certain demographic groups, and suggest that lifestyle factors and environmental exposures may play a significant role in this increase.