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NEW YORK – An alarming trend in the rise of early-onset cancers is emerging, with significant increases in diagnoses among individuals under 50 in the United States.
Recent analysis reveals that 14 different types of cancers are becoming more prevalent in younger populations, with breast, colorectal, kidney, and uterine cancers showing the most substantial increases. This uptick, although still representing a small percentage of overall cancer cases, could have significant implications over time.
Immediate Impact
According to the study published in Cancer Discovery, the incidence of early-onset cancers, defined as those occurring in individuals younger than 50, has been rising steadily. The largest increases have been observed in breast and uterine cancer rates across all early-onset age groups, while colorectal and certain kidney cancers have surged among those aged 30 to 49.
“A rise of a few percent per year is not a huge change in the number of diagnoses, because cancer is still rare at these ages,” said Miranda Fidler-Benaoudia, a cancer epidemiologist at Alberta Health Services and the University of Calgary. “But it’s when it’s happening over two, three decades that it really leads to a meaningful increase in that period.”
Key Details Emerge
Meredith Shiels, an epidemiologist at the National Cancer Institute, and her team analyzed data on cancers diagnosed between 2010 and 2019 in individuals aged 15 to 49. Their findings indicate that more than 80% of the additional cancer cases in 2019 compared to 2010 were breast, colorectal, kidney, or uterine cancers.
Other cancers, such as melanoma, cervical, and stomach cancers, have also seen increases in specific age cohorts, although their overall incidence remains low.
Lifestyle Changes
Several factors are believed to contribute to these increases. Obesity, a known risk factor for colorectal, kidney, and uterine cancers, has risen significantly since 1990. Although most studies linking obesity to cancer have focused on older adults, the trend in younger populations could also drive the rise in early-onset cancers.
One 2024 study suggests that more than half of uterine cancers diagnosed in 2019 might be linked to obesity.
Changes in reproductive patterns, such as earlier menstruation and later childbirth, may also contribute to the increased incidence of early-onset breast cancers. Additionally, the use of oral contraceptives has been linked to a slight increase in breast cancer risk, although it may offer protective benefits against other types.
Better Detection
Advancements in cancer screening and detection have resulted in more early-onset cancers being diagnosed. Individuals with genetic predispositions, such as BRCA gene variants, are now being screened earlier, leading to a rise in detected cases.
“Newer screening guidelines recommend people with these genes start screening for cancer earlier than those with an average risk,” Shiels noted.
Increased incidental detection during unrelated medical tests has also contributed to the rise in kidney cancer diagnoses.
Environmental Exposures
Exposure to certain environmental factors during prenatal or early life stages may also play a role. Research published in Nature suggests that childhood exposure to colibactin, a chemical produced by specific E. coli strains, is linked to DNA mutations in early-onset colorectal cancers.
“I think that we need large studies that follow individuals over the life course, including at younger ages, to be able to identify risk factors for early-onset cancers,” Shiels emphasized.
What Comes Next
Despite the challenges in pinpointing exact causes, the trend of increasing early-onset cancer cases demands attention and further research. Large-scale studies are essential to better understand and mitigate these risks, especially as these cancers, although still rare, continue to rise among younger populations.
As the medical community seeks to address these alarming trends, ongoing research and public health initiatives will be crucial in managing and potentially reversing the rise of early-onset cancers.
