A recent study led by epidemiologist Montserrat Garcia Closas has brought new insights into the rising incidence of cancer among younger adults. Three years ago, researchers from Harvard University raised concerns about a potential global epidemic of early-onset cancers, identifying a marked increase in 13 cancer types among individuals aged 20 to 49 in nearly fifty countries from 2002 to 2012. This initial research suggested various contributing factors, including sugary drinks, alcohol consumption, junk food, sedentary lifestyles, childhood obesity, antibiotic overuse, and pollution.
Garcia Closas”s latest analysis, however, reveals a more nuanced picture. It indicates that while cancer cases are indeed increasing among younger adults, this trend is limited to specific tumor types and also includes individuals over the age of 50. The study, which comprehensively examined data from 42 countries between 2003 and 2017, found a significant rise in six types of cancer among younger adults: thyroid (3.6% annual increase), kidney (2.21%), endometrial (1.66%), colorectal (1.45%), breast (0.89%), and leukemia (0.78%). Notably, all except colorectal cancer also showed increases in those over 50.
Garcia Closas emphasizes that while certain cancers are indeed on the rise among young people, focusing solely on this demographic could lead to misinterpretations. “There is a risk of misallocation of resources for research and prevention if we overlook the fact that cancer remains predominantly a disease of older adults,” she stated. This assertion is underscored by the finding that older adults are experiencing similar increases in cancer incidence for several types, including thyroid (3%), kidney (1.65%), endometrial (1.20%), breast (0.86%), and leukemia (0.61%).
The colorectal cancer incidence among younger adults appears to be an exception, as it is recognized as a genuine “global epidemic” in this age group. The analysis also revealed a moderate rise in colorectal cancer among the older population, averaging a 0.37% increase but only observed in half of the countries studied.
These six cancer types linked to rising obesity rates have prompted researchers to examine potential causes, with Garcia Closas indicating that the growing prevalence of obesity might explain part of the observed increase, though not all of it. She advocates for continued investigation into other possible contributing factors.
In contrast to the debate over the existence of a true epidemic of cancer in young adults, the World Health Organization has unequivocally identified an “epidemic of obesity.” Approximately one billion individuals are classified as obese, a significant risk factor for various malignancies and other health conditions.
Garcia Closas also noted that enhanced surveillance and improved diagnostic techniques could account for some of the increase in certain cancer types. While the incidence of the eight most prevalent cancers among those under 50 in the United States has doubled since 1992, the overall mortality from these cancers has not changed, as highlighted by researcher Gilbert Welch. He argues that many cases of early-onset cancer are being diagnosed that would have otherwise remained asymptomatic, leading to a perception that the increase is more apparent than real.
Interestingly, the analysis also indicated that the incidence of four cancer types is declining among younger adults in more than half of the countries examined. These include stomach cancer (1.62% annual decrease), esophageal cancer (0.92%), mouth cancer (0.42%), and liver cancer (0.14%). Garcia Closas speculates that a reduction in alcohol consumption in certain regions may be contributing to these declining trends, as these cancers are associated with alcohol use.
Published in the Annals of Internal Medicine, Garcia Closas”s findings call for a balanced approach to cancer research and prevention, emphasizing the importance of addressing both young and older populations. As cancer incidence continues to rise among younger adults, experts like Jose Maria Martin Moreno stress the need for increased investment in research, refined early detection programs, and intensified prevention strategies through healthy eating, physical activity, and weight management.
As the landscape of cancer incidence evolves, it remains crucial to consider the broader context of both young and older populations in the ongoing fight against this complex disease.
